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Background Delayed gastric emptying (DGE) occurs in up to 40% of patients after esophageal resection and prolongs recovery and hospital stay. Surgically pyloroplasty does not effectively prevent DGE. Recently published methods include injection of botulinum toxin (botox) in the pylorus and mechanical interventions as preoperative endoscopic dilatation of the pylorus. The aim of this study was to investigate the efficacy of those methods with respect to the newly published Consensus definition of DGE. Methods A systematic literature search using CENTRAL, Medline, and Web of Science was performed to identify studies that described pre- or intraoperative botox injection or mechanical stretching methods of the pylorus in patients undergoing esophageal resection. Frequency of DGE, anastomotic leakage rates, and length of hospital stay were analyzed. Outcome data were pooled as odd's ratio (OR) or mean difference using a random-effects model. Risk of bias was assessed using the Robins-I tool for non-randomized trials. Results Out of 391 articles seven retrospective studies described patients that underwent preventive botulinum toxin injection and four studies described preventive mechanical stretching of the pylorus. DGE was not affected by injection of botox (OR 0.87, 95% confidence interval [CI] 0.37–2.03, P  = 0.75), whereas mechanical stretching resulted in significant reduction of DGE (OR 0.26, 95% CI 0.14–0.5, P  < 0.0001). Conclusion Mechanical stretching of the pylorus, but not injection of botox reduces DGE after esophageal cancer resection. A newly developed consensus definition should be used before the conduction of a large-scale randomized-controlled trial. [ABSTRACT FROM AUTHOR]

Purpose: Gastric staple line leakage (GL) is a serious complication of laparoscopic sleeve gastrectomy (LSG), with a specific mortality ranging from 0.2 to 3.7%. The current treatment of choice is stent insertion. However, it is unclear whether the type of stent which is inserted affects treatment outcome. Therefore, we aimed not only to determine the effectiveness of stent treatment for GL but also to specifically clarify whether treatment outcome was dependent on the type of stent (small- (SS) or megastent (MS)) which was used. Patients and Methods: A single-centre retrospective study of 23 consecutive patients was conducted to compare the outcomes of SS (n = 12) and MS (n = 11) for the treatment of GL following LSG. The primary outcome measure was the success rate of stenting, defined as complete healing of the GL without changing the treatment strategy. Treatment change or death were both coded as failure. Results: The success rate of MS was 91% (10/11) compared to only 50% (6/12) for SS (p = 0.006). An average of 2.3 ± 0.5 and 6.8 ± 3.7 endoscopies were required to achieve healing in the MS and SS groups respectively (p < 0.001). The average time to resumption of oral nutrition was shorter in the MS group (1.4 ± 1.1 days vs. 23.1 ± 33.1 days, p = 0.003). Conclusions: Stent therapy is only effective and safe for the treatment of GL after LSG if a MS is used. Treatment with a MS may not only increase treatment success rates but may also facilitate earlier resumption of oral nutrition and shorten the duration of hospitalization. [ABSTRACT FROM AUTHOR]

Background: Anastomotic leakage (AL) in the upper gastrointestinal (GI) tract is associated with high morbidity and mortality rates. Especially intrathoracic anastomotic leakage leads to life-threatening complications. Endoscopic vacuum therapy (EVT) for anastomotic leakage after transthoracic esophageal resection represents a novel concept. However, sound clinical data are still scarce. This retrospective, single-center study aimed to evaluate the feasibility, effectiveness, and safety of EVT for intrathoracic anastomotic leakage following abdomino-thoracic esophageal resection. Methods: From March 2014 to September 2019 259 consecutive patients underwent elective transthoracic esophageal resection. 72 patients (27.8%) suffered from AL. The overall collective in-hospital mortality rate was 3.9% (n = 10). Data from those who underwent treatment with EVT were included. Results: Fifty-five patients were treated with EVT. Successful closure was achieved in 89.1% (n = 49) by EVT only. The EVT-associated complication rate was 5.4% (n = 3): bleeding occurred in one patient, while minor sedation-related complications were observed in two patients. The median number of EVT procedures per patient was 3. The procedures were performed at intervals of 3–5 days, with a 14-day median duration of therapy. The mortality rate of patients with AL was 7.2% (n = 4). Despite successfully terminated EVT, three patients died because of multiple organ failure, acute respiratory distress syndrome, and urosepsis (5.4%). One patient (1.8%) died during EVT due to cardiac arrest. Conclusions: EVT is a safe and effective approach for intrathoracic anastomotic leakages following abdomino-thoracic esophageal resections. It offers a high leakage-closure rate and the potential to lower leakage-related mortalities. Trial registration: This trial was registered and approved by the Institutional Ethics Committee of the University of Heidelberg on 16.04.2014 (Registration Number: S-635/2013). [ABSTRACT FROM AUTHOR]

