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Diagnosing primary central nervous system lymphoma (PCNSL) frequently requires neurosurgical biopsy due to nonspecific radiologic features and the low yield of cerebrospinal fluid (CSF) studies. We characterized the clinical evaluation of suspected PCNSL (N = 1007 patients) and designed a rapid multiplexed genotyping assay for MYD88, TERT promoter, IDH1/2, H3F3A, and BRAF mutations to facilitate the diagnosis of PCNSL from CSF and detect other neoplasms in the differential diagnosis. Among 159 patients with confirmed PCNSL, the median time to secure a diagnosis of PCNSL was 10 days, with a range of 0 to 617 days. Permanent histopathology confirmed PCNSL in 142 of 152 biopsies (93.4%), whereas CSF analyses were diagnostic in only 15/113 samplings (13.3%). Among 86 archived clinical specimens, our targeted genotyping assay accurately detected hematologic malignancies with 57.6% sensitivity and 100% specificity (95% confidence interval [CI]: 44.1% to 70.4% and 87.2% to 100%, respectively). MYD88 and TERT promoter mutations were prospectively identified in DNA extracts of CSF obtained from patients with PCNSL and glioblastoma, respectively, within 80 minutes. Across 132 specimens, hallmark mutations indicating the presence of malignancy were detected with 65.8% sensitivity and 100% specificity (95% CI: 56.2%-74.5% and 83.9%-100%, respectively). This targeted genotyping approach offers a rapid, scalable adjunct to reduce diagnostic and treatment delays in PCNSL., (© 2021 by The American Society of Hematology.)

Because work hour restrictions and technological developments such as staplers change the surgical landscape, efficient resident training methods are necessary to ensure surgical quality. This study evaluates efficacy of a porcine skills laboratory for teaching surgery residents to perform handsewn intestinal anastomoses based on a validated subjective tool and novel objective measurements. We hypothesized that resident performance would improve postintervention; junior residents would improve more than the seniors would. This prospective study was completed over a period of four months in 2015. Participants performed standardized two-layer, handsewn, end-to-end small intestine anastomosis in a live porcine model before (pretest) and after (posttest) an educational intervention. The intervention consisted of an instructional module and skills laboratory teaching session by attending surgeons. Participants were evaluated based on objective measurements of the anastomosis and blinded video evaluations using objective structured assessment of technical skills. Twenty-eight residents in a six-year general surgery program started and completed the study. The objective structured assessment of technical skills ratings demonstrated that the whole resident cohort had statistically significant improvement in pre- to posttest scores, 11.16 to 24.59 ( P < 0.001). Junior and senior residents improved independently, 9.59 versus 22.53 ( P < 0.001) and 13.59 versus 27.77 ( P < 0.001), respectively. Finally, the cohort significantly improved in number of full-thickness Lembert sutures (2.36 vs 0.93, P = 0.001) and time to completion (31.28 vs 28.2 minutes, P = 0.046). Anastomotic leak pressure, anastomotic narrowing, and anastomotic tensile strength all trended toward improvement. A structured educational intervention, teaching intestinal anastomosis in a live porcine model produced significant improvement in residents' technical skills.

Background: In patients with chronic mesenteric insufficiency (CMI), traditional bypass surgery carries a high operative mortality. Endovascular therapy for reconstruction of the mesenteric vascular system has high technical success but poor long-term patency. Secondary procedures are often mandatory for recurrent disease. The purpose of this study was to evaluate an endovascular-first treatment strategy for CMI, reserving open reconstruction for complex disease patterns without an endovascular option., Study Design: Data for consecutive adult patients (N = 107) initially treated with endovascular techniques for CMI were reviewed. The management algorithm consisted of postoperative and biannual ultrasound and clinical follow-up., Results: A total of 107 patients with CMI were treated from April 2004 through June 2010. Technical success for endovascular reconstruction was 100%. Long-term follow-up data were available on 90% of patients. After the index procedure, 57% of patients (n = 55) had complete resolution of the preoperative symptoms. During the management phase, 83% of patients had elevated velocities on duplex evaluation. During this interval, 53% of patients required no further intervention after the index procedure, and the remaining patients required an additional 78 procedures. Five patients required open revascularization for recurrent disease, and only 2 patients died from complications of mesenteric insufficiency., Conclusions: Endovascular management for CMI has a high technical success rate with low morbidity and mortality. Regular follow-up is essential to optimize patient outcomes. Ultrasound findings alone are a poor predictor of recurrent disease. Long-term success requires adaptation of a management program to elicit recurrent symptoms and offer prompt treatment., (Copyright © 2011. Published by Elsevier Inc.)

Transanal excision of rectal tumors may be performed using the Ferguson Operating Anoscope (FOA). This retrospective case series evaluates the effectiveness of FOA for the excision of selected benign and malignant rectal tumors. The office records of 97 patients with rectal tumors who underwent FOA transanal excision by a single surgeon from 1999 through 2009 were reviewed. In the 97 patients evaluated, 99 FOA transanal excisions were performed for 39 adenocarcinomas, 55 benign tumors, and five carcinoid tumors. The tumors were 0.5 to 13.5 cm in diameter and located an average of 6.9 cm (range, 1 to 15 cm) from the anal verge. Ninety-one per cent of cases were performed as an outpatient. Postoperative complications occurred in 14 per cent with transient effects on continence in 2 per cent and a mean blood loss of 66 mL. The recurrence rate for favorable T1 rectal cancers was 4.3 per cent and for adenomas was 5.9 per cent. In early follow up of adenomas and favorable T1 carcinomas, FOA transanal excision has similar application, morbidity, and recurrence rates as reported for transanal endoscopic microsurgery for rectal tumors within 15 cm from the anal verge. FOA may be considered a useful option for the minimally invasive treatment of rectal tumors.

The rural surgery rotation that is contained within the general surgery residency program at The University of Tennessee College of Medicine-Chattanooga is described in this article. The advantages of this experience, including the extensive endoscopy experience and the close exposure to practicing general surgeons, are also outlined. The rotation receives uniformly positive evaluations from residents at completion, and it has become the primary gastrointestinal endoscopy educational experience in this program. The description serves as a model that can be used by other programs to construct a rural surgery rotation.