Background: Anastomotic leakage (AL) in the upper gastrointestinal (GI) tract is associated with high morbidity and mortality rates. Especially intrathoracic anastomotic leakage leads to life-threatening complications. Endoscopic vacuum therapy (EVT) for anastomotic leakage after transthoracic esophageal resection represents a novel concept. However, sound clinical data are still scarce. This retrospective, single-center study aimed to evaluate the feasibility, effectiveness, and safety of EVT for intrathoracic anastomotic leakage following abdomino-thoracic esophageal resection.Methods: From March 2014 to September 2019 259 consecutive patients underwent elective transthoracic esophageal resection. 72 patients (27.8%) suffered from AL. The overall collective in-hospital mortality rate was 3.9% (n = 10). Data from those who underwent treatment with EVT were included.Results: Fifty-five patients were treated with EVT. Successful closure was achieved in 89.1% (n = 49) by EVT only. The EVT-associated complication rate was 5.4% (n = 3): bleeding occurred in one patient, while minor sedation-related complications were observed in two patients. The median number of EVT procedures per patient was 3. The procedures were performed at intervals of 3-5 days, with a 14-day median duration of therapy. The mortality rate of patients with AL was 7.2% (n = 4). Despite successfully terminated EVT, three patients died because of multiple organ failure, acute respiratory distress syndrome, and urosepsis (5.4%). One patient (1.8%) died during EVT due to cardiac arrest.Conclusions: EVT is a safe and effective approach for intrathoracic anastomotic leakages following abdomino-thoracic esophageal resections. It offers a high leakage-closure rate and the potential to lower leakage-related mortalities.Trial Registration: This trial was registered and approved by the Institutional Ethics Committee of the University of Heidelberg on 16.04.2014 (Registration Number: S-635/2013). [ABSTRACT FROM AUTHOR]

Background: Anastomotic leakage (AL) in the upper gastrointestinal (GI) tract is associated with high morbidity and mortality rates. Especially intrathoracic anastomotic leakage leads to life-threatening complications. Endoscopic vacuum therapy (EVT) for anastomotic leakage after transthoracic esophageal resection represents a novel concept. However, sound clinical data are still scarce. This retrospective, single-center study aimed to evaluate the feasibility, effectiveness, and safety of EVT for intrathoracic anastomotic leakage following abdomino-thoracic esophageal resection. Methods: From March 2014 to September 2019 259 consecutive patients underwent elective transthoracic esophageal resection. 72 patients (27.8%) suffered from AL. The overall collective in-hospital mortality rate was 3.9% (n = 10). Data from those who underwent treatment with EVT were included. Results: Fifty-five patients were treated with EVT. Successful closure was achieved in 89.1% (n = 49) by EVT only. The EVT-associated complication rate was 5.4% (n = 3): bleeding occurred in one patient, while minor sedation-related complications were observed in two patients. The median number of EVT procedures per patient was 3. The procedures were performed at intervals of 3–5 days, with a 14-day median duration of therapy. The mortality rate of patients with AL was 7.2% (n = 4). Despite successfully terminated EVT, three patients died because of multiple organ failure, acute respiratory distress syndrome, and urosepsis (5.4%). One patient (1.8%) died during EVT due to cardiac arrest. Conclusions: EVT is a safe and effective approach for intrathoracic anastomotic leakages following abdomino-thoracic esophageal resections. It offers a high leakage-closure rate and the potential to lower leakage-related mortalities. Trial registration: This trial was registered and approved by the Institutional Ethics Committee of the University of Heidelberg on 16.04.2014 (Registration Number: S-635/2013). [ABSTRACT FROM AUTHOR]