Heavy metal toxicosis is a well-known phenomenon in wild, captive-animal, and domestic animal medicine. However, the occurrence among reptiles is not well documented. One reason for this is the lack of information regarding reference blood and tissue levels of heavy metals in reptiles. To determine normal blood lead, plasma zinc, and liver lead and zinc concentrations, blood and liver samples were collected from 4 adult and 16 juvenile, healthy green iguanas (Iguana iguana). Lead and zinc levels were measured using atomic absorption spectroscopy. Using the mean +/- two SD as the normal reference range, the present study suggests the following for captive common green iguana: 1) whole blood lead level: 0.06 +/- 0.06 microg/ml; 2) plasma zinc level: 2.68 +/- 1.66 microg/ml; 3) liver lead level (wet-weight basis): <1.0 +/- 0.0 microg/g; 4) liver lead level (dry-weight basis): <3.0 +/- 0.0 microg/g; 5) liver zinc level (wet-weight basis): 24.9 +/- 11.6 microg/g; and 6) liver zinc level (dry-weight basis): 83.4 +/- 44.6 microg/g. These values are fairly consistent with published reference levels in other mammalian and avian species.

Methicillin-resistant Staphylococcus aureus (MRSA) is increasingly responsible for infections in hospitalized patients. Patients colonized with MRSA appear to be at higher risk for subsequent MRSA infections than those who are not colonized. In this study, we determined MRSA colonization status of trauma patients at hospital admission and compared the incidence of subsequent MRSA infections between MRSA colonized and noncolonized patients. Collected data were entered into databases at a single, Level I trauma center over a 13-month period. Three hundred fifty-five adult trauma patients were screened for MRSA on admission to the trauma intensive care unit. The patients were categorized into two groups, those colonized with MRSA at admission and those who were not. Thirty-six of 355 patients (10.1%) were colonized. Of the 319 patients not colonized, 21 (6.6%) developed MRSA infections. Twelve of 36 (33.3%) colonized patients developed MRSA infections (P < 0.001). No differences in types of MRSA infections were found between the two groups. Colonized patients who developed MRSA infections had higher death rates, 22.2 versus 5.0 per cent (P < 0.001). Patients colonized with MRSA on admission may be at higher risk for developing MRSA infections during hospitalization. MRSA screening protocols should be used to identify these at-risk patients.

Background: The number of surgeons willing to practice general surgery in its traditional form is in decline. One becomes acutely aware of this shortage, as a residency program director, given the many requests for new general surgeons (GS)., Study Design: From the 7th of February 2007 through the 30th of April 2007, and from May 23, 2007 through August 10, 2007, one program director collected all solicitations and advertised openings sent to him for a new GS. These communications varied from email submissions to formal letters. To assess the economic impact of a GS on a hospital, data were collected from existing recruiting industry surveys, the chief financial officer of a large inner-city teaching hospital, and an individual rural surgeon., Results: There were 140 openings nationally for GSs during the initial study period. During the second study period, there were 149 positions in 40 states. The annual economic worth of a GS was estimated to be between $1.05 million and $2.4 million., Conclusions: Currently, there is an imbalance in supply and demand for the field of general surgery. If GSs retire or leave small hospitals and cannot be replaced, those hospitals will be threatened with closing. This will strain the large, safety-net hospitals even more. Solutions should include a national workforce survey, allowing hospitals to supplement a surgeon's income, the Residency Review Committee for Surgery should consider an immediate 20% increase in the number of categorical spots in general surgery, and focused recruitment of medical graduates from other countries.

With the development of expertise in image guidance for breast surgery, many surgeons now perform preoperative wire localization themselves. Use of a single wire versus multiple wires to bracket a radiographic breast abnormality has previously been described, although benefits of this technique based on clinical outcomes such as margin status, tissue volume removed, and re-excision rates have not been established. This study is a retrospective analysis of wire-localized breast biopsies performed by 14 surgeons over 29 months; stereotactic and ultrasound guidance were used. During this time, 489 wire localizations were done, of which 159 used multiple wires. Two hundred eleven of these biopsies were done for malignant disease, 86 using multiple wires. After controlling for tumor node metastases stage, single and multiple wire placements were compared using endpoints of margin status, need for re-excision, and total volume of tissue removed. Neither margin status nor re-excision was related to the number of wires placed. However, the number of wires placed was significantly related to the total volume of tissue removed. Use of more than one localizing wire was associated with greater volume of tissue removal (measured in centimeters cubed) in benign disease (46 vs 25, P < 0.001), equivalent volumes in stage 0 disease (73 vs 67), less volume in stage 1 disease (113 vs 164), and less volume in stages 2 through 4 (158 vs 207, P = 0.03). Outcomes based on surgeon case volume during the study period demonstrated that low- (1-40), medium- (41-80), and high-volume (>80) surgeons did not differ in the type or stage of breast pathology treated. Surgeons with high case volumes were more likely to place multiple localizing wires (P < 0.001) and were more likely to do a breast-conserving procedure if re-excision was performed (P < 0.018). Surgeons with low case volumes were more likely to perform a re-excision (P < 0.025). Surgeon experience has a positive impact on quality outcome measures such as performance of a definitive procedure at the time of initial surgery and use of breast-conserving procedures at the time of re-excision. Multiple wire localization can be used to significantly reduce the volume of breast tissue removed in malignant disease without sacrificing margin status or increasing the need for future re-excision.

Background: Temporary closure of an open abdominal wound by vacuum-pack is the method of choice for patients requiring open abdomen management in our institution. We have previously reported our experience with a vacuum-pack in trauma patients and have expanded its use to general and vascular surgery patients., Study Design: This is a descriptive study performed through review of medical records of all patients undergoing vacuum-pack closure after celiotomy from January 1999 to May 2006. Clinical and demographic data were collected., Results: Seven hundred seventeen vacuum-pack closures were performed in 258 surgical patients (116 trauma versus 142 general and vascular surgery). The most common indication for open abdomen management was damage control in trauma patients and planned reexploration in general and vascular surgery patients. Total abdominal complication rate was 15.5% (14.7% trauma versus 16.2% general and vascular surgery). Fistulas occurred in 13 (5%), intraabdominal abscesses in 9 (3.5%), bowel obstruction in 3 (1.2%), abdominal compartment syndrome in 3 (1.2%), and evisceration in 1 (0.4%). Two hundred twenty-six patients survived to permanent abdominal wound closure. Of these, 154 (68.1%) patients underwent primary fascial closure of their abdominal wounds. Seventy-two patients (31.9%) required delayed closure. In-hospital mortality rate was 26.0% (25.9% trauma versus 26.1% general and vascular surgery). The cost of vacuum-pack materials is less than $50., Conclusions: Indication for open abdomen management varied between general and vascular surgery and trauma patients. Complication rates were similar. Primary closure of open abdominal wounds was achieved in 68.4% of patients. Vacuum-pack temporary abdominal wound closure, initially used in trauma patients, continues to demonstrate ease of mastery, effectiveness in patient care and comfort, consistently low associated complication rate, and low cost in both general and vascular surgery and trauma patients.

Background: Clearance of the cervical spine after blunt trauma remains controversial in patients with normal radiologic evaluation., Methods: Blunt trauma patients with midline boney cervical tenderness and plain films that disclose no abnormalities and computed tomography (CT) scans were entered into a care pathway for spinal clearance using the Bolster or active range-of-motion (AROM) flexion/extension techniques. The quality of films between the two techniques was then compared., Results: In all, 159 patients entered the pathway with 14 patients (9%) unable to complete the examination secondary to pain. The Bolster was used in 129 patients (89%) and AROM was used in 16 (11%). The total range of motion was significantly better with AROM at 51.4 +/- 19.4 degrees of motion compared with 32.0 +/- 13.0 degrees with the Bolster (p < or = 0.05). The most distal level visualized was not different between groups with 6.6 +/- 0.8 cervical vertebrae visualized on average in the Bolster group and 6.8 +/- 0.7 in the AROM group. Positive findings occurred in five patients (3.4%) in the Bolster group., Conclusion: The incidence of occult cervical injury in patients with boney cervical pain despite normal plain films and CT scans in this study was 3.4%. The AROM technique has better total range of motion than the Bolster, although results of the Bolster technique remain within acceptable standards. The present care pathway appears to be an effective screening tool for evaluation of this population of patients. Additional evaluation of the obtunded patient is necessary before broad implementation of this technique.

Background: Airway pressure-release ventilation (APRV) is a pressure-limited, time-cycled mode of mechanical ventilation. The purpose of this study was to evaluate our initial experience with the use of APRV in acutely injured, ventilated patients., Methods: Since March 2003, APRV has been used selectively in adult trauma patients with or at risk for acute lung injury/acute respiratory distress syndrome. Data were obtained before and during the 72 hours after switching to APRV. A retrospective analysis of these data was then performed., Results: Complete data were available on 46 of 60 patients (77%) for the first 72 hours of APRV. Before APRV, the average Pao2/Fio2 ratio was 243 and the average peak airway pressure was 28 cm H2O. Peak airway pressure decreased 19% (p = 0.001), Pao2/Fio2 improved by 23% (p = 0.017) and release tidal volumes improved by 13% (p = 0.020) over the course of the analysis., Conclusion: APRV significantly improved oxygenation by alveolar recruitment and allowed for a reduction in peak airway pressures. This relatively new modality had favorable results and appears to be an effective alternative for lung recruitment in traumatically injured patients at risk for acute lung injury/acute respiratory distress syndrome.

The Accreditation Council for Graduate Medical Education (ACGME) requires all programs to limit resident work hours to 80 hours per week with some programs allotted an extra 10 per cent for specific educational purposes. The purpose of this study was to evaluate data reflecting changes in resident schedules made in 2002-2003 to be compliant with ACGME requirements without compromising patient care or resident education. Surgery residents originally completed a work-hour survey in May 2002. The survey contained 14 daily time sheets. Residents were asked to document how their time was spent between 14 different categories delineating in-house and out-of-house hours. Changes were made to resident schedules in order to become compliant with the new regulations. After making changes in the schedule, two more surveys were completed and evaluated, once in May 2003 and again in November 2003. Final analyses compared results from May 2002 to November 2003. Surveys were distributed to 30 residents in May 2002. Twenty-two residents completed the survey with 16 surveys eligible for analysis following exclusion of abnormal rotations (i.e., research and vacation). Eighty-eight per cent of junior residents (PGY 1, 2, and 3), 50 per cent of senior residents (PGY 4-5), and 33 per cent of chief residents (PGY 6) worked more than 88 hours per week. In November 2003, surveys were sent to 32 residents. Twenty-four residents who were on our normal call schedule completed the survey. Fourteen per cent of junior residents, 33 per cent of senior residents, and 0 per cent of chief residents worked more than 88 hours per week. By making the changes described, we have substantially reduced the number of resident work-hours while maintaining our academic and patient care missions.

Lower extremity fractures (LEFx) and pelvic fractures (PFx) are believed to increase the risk of lower extremity deep vein thrombosis (LEDVT). We studied trauma patients at high risk for LEDVT to determine whether an increased incidence of LEDVT was associated with LEFx and/or PFx. From January 1995 through December 1997 4163 trauma patients were admitted to our Level I trauma center. One thousand ninety-three patients at high risk for LEDVT were screened with serial lower extremity venous duplex ultrasound. Their medical records were retrospectively reviewed for demographics, mechanism of injury, and fracture data. The occurrence of LEDVT, pulmonary embolus, and LEDVT prophylaxis and treatment were noted. The incidence of LEDVT in the fracture group (Fx) was compared with that in the nonfracture group (NFx) using chi-square analysis and logistic regression. Statistical significance was set at < or = 0.05. Complete data were available for 1059 of 1093 patients. Five hundred sixty-nine (53.73%) patients had PFx and/or LEFx, 151 (14.26%) patients had PFx only, 317 (29.3%) patients had LEFx only, and 101 (9.54%) patients had both PFx and LEFx. Four hundred ninety (46.27%) patients had NFx. In 1059 patients LEDVT was detected in 125 (11.8%). Sixty-three patients in the Fx groups developed LEDVT (50.4%): 19 (15.2%) PFx patients, 15 (12.0%) PFx/LEFx patients, and 29 (23.2%) LEFx patients. Sixty-two (49.6%) NFx patients developed LEDVT. LEDVT incidence was not significantly different between the Fx and NFx groups or among the PFx, LEFx, and PFx/LEFx groups (P = 0.317). Nine patients developed pulmonary embolism: four NFx patients, two LEFx patients, two PFx patients, and one PFx/LEFx patient. Significant predictors of LEDVT were age and hospital length of stay. Mean age in patients with LEDVT was 47.58 years and in patients without LEDVT it was 40.89 years (P < 0.001). Mean hospital length of stay in patients with LEDVT was 29.81 days and in patients without LEDVT it was 16.84 days. The power of this study to detect differences representing medium effect sizes was greater than 90 per cent. We conclude that LEFx and/or PFx was not associated with an increased incidence of LEDVT in trauma patients at high risk for LEDVT. Lower extremity venous duplex ultrasound needs to be performed in both Fx and NFx groups to detect LEDVTs.