Background: Early diagnosis of anastomotic leakage (AL) after esophageal resection is crucial for the successful management of this complication. Inflammatory serological markers are indicators of complications during the postoperative course. The aim of the present study was to evaluate the prognostic value of routine inflammatory markers to predict anastomotic leakage after transthoracic esophageal resection.Methods: Data from all consecutive patients undergoing transthoracic esophageal resection between January 2010 and December 2016 were analyzed from a prospective database. Besides clinicodemographic parameters, C-reactive protein, white blood cell count and albumin were analyzed and the Noble/Underwood (NUn) score was calculated to evaluate their predictive value for postoperative anastomotic leakage. Diagnostic accuracy was measured by sensitivity, specificity, and negative and positive predictive values using area under the receiver operator characteristics curve.Results: Overall, 233 patients with transthoracic esophageal resection were analyzed, 30-day mortality in this group was 3.4%. 57 patients (24.5%) suffered from AL, 176 patients were in the AL negative group. We found significant differences in WBCC, CRP and NUn scores between patients with and without AL, but the analyzed markers did not show an independent relevant prognostic value. For CRP levels below 155 mg/dl from POD3 to POD 7 the negative predictive value for absence of AI was > 80%. Highest diagnostic accuracy was detected for CRP levels on 4th POD with a cut-off value of 145 mg/l reaching negative predictive value of 87%.Conclusions: In contrast to their prognostic value in other surgical procedures, CRP, WBCC and NUn score cannot be recommended as independent markers for the prediction of anastomotic leakage after transthoracic esophageal resection. CRP is an accurate negative predictive marker and discrimination of AL and no-AL may be helpful for postoperative clinical management. Trial registration The study was approved by the local ethical committee (S635-2013). [ABSTRACT FROM AUTHOR]

Background: Patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) require adequate sedation or general anesthesia. To date, there is lack of consensus regarding who should administer sedation in these patients. Several studies have investigated the safety and efficacy of non-anesthesiologist-administered sedation for ERCP; however, data regarding anesthesiologist-administered sedation remain limited. This prospective single-center study investigated the safety and efficacy of anesthesiologist-administered sedation and the rate of successful performed ERCP procedures. Methods: The study included 200 patients who underwent ERCP following anesthesiologist-administered sedation with propofol and remifentanil. Procedural data, oxygen saturation, systolic blood pressure (SBP), heart rate, recovery score, patient and endoscopist satisfaction, as well as 30-day mortality and morbidity data were analyzed. Results: Sedation-related complications occurred in 36 of 200 patients (18%) and included hypotension (SBP < 90 mmHg) and hypoxemia (O2 saturation < 90%) in 18 patients (9%) each. Most events were minor and did not necessitate discontinuation of the procedure. However, ERCP was terminated in 2 patients (1%) secondary to sedation-related complications. Successful cannulation was performed in all patients. The mean duration of the examination was 25 ± 16 min. Mean recovery time was 14 ± 10 min, and high post-procedural satisfaction was observed in both, patients (mean visual analogue scale [VAS] 9.6 ± 0.8) and endoscopists (mean VAS 9.3 ± 1.3). Conclusion: This study suggests that anesthesiologist-administered sedation is safe in patients undergoing ERCP and is associated with a high rate of successful ERCP, shorter procedure time, and more rapid post-anesthesia recovery, with high patient and endoscopist satisfaction. [ABSTRACT FROM AUTHOR]

Purpose: Anastomotic leakage is the most frequent cause of postoperative mortality following esophageal surgery. However, no gold standard for diagnosing and managing leakage has been established. Continuous clinical judgment is extremely important; therefore, to optimize the management of leakage, we established a special group for decision-making in cases of suspected leakage in the early postoperative period. Methods: Between January 2010 and December 2016, 234 consecutive patients underwent elective esophageal resection with a thoracoabdominal incision. In 2014, we established a group consisting of a surgeon, surgical endoscopist, and anesthesiologist for decision-making in cases of suspected leakage. They discussed emerging problems and decided on further diagnostics or therapy. The data were documented prospectively and compared to the years prior to 2014. Results: Two hundred and thirty-four consecutive patients were enrolled in the study, 110 in the years 2010-2013 (group A), and 124 in the years 2014-2016 (group B). Neither patients' characteristics nor the rate of anastomotic leakage differed significantly between the two study groups. The hospital mortality rate was 10% (11 patients) in group A and 4.8% (six patients) in group B. Most interestingly, mortality due to anastomotic leakage was 35% in group A (9/26), whereas it decreased significantly to 6.5% (2/31 patients) ( P < 0.001) in group B. Conclusions: Our data clearly demonstrated that optimizing the management of anastomotic leakage by making team decisions can lead to a significant decrease in mortality. [ABSTRACT FROM AUTHOR]