The purpose of the present investigation was to determine whether enzyme-treated (ET)-NRL is less immunogenic than untreated NRL in a BALB/c mouse model of primary in vivo sensitization following repeated subcutaneous injections with the aqueous phase of ammoniated NRL or ET-NRL. Mice immunized with NRL produced IgE against NRL and ET-NRL, indicating that protease treatment did not completely destroy IgE antibody epitopes. In contrast, ET-NRL-immunized mice did not produce IgE against either NRL or ET-NRL, suggesting that enzyme treatment reduced the number of antigenic polypeptides associated with NRL below the threshold for sensitization. Thelper-lymphocytes from NRL-immunized mice proliferated and produced IL-4 when stimulated in vitro with polypeptides from NRL, but not ET-NRL. In contrast, Thelper-lymphocytes from ET-NRL-immunized mice were nonresponsive to ET-NRL or NRL. We conclude that lack of IgE production by ET-NRL-immunized mice is likely related to a lack of T-cell help in the form of IL-4, rather than enzyme digestion of IgE antibody epitopes. These data indicate that there is an immunologic rationale for production of enzyme-treated NRL-containing medical devices.

Stereotactic core needle biopsy (SCNB) is a sensitive and specific indicator of breast pathology. Commonly the first biopsy core is taken from the center of the lesion in question. Multiple cores are then taken from points peripheral to the central core. The sensitivity and specificity of the central core to diagnose breast disease is unclear. We compared the pathology of the central core biopsy with that of the remaining cores in a prospective study to determine the sensitivity and specificity of the central core to diagnose breast disease. All patients undergoing SCNB for breast lesions in a single surgical office during a 7-month period were eligible for inclusion. One hundred thirty-three patients with first cores from 145 biopsy sites were included. The histologic diagnosis from 117 (81%) of the first cores from these 145 biopsy sites were representative of their respective samples as a whole. Seventy-seven (53%) of the first cores were in complete agreement with the final histologic diagnosis whereas 40 (28%) had minor differences with the histologic diagnosis that had little or no clinical significance. Twenty-eight (19%) central core samples did not agree with the final pathologic diagnosis. Seven of these 28 patients each had a final diagnosis of cancer missed by the central core biopsy. The first core sample had a sensitivity for cancer detection of 79 per cent and specificity 100 per cent. SCNB remains a sensitive and specific identifier of breast pathology. When mammographic evidence of calcifications was the primary indication for SCNB (n = 75) calcification was present in the central core in 51 (68%). In these 51 patients the central core biopsy was in agreement with the final histologic diagnosis in 46 (90%) specimens. Histologic review of the first core sample alone lends no increased benefits and in fact misrepresents the pathology present in a significant number of patients. When analyzed as an independent predictor of breast pathology the first core is a more sensitive indicator than subsequent individual cores, but the most accurate predictor of pathology is examination of the entire group of core samples. This study confirms the need for acquisition of multiple cores from each lesion in question.

The purpose of this study was to determine the effectiveness of the Thow long intestinal tube (LIT) for prevention of postoperative adhesive small bowel obstruction (ASBO) and to compare the Thow tube with other LITs. The charts of all patients who had placement of a Thow tube between January 1986 and November 1998 were reviewed. Thirty-four patients ranging in age from 9 to 86 years (mean 57.9) were included in the study. Twenty-five were contacted by phone for long-term follow-up. Twenty-nine patients had undergone previous abdominal surgery, and in 11 of 29 the previous surgery was for ASBO. Indications for surgery and Thow tube placement included: bowel obstruction (25), perforated viscus (five), carcinomatosis (two), colitis (one), and atonic bowel (one). Review of the operative notes revealed no difficulty in advancing the Thow tube in 32 of 34 patients (94%). Thow tube-related complications occurred in nine patients (25%). All complications were associated with the gastrostomy site, and only one patient required surgery for the complication. Two (5.9%) patients developed recurrent obstruction during a mean follow-up of 52 months. In one patient the obstruction was caused by adhesions and in another it was the result of an intra-abdominal abscess. Of 23 patients treated for ASBO at the time of Thow tube placement no patient (0%) developed recurrent ASBO during the follow-up period (total 110.5 patient-years). This study along with a review of the literature suggests that LITs decrease the risk of recurrent ASBO. The Thow tube, however, is easily placed and is associated with fewer and less severe complications than other LITs.

Abdominal distention is a common clinical sign in guinea pigs and may have many causes. Abdominal ultrasonography may be a useful diagnostic tool in differentiation of abdominal disorders in guinea pigs. Ovariohysterectomy is indicated for granulosa cell tumors and cystic rete ovarii in guinea pigs.