Background and study aims Extensive endoscopic mucosal resection (EMR) for Barrett's esophagus (BE) may lead to stenosis. Laparoscopic, transgastric, stapler-assisted mucosectomy (SAM) with the retrieval of a circumferential specimen is proposed. Methods SAM was evaluated in two phases. The feasibility of SAM and the quality of specimens were assessed in eight animals. The mucosal healing was evaluated in a 6-week survival experiment comparing SAM (n = 6) with EMR (n = 6). The ratio of the esophageal lumen width (REL) at the resection level measured on fluoroscopy at 6 weeks divided by the width immediately after resection was compared. Results In all animals, a circular mucosectomy specimen was successfully obtained, with a median area of 492 mm2 (interquartile range [IQR] 426 - 573 mm2) and 941 mm2 (IQR 813 - 1209 mm2) using a 21 mm and 25 mm stapler, respectively. In the survival experiments, symptomatic stenosis developed in two animals after EMR and in none after SAM. The REL was 0.27 (0.18 - 0.39) and 0.96 (0.9 - 1.04; P < 0.0001) for EMR and SAM, respectively. Conclusions SAM provides a novel technique for en bloc mucosectomy in BE. In contrast to EMR, mucosal healing after SAM was not associated with stenosis up to 6 weeks after intervention. [ABSTRACT FROM AUTHOR]

Background: Bile leaks after hepatic resection are serious complications associated with substantial morbidity and mortality. The aim of this prospective observational study was to determine the therapeutic success of endoscopic treatment of biliary leakage after liver resection.Patients and Methods: Grade B biliary leaks were considered for endoscopic treatment in patients after liver resection between 1/09 and 4/12. Endoscopic treatment (sphincterotomy only, plastic stent distal to leak or bridging) was defined as successful when the patient remained without symptoms after drain removal and without extravasation follow-up ERC 8 weeks later.Results: Overall rate of biliary leak was 7.4 % (61/826). 35 patients with a grade B bile leak were considered for endoscopic treatment. 22 (63 %) had bile leaks that were peripherally located, and 13 (37 %) had bile leaks at central location. In 3 patients, sphincterotomy only was performed; in 19 patients, a stent distal to the leak and in 13 patients, a bridging stent was inserted. The overall success rate was 74 % (26/35 patients). Endoscopic treatment failed in 26 % (9/35), and mortality rate was 11 % (4/35). In all patients with leaks located at the right or left hepatic duct, treatment with the bridging stent was successful.Conclusion: Endoscopic therapy for biliary leakage after liver resection is safe and effective and should be considered as a first-line therapy in patients who are suitable for an interventional, non-surgical approach. Patients with a centrally located leak who are treated with a bridging stent are more likely to benefit from endoscopic intervention. [ABSTRACT FROM AUTHOR]

Purpose: After esophageal surgery, many centers conduct a routine diagnostic test before reintroducing oral intake. However, the clinical value in asymptomatic patients has been questioned. Therefore, we left this decision to the discretion of the operating surgeon and documented the data prospectively. Methods: Between 2007 and 2013, 185 consecutive patients underwent elective esophageal resection in our institution. The decision as to whether an endoscopy was to be performed as a routine-check or when a leak was clinically suspected was at the discretion of the operating surgeon. An immediate endoscopy was performed on emerging clinical signs of a leak. If a routine check was planned, it was performed between postoperative days 5-7. Results: Of the 185 patients, 84 % had an endoscopy of the anastomosis during the hospital stay. Of the patients who underwent an endoscopy, 61 % were on a routine-check. In this group, one patient showed a leak at the time of endoscopy, 11 patients had pathological findings, 3 of these patients developed a leak later. Eighty-three patients had no pathological findings; nevertheless, 7 developed a leak later. In the on-demand-group, 10 patients showed a leak at the time of endoscopy. Conclusions: In a minority of patients, a routine-check of the anastomosis between days 5-7 revealed pathological findings that later led to an anastomotic leak (3/11). In contrast, a routine-check without pathological findings could not rule out the development of a future leak (7/83). Therefore, we conclude that routine postoperative studies to identify leaks after esophageal resection are not justified. [ABSTRACT FROM AUTHOR]

Background: Sedation prior to esophagogastroduodenoscopy is widespread and increases patient comfort. However, it demands additional trained personnel, accounts for up to 40 % of total endoscopy costs and impedes rapid hospital discharge. Most patients lose at least one day of work. 98 % of all serious adverse events occurring during esophagogastroduodenoscopy are ascribed to sedation. Acupuncture is reported to be effective as a supportive intervention for gastrointestinal endoscopy, similar to conventional premedication. We investigated whether acupuncture during elective diagnostic esophagogastroduodenoscopy could increase the comfort of patients refusing systemic sedation.Methods: We performed a single-center, double-blinded, placebo-controlled superiority trial to compare the success rates of elective diagnostic esophagogastroduodenoscopies using real and placebo acupuncture. All patients aged 18 years or older scheduled for elective, diagnostic esophagogastroduodenoscopy who refused systemic sedation were eligible; 354 patients were randomized. The primary endpoint measure was the rate of successful esophagogastroduodenoscopies. The intervention was real or placebo acupuncture before and during esophagogastroduodenoscopy. Successful esophagogastroduodenoscopy was based on a composite score of patient satisfaction with the procedure on a Likert scale as well as quality of examination, as assessed by the examiner.Results: From February 2010 to July 2012, 678 patients were screened; 354 were included in the study. Baseline characteristics of the two groups showed a similar distribution in all but one parameter: more current smokers were allocated to the placebo group. The intention-to-treat analysis included 177 randomized patients in each group. Endoscopy could successfully be performed in 130 patients (73.5 %) in the real acupuncture group and 129 patients (72.9 %) in the placebo group. Willingness to repeat the procedure under the same conditions was 86.9 % in the real acupuncture group and 87.6 % in the placebo acupuncture group.Conclusions: Esophagogastroduodenoscopy without sedation is safe and can successfully be performed in two-thirds of patients. Patients planned for elective esophagogastroduodenoscopy without sedation do not benefit from acupuncture of the Sinarteria respondens (Rs) 24 Chengjiang middle line, Pericard (Pc) 6 Neiguan bilateral, or Dickdarm (IC) 4 Hegu bilateral, according to traditional Chinese medicine meridian theory.Trial Registration: DRKS00000164 . Registered on 10 December 2009. [ABSTRACT FROM AUTHOR]

To the Editor: We would like to thank Sánchez-Luna et al. for their comments on our article "Endoscopic Stent Placement can successfully treat Gastric Leak following Laparoscopic Sleeve Gastrectomy If and Only If an Esophagoduodenal Megastent is used" [[1]]. Considering that alternative treatments such as EndoVac and others require regular endoscopic interventions, endoscopic stent repositioning in 30% of patients is an acceptable outcome, especially when the success rate of that therapy is so high (> 90%). [Extracted from the article]