We evaluated the efficacy of subatmospheric pressure and hyperbaric oxygen (HBO) as adjuncts in the treatment of hypoxic full-thickness wounds in a rabbit model. We hypothesized that subatmospheric pressure and HBO independently are effective in improving wound healing in the ischemic wound model and that when they are used in combination there is an increased positive effect on wound healing. Using a standard ischemic wound model four full-thickness wounds were created on each ear of 41 male New Zealand white rabbits (N = 82 ears). On each rabbit one ear was dressed with the vacuum-assisted closure (VAC) device and connected to suction; the other was dressed identically without the suction and suction tubing. Twenty rabbits were treated with HBO daily for 10 days at 2.0 atmospheres absolute for 90 minutes plus descent and ascent times. Necropsy on all rabbits was performed on postoperative day 10. Four ischemic wound treatment groups were evaluated: Group 1 (N = 21) VAC dressing alone; Group 2 (N = 20) VAC dressing plus HBO; Group 3 (N = 21) VAC dressing to suction alone; and Group 4 (N = 20) VAC dressing to suction and HBO. Using light microscopy a veterinary pathologist blinded to treatment groups quantified peak granulation tissue, granulation tissue gap, and epithelialization tissue gap. Data were analyzed by analysis of variance with significance indicated by P < 0.05. Statistical significance was found in a comparison of VAC dressing to suction and VAC dressing alone for peak granulation tissue and granulation tissue gap both with and without use of HBO. VAC device use appears to increase the rate of healing in a rabbit ischemic wound model. HBO therapy did not significantly affect the rate of healing in this model.

Objective: To evaluate the reliability of stereotactic core-needle breast biopsy (SCNB) performed by surgeons to detect histologically benign tissue., Summary Background Data: Stereotactic core-needle breast biopsy is widely used to obtain tissue for definitive pathologic diagnosis of mammographically suspicious breast lesions. It has an incidence of malignancy detection similar to that of open biopsy. The potential for sampling error is a concern. Minimal data regarding follow-up and failure rate are available, especially from series performed exclusively by surgeons., Methods: Pertinent medical records of all patients who underwent SCNB between April 1995 and October 1997 were reviewed. Breast lesions were classified by mammographic Breast Imaging-Reporting and Data Systems (BI-RADS) categories before SCNB. Benign biopsy specimens were classified as nonproliferative or proliferative. Malignant lesions and those with atypical histopathology by SCNB were excluded from this analysis. All lesions initially reported as benign were followed up mammographically for at least 2 years for any suspicious change requiring repeat biopsy., Results: During the 31-month period, SCNB was performed on 694 lesions in 619 patients. Histologic evidence of malignancy was found in 112 lesions (16%). The initial histologic diagnosis for the remaining 582 lesions was benign. Four hundred lesions were available for follow-up; of these, 373 (93%) were mammographically categorized as BI-RADS 3 (probably benign) or 4 (suspicious). Three hundred forty-three lesions were categorized as nonproliferative and 151 as proliferative (94 had combined nonproliferative and proliferative histology). Follow-up ranged from 24 to 48 months (mean 33 months). During the follow-up period, 87 lesions (21.8%) underwent either image-guided or open biopsy. At the time of follow-up rebiopsy, ductal carcinoma in situ was found in four lesions and infiltrating ductal carcinoma was found in one, for an overall false-negative rate of 4.3% (5/117) and a negative predictive value of 98.8% (395/400). For the five false-negative cases, the interval from initial SCNB to definitive diagnosis ranged from 7 to 36 months. No correlation was found between the type of initial histopathology and development of malignancy., Conclusions: These results support SCNB as an alternative to open biopsy and show the reliability of SCNB when benign pathology is obtained. However, given the possibility of sampling error and the nature of breast disease, close mammographic and clinical follow-up is necessary. The false-negative rate and negative predictive value in this series compare favorably with those in other reports, supporting the fact that surgeons can confidently use SCNB in the evaluation and treatment of breast disease.

Background: Roquinimex (Linomide) is an immunotherapeutic agent used in conjunction with autologous bone marrow transplantation (ABMT) for treatment of acute and chronic myelogenous leukemia (AML and CML). This agent may induce graft-versus-host reactions (GVHR) as well as graft-versus-leukemia (GVL) effects., Objective: We documented the incidence of acute cutaneous GVHR associated with roquinimex immunotherapy. The presence or absence of autologous GVHR was also correlated with a potential GVL effect in patients with CML treated with ABMT and subsequent roquinimex immunotherapy in the period after the transplant., Methods: Fifteen patients undergoing bone marrow transplantation and roquinimex immunotherapy for CML were followed up, and clinicopathologic data were analyzed., Results: Acute cutaneous GVHRs were observed in 6 of 15 patients (40%) treated with roquinimex. Ten of 11 evaluable patients receiving roquinimex exhibited eccrine sweat gland necrosis (ESGN) (90.9%), which was independent of the acute GVHR. Neither bone marrow engraftment status nor the survival rates of patients with and without GVHR was significantly different., Conclusion: Roquinimex immunotherapy enhances the incidence of GVHR and was associated with a high rate of ESGN in patients with CML who were undergoing ABMT. There was no significant association between ESGN and acute GVHR. Acute autologous GVHR caused by roquinimex did not correlate with a GVL effect in our study of 15 patients with CML.

The human CD80 costimulatory molecule is an important signal between professional antigen-presenting cells and T helper cells. The immunobiology of CD80 expression by keratinocytes, especially during allergic and irritant contact dermatitis, however, is less well understood. CD80 cell surface expression and gene transcription by keratinocytes was increased when keratinocytes were exposed to certain allergens (chemicals that induce inflammation via hapten-specific T cells) and irritants (chemicals that are toxic to epidermal cells). Therefore, the human CD80 promoter was cloned and luciferase reporter constructs containing various promoter fragments were engineered. Promoter mapping of these CD80 constructs in transiently transfected keratinocytes showed that a construct containing the proximal 231 bp immediately upstream of the transcription start site of the CD80 promoter was most active in keratinocytes and was inducible to a level ranging from 2- to 10-fold higher in keratinocytes treated with certain allergens and irritants, compared with untreated keratinocytes. This pattern of promoter fragment activity in keratinocytes is identical to that found in professional antigen-presenting cells. This is the first demonstration that the CD80 promoter is active in keratinocytes and that this activity is further increased in keratinocytes treated with certain allergens and irritants. These data suggest that allergens and irritants may, in part, break peripheral tolerance by their direct effects on keratinocyte costimulatory molecule expression, thereby facilitating interactions with epidermotropic T helper cells via the CD80-CD28 or CTLA-4 pathways.

Purpose: The nontraditional clinical research rotation at the University of Tennessee College of Medicine-Chattanooga Unit is described and its efficacy evaluated by the number of peer-reviewed publications produced., Methods: In 1988, a mandatory year of clinical research was added to the general surgery curriculum. The year is completed in 3 4-month rotations, 1 each during the PGY-2, PGY-3, and PGY-4 years. Curriculum vitae of 31 graduates of the traditional 5-year residency were evaluated for publications produced during residency and 1 year beyond training. Comparison was made to 15 subjects; 8 were 6-year graduates and 7 were PGY-4, PGY-5, or PGY-6 residents having completed the research year. Statistical analysis used the Mann-Whitney U test for nonparametric data as well as an independent t test with significance set at 0.05. Publications were verified by a MEDLINE search. Six-year graduates also completed a questionnaire regarding their research experience., Results: Graduates of the 5-year program completed an average of 0.94 publications during residency, whereas 6-year graduates completed an average of 2.67 publications (p < 0.001). Opinions varied regarding desire to pursue research and the benefit of the research year., Conclusions: Our results demonstrate that basic science research is not the only model; academic productivity can be improved with an additional year devoted to clinical research. Advantages to this nontraditional approach include decreased likelihood of decline of clinical skills and knowledge, ability to maintain long-term projects, and a physical and mental break from a demanding clinical residency.

Background: Temporary abdominal wound closure after celiotomy for trauma is often desirable. The ideal method of temporary closure should allow rapid closure, easy maintenance, and allow reexploration and wound repair with minimal tissue damage. Over the past 7 years, we have successfully used a vacuum closure system (the vacuum pack) for temporary management of the open abdomen., Methods: Medical records of trauma patients undergoing exploratory celiotomy from April of 1992 to February of 1999 were reviewed. Demographic data as well as indications for open-abdominal management and complications of open-abdominal management were collected., Results: Two hundred sixteen vacuum packs were performed in 112 trauma patients. Of the 216 vacuum packs placed, 2.8% were placed for increased intra-abdominal pressure, 5.3% for inability to achieve tension-free fascial closure, 20% for damage control, 55% for reexploration, and 16.7% for a combination of factors. Sixty-two patients (55.4%) went on to primary closure and 25 patients (22.3%) underwent polyglactin mesh repair of the defect followed by wound granulation and eventual skin grafting. Twenty-two patients (19.6%) died before abdominal closure was attempted. Five patients (4.5%) developed enterocutaneous fistulae. Five patients (4.5%) developed intra-abdominal abscesses. There were no eviscerations. Three patients (2.7%) required further explorations after abdominal closure. Overall mortality rate was 25.9%, none related to the vacuum pack., Conclusions: The vacuum pack is the temporary abdominal wound closure of choice in patients undergoing open abdominal management at our institution. Primary closure is achieved in the majority of patients with a low rate of complication. The technique is simple and easily mastered. Technical complications are rare and easily repaired.

Imiquimod (R-837) and its more potent derivative (R-848) are imidazoquinolines that have adjuvant activity in cultured human mononuclear cells. Its mechanism of action on epidermal antigen-presenting cells is not known. The purpose of the present investigation was to determine whether imiquimod and R-848 affect human epidermal Langerhans' cells' (LC) in vitro maturation. Pulse incubations (6-16 h) of cultured unfractionated epidermal cells or highly enriched LC suspensions with either imiquimod or R-848 (0. 05-5.0 microg/ml of culture medium) reproducibly enhanced their ability to induce T-cell proliferation in a primary mixed lymphocyte reaction. There was a 30 to 300% increase in T-lymphocyte proliferation induced by either imiquimod- or R-848-treated LC when compared to control, untreated LC. IFN-gamma secretion by T-lymphocytes stimulated by imiquimod- or R-848-treated LC was increased compared to control, untreated LC. After a 6-h incubation, phenotypic analysis of control-, imiquimod-, or R-848-treated LC indicated that such antigen-presenting cells were in an "intermediate" state of maturation (CD1a(+), HLA-DR, DP, DQ(bright+), CD40(low+), CD86(high+), and CD80(low+)). RNase protection assays demonstrated that either imiquimod or R-848 treatments increased steady-state transcripts encoding for IL-12 p40, IL-1beta, TNF-alpha, and IL-1 receptor antagonist by LC. These data indicate that imiquimod and R-848 dissociate the functional maturation (cytokine-mediated) and phenotypic maturation of epidermal LC. These data warrant further exploration for the use of imidazoquinoline-treated LC or other DC subsets for processing and presentation of viral peptides to Th-lymphocytes as a novel vaccine strategy to induce protective antiviral responses., (Copyright 2000 Academic Press.)

Hyoid bone fractures secondary to blunt trauma other than strangulation are rare (ML Bagnoli et al., J Oral Maxillofac Surg 1988; 46: 326-8), accounting for only 0.002 per cent of all fractures. The world literature reports only 21 cases. Surgical intervention involves airway management, treatment of associated pharyngeal perforations, and management of painful symptomatology. The importance of hyoid fracture, however, rests not with the rarity of it, but with the lethal potential of missed diagnosis. We submit three cases with varying presentations and management strategies. All three of our cases incurred injury by blunt trauma to the anterior neck. Two patients required emergent surgical airway after unsuccessful attempts at endotracheal intubation. One patient presented without respiratory distress and was managed conservatively. After fracture, the occult compressive forces of hematoma formation and soft tissue swelling may compromise airway patency. It is our clinical observation that hypoxia develops rapidly and without warning, leading to cardiorespiratory collapse. With endotracheal intubation prohibited by obstruction, a surgical airway must be established and maintained. Recognition of subtle clinical and physical findings are critical to the diagnosis of laryngotracheal complex injuries and may be life-saving in many instances. To ensure a positive outcome, a strong degree of suspicion based on mechanism of injury is mandated.

The B7-1 (CD80) molecule provides costimulatory function for the activation of T helper lymphocytes upon encounter with antigen. To investigate the role of this molecule in thymocyte maturation, we have generated transgenic (Tg) mice in which CD80 expression is driven by the keratin 14 promoter (K14). This overexpression of CD80 resulted in the loss of detectable cell surface CD28 expression on thymocytes and a significant reduction in both the surface T cell receptor expression and the ratio of CD4(+) to CD8(+) single-positive thymocytes in Tg animals compared to nontransgenic (non-Tg) controls. While many of these defects were transient, the significant decrease in CD4(+) versus CD8(+) T cell ratio persisted peripherally. Peripheral T cells from these Tg mice were found to be significantly hyporesponsive to T cell mitogens and in mixed leukocyte reaction, effects that our data indicate are due to reduced IL-2 production by Tg T cells upon activation. Despite these functional defects, immunization with both complex and simple protein antigens produced no differences in the proliferative or humoral responses to these antigens between Tg and non-Tg groups. These data indicate that thymic CD80 signaling results in the deletion of significant numbers of CD4(+) T cells but does not culminate in antigen-specific immunodeficiency., (Copyright 1999 Academic Press.)

When thoracic aortic rupture is suspected, a 45-degree reverse Trendelenburg (RT) anteroposterior (AP) chest radiograph should place the mediastinal structures in a more appropriate position and allow a more accurate evaluation than a supine AP radiograph. One hundred ninety-one consecutive hemodynamically stable adult patients with major blunt thoracic trauma were initially evaluated for mediastinal abnormalities associated with aortic disruption by both supine AP chest radiograph and an AP chest radiograph with the patient in 45-degree RT position. One hundred four patients underwent contrast aortography based on mediastinal abnormalities detected on the supine AP chest radiograph. Twenty of these patients had abnormal aortograms demonstrating traumatic aortic disruption confirmed at surgery. Supine and RT chest radiographs were retrospectively compared in a blinded fashion to evaluate their specificity and positive predictive value for detection of traumatic thoracic aortic rupture. If RT chest radiographic findings had been used to determine the need for further assessment, 29 angiograms (26%) would have been eliminated, specificity would have increased from 52 per cent to 69 per cent, and positive predictive value would have increased from 19 per cent to 27 per cent. Both supine and RT chest radiographs demonstrated mediastinal widening in all 20 patients with abnormal aortograms, with no missed thoracic aortic disruptions (100% sensitivity). This study indicated that the RT chest radiograph may be used instead of the standard supine radiograph as the initial screen for mediastinal evaluation, maintaining a high sensitivity and eliminating the cost and morbidity of many unnecessary aortograms.

Background: Heavy ice and snow accumulation combined with record low temperatures in Chattanooga, Tennessee, from February 2-6, 1996, contributed to many sledding injuries., Methods: We retrospectively reviewed medical records of emergency visits to seven area hospitals from February 2-6, 1996. We further reviewed sledding injury records. Sledding was defined as sliding on snow or ice using any device except skis., Results: Of 2,134 emergency room visits, 241 patients had 310 sledding injuries. Ages of patients ranged from 3 to 53 years (mean, 18.9; median, 16). One hundred twenty-eight injuries were severe. These included extremity injuries (65), head injuries (28), chest injuries (10), intra-abdominal injuries (10), vertebral column fractures (11), and pelvic fractures (4). Thirty-six patients required inpatient hospitalization; 18 had surgery. The minimum healthcare costs associated with these injuries were estimated at $220,000., Conclusions: Major trauma potential is associated with sledding, especially where significant winter storms are uncommon. Level I trauma centers should seasonally incorporate sledding safety into community-wide injury prevention programs.

Primary aortoenteric fistulae (AEFs) are extremely rare vascular entities, with fewer than 250 cases reported in the world medical literature as of 1996. Incidence is less than 1 per cent, with a mortality ranging from 33 to 85 per cent. Atherosclerosis remains the most common etiology, accounting for more than two-thirds of the cases reported. Other etiologies include carcinoma, ulcers, gallstones, diverticulitis, appendicitis, and foreign bodies. Early diagnosis is crucial for survival and mandates recognition of the typical "herald bleed." Additional findings on initial presentation frequently include flank pain, abdominal pain, hematemesis, melena, and an abdominal mass. More than 80 per cent of primary AEFs involve the duodenum, with the overwhelming majority located in the third or fourth portion. Successful management of primary AEF requires a high index of suspicion for diagnosis and prompt surgical intervention for survival.

The endovascular treatment of peripheral arterial occlusive disease has historically been performed by interventional radiologists and cardiologists. With additional training in endovascular techniques, surgeons become uniquely suited to manage arterial lesions with both endovascular and conventional surgical techniques. Over a 14-month period, 13 patients underwent combination endovascular and open reconstruction on limbs with peripheral arterial occlusive disease. There were 10 males and 3 females. The mean age was 66 years. All procedures were performed in the operating room by surgery residents under the direct supervision of vascular surgeons. After intraoperative angiography, 26 arterial lesions underwent percutaneous transluminal angioplasty (aorta, 1; common iliac, 14; external iliac, 10; superficial femoral, 1). Twenty-five of 26 lesions were further treated with intraluminal stent placement, the lone exception being a case of superficial femoral artery angioplasty. Concomitant open reconstruction was performed on all limbs, 14 as outflow and 1 as inflow. There were two cases of procedural morbidity and one perioperative death secondary to myocardial infarction. There were no wound-related complications. The mean ankle-brachial index of the affected lower extremity improved from 0.41 (+/- 0.15) to 0.74 (+/- 0.14) at 30 days. Mean follow-up was 8 months (range, 2-14). Based on our early experience, simultaneous combination endovascular and open reconstruction of multisegment arterial occlusive disease can be performed safely and efficiently by surgeons.

Published data is controversial as to the ability of preoperative localization studies (PLS) to enhance the outcome of initial cervical exploration in patients with primary hyperparathyroidism (PHPT). One surgeon's experience was reviewed to compare surgical success, operative time, and morbidity of initial cervical exploration for PHPT in patients who had undergone PLS versus those who had not. From August 1991 to September 1997, 95 patients who had not undergone prior central cervical exploration presented for surgical management of PHPT. Sixty-seven patients underwent initial cervical exploration without any PLS having been performed (Group A). Twenty-eight patients underwent PLS, either alone or in combination, before surgical intervention (Group B). Analysis of intergroup variability was conducted upon the data available using a two-tailed t test for independent samples. In addition, the sensitivities and positive predictive values of the PLS were calculated using study reports and operative and histologic findings. There was no statistically significant difference in surgical success between those patients who had PLS and those that did not undergo PLS. Sixty-four of 67 patients (95.5%) not having PLS were cured with initial surgery, while 27 of 28 patients (96.4%) who had PLS were surgically cured. Mean postoperative calcium and intact parathormone levels were similar between the two groups, and the mean operative time did not differ. Permanent hypocalcemia occurred in one patient, and five patients had transient hoarseness. Thirty-six total PLS were obtained at an average cost of $752.68/patient, and seven patients underwent multiple tests. Overall, sestamibi scan had the highest positive predictive value (81%). For adenomatous disease alone, sestamibi scan was the most sensitive (83%). Our study shows that for matched groups limited to age, sex, and clinical diagnosis, the use of PLS did not shorten operative time, decrease complication frequency, nor alter the success of the operation as measured by postoperative calcium and parathormone levels. Therefore, routine use of preoperative localization studies before initial cervical exploration for PHPT cannot be recommended.

B7-1 (CD80) is a second signal molecule usually associated with "professional" APCs that prevents the induction of T-cell clonal anergy and induces IL-2 production during antigen presentation. Tg mice whose epidermal KC overexpress B7-1 exhibit exaggerated and persistent CHS to a variety of haptens that lasts up to 8 weeks after hapten challenge. These Tg mice also exhibit significantly enhanced ear-swelling responses to irritants that are not persistent. Exaggerated CHS was not reflected in the draining lymph node. T-lymphocyte proliferative responses after sensitization and local challenge with haptens, as there were no significant differences between the B7-1 Tg and the NTg mice. However, RT-PCR analysis of mouse ear skin at the hapten challenge site indicated that B7-1 Tg mice had an alteration in the kinetics of in situ lymphokine transcripts compared to NTg mice: IFN-gamma transcripts were first detectable in Tg mouse skin at 2 weeks versus 24 h for NTg mice. RNase protection assays to detect inflammatory cytokine transcripts at hapten application sites indicated that B7-1 Tg mice responded to hapten application with increased TNF-alpha, IL-6, and TNF-beta transcripts compared to NTg mice. Thus, hapten-induced ear swelling in these Tg mice may be mediated by enhanced inflammatory cytokines during the early phase (1-14 days). IFN-gamma-producing lymphocytes may be responsible for the late phase of the ear-swelling response (14-42 days). These data indicate that B7-1 overexpression by KC in mouse skin directly or indirectly affects the nature of cutaneous inflammation induced by haptens and irritants.

The influence of beta-chain diversity on the expressed T-cell receptor (TCR) alpha-chain repertoire was investigated using transgenic mice which exclusively express a single rearranged TCR beta-chain gene. Analysis of these mice using alpha-chain-specific recombinant cDNA libraries showed that expression of the transgene-encoded beta chain results in significant skewing in Tcra-V gene segment usage vs nontransgenic mice. Skewing was most pronounced towards alpha chains using TCRA-V segments. Sequence analysis of Tcra-V8-containing genes from transgenic T cells revealed predominant use of a single Tcra-J segment (Tcra-J24), which was not detected in Tcra-V8 containing genes isolated from nontransgenic T cells. Further analysis revealed that co-expression of Tcra-V8 with Tcra-J24 in beta-transgenic mice is exhibited almost exclusively by CD4+ T cells, and is associated with a limited number of closely related N-regions. Analysis of transgenic CD8+ T cells demonstrated predominant co-expression of Tcra-V8 with another Tcra-J (Tcra-J30), together with a different, limited N-region sequence. We conclude that the composition of expressed beta chains can profoundly influence the selection of companion alpha chains expressed in the periphery, and that alpha-chain N and J regions play a crucial role in discriminating between class I vs class II major histocompatibility complex (MHC)-restricted recognition. Further, these results are in agreement with recent data concerning the crystal structure of the TCR, and most consistent with a model for TCR structure in which the complementarity determining region (CDR)3alpha domain participates in direct contact with the MHC.

The purpose of this review is to present a 4-year experience with the vacuum pack technique of temporary abdominal closure. From April 1992 to December 1996, 171 vacuum packs were performed on 93 patients. Eighty-seven vacuum packs were performed on 38 general surgical patients, and 84 vacuum packs were performed on 55 trauma patients. Overall hospital mortality was 32 per cent. Methods of achieving permanent wound closure varied in 73 patients. Four patients (4.3%) developed enterocutaneous fistulae; four patients developed intra-abdominal abscesses (4.3%). There were no eviscerations. Management of the complicated intra-abdominal process is discussed: 1) the decision to manage the abdomen in an open fashion; 2) which method of temporary closure to use; 3) subsequent explorations; 4) when the abdomen should be closed; 5) which type of closure to use; and 6) when the abdominal wall should be revised (herniorrhaphy). The vacuum pack is the method of choice for open abdomen management and temporary abdominal closure at our institution. With careful subsequent management, good patient outcome can be achieved.

Background: The authors evaluated outcomes and treatment costs of stereotactic core needle biopsy (SCNB) and ultrasound core needle biopsy (UCNB), and needle localization biopsy (NLB) in managing patients with mammographic abnormalities presenting to the surgeon., Methods: Data for all patients with mammographic lesions who underwent SCNB or UCNB since their introduction at this institution were prospectively collected over 17 months. Mean inclusive costs of the three procedures were accumulated and compared., Results: Stereotactic core needle biopsy was performed for 342 lesions in 319 women, for a malignancy rate of 19%; UCNB was performed for 157 lesions in 144 patients, yielding a malignancy rate of 17%. With a mean follow-up of 13.5 months, 1 patient with in situ carcinoma was diagnosed late. Absolute cost savings for the period studied was $721,963., Conclusions: Minimally invasive breast biopsy procedures can safely and reliably be performed by surgeons in clinical practice with increased patient convenience and decreased costs.