Background: The high incidence of cholesterol gallstones in patients after proctocolectomy with ileal pouch-anal anastomosis (IPAA) may be due to an increased loss of bile acids. We aimed to evaluate the kinetics of the primary bile acids cholic acid (CA) and chenodeoxycholic acid (CDCA) in these patients. Methods: Pool sizes, synthesis rates, and fractional turnover rates of CA and CDCA were determined by combined capillary gas chromatography/isotope ratio mass spectrometry in serum samples after administration of [13C]CA and [13C]CDCA in 6 patients and 9 healthy volunteers. Results: In patients with IPAA, pool sizes of CA and CDCA were 11.5 (8.2-23.8) and 12.1 (6.7-20.1) µmol/kg, respectively, and were significantly lower than in healthy controls [36.0 (24-47) and 29.0 (21-42) µmol/kg, respectively; p < 0.05, each]. Fractional turnover rates of CA [1.19 (1.06-1.82) vs. 0.31 (0.13-0.54) per day] and CDCA [1.01 (0.50-1.63) vs. 0.23 (0.09-0.36) per day] were increased fourfold in patients with IPAA (p < 0.05, each). Synthesis rates of CDCA [10.2 (5.2-32.9) vs. 6.6 (2.7-10.5) µmol/kg per day, p = 0.05] and CA [15.1 (9.3-39.4) vs. 11.5 (3.1-20.5) µmol/kg per day, n.s.] tended to be higher in patients with IPAA than in controls. Conclusion: The reduced pool size of primary bile acids may contribute to the high incidence of cholesterol gallstones in patients after proctocolectomy and IPAA. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: Anastomotic leakage is a major complication in esophageal surgery. Although contrast swallow is performed by many surgical centers before reintroduction of oral intake to exclude anastomotic leakage postoperatively, endoscopy is increasingly used in this situation and may be superior. This study compares radiographic contrast study and endoscopy for the identification of local complications after subtotal esophagectomy. Methods: Between January 2006 and September 2007, a prospective, blinded, intraindividually controlled study was conducted in patients who underwent transthoracic esophagectomy due to esophageal cancer. A radiographic contrast study was performed prior to endoscopy on postoperative day 5-7. Technical feasibility, sensitivity, and specificity of the radiologic and endoscopic evaluations of the esophageal substitute were described. Results: Radiographic contrast study was possible in only 64 % of the patients (35 of 55). The contrast study could not be performed in 20 patients due to contraindications or mechanical ventilation. Endoscopy could be performed in all patients ( p < 0.001). Pathologic findings were detected in 13 patients by endoscopy but in only 1 patient by contrast swallow. Leakage of the anastomosis or the conduit was correctly detected in 7 patients by endoscopy but in only 1 patient by contrast swallow ( p = 0.01). Endoscopy detected focal conduit necrosis or ischemia in six additional patients. Contrast studies showed false-positive results in two patients. Both sensitivity and specificity of endoscopy were 100 %, while sensitivity and specificity of the contrast study were only 20 and 94 %. No complications resulted from postoperative endoscopy or radiologic imaging. Conclusions: Endoscopic evaluation of the esophageal substitute in the early postoperative course is possible in all patients without complications. Endoscopy is superior to the contrast study in detecting pathological findings after esophageal reconstruction. Radiologic contrast swallow in the early postoperative days is often not possible, has no further relevance, and should be replaced by endoscopic evaluation. [ABSTRACT FROM AUTHOR]

Aims The small molecule indirubin-3′-monoxime (I3MO) has been shown to inhibit vascular smooth muscle cell (VSMC) proliferation and neointima formation in vivo. The influence of I3MO on VSMC migration and vascular inflammation, two additional key players during the onset of atherosclerosis and restenosis, should be investigated. Methods and results We examined the influence of I3MO on VSMC migration, with focus on monocyte-derived leukotrienes (LTs) and platelet-derived growth factors (PDGFs) as elicitors. Exogenous LTB4 and cysteinyl leukotrienes as well as LT-enriched conditioned medium of activated primary human monocytes induced VSMC migration, which was inhibited by I3MO. I3MO also blunted migration of VSMC stimulated with the PDGF, the strongest motogen tested in this study. Induction of haem oxygenase 1 accounted for this anti-migratory activity of I3MO in VSMC. Notably, I3MO not only interfered with the migratory response in VSMC, but also suppressed the production of pro-migratory LT in monocytes. Conditioned media from monocytes that were activated in the presence of I3MO failed to induce VSMC migration. In cell-based and cell-free assays, I3MO selectively inhibited 5-lipoxygenase (5-LO), the key enzyme in LT biosynthesis, with an IC50 in the low micromolar range. Conclusion Our study reveals a novel dual inhibitory mode of I3MO on LT-mediated VSMC migration: (i) I3MO interferes with pro-migratory signalling in VSMC and (ii) I3MO suppresses LT biosynthesis in monocytes by direct inhibition of 5-LO. These inhibitory actions on both migratory stimulus and response complement the previously demonstrated anti-proliferative properties of I3MO and may further promote I3MO as promising vasoprotective compound. [ABSTRACT FROM AUTHOR]

Background: Navigation systems potentially facilitate minimally invasive esophagectomy and improve patient outcome by improving intraoperative orientation, position estimation of instruments, and identification of lymph nodes and resection margins. The authors' self-developed navigation system is highly accurate in static environments. This study aimed to test the overall accuracy of the navigation system in a realistic operating room scenario and to identify the different sources of error altering accuracy. Methods: To simulate a realistic environment, a porcine model ( n = 5) was used with endoscopic clips in the esophagus as navigation targets. Computed tomography imaging was followed by image segmentation and target definition with the medical imaging interaction toolkit software. Optical tracking was used for registration and localization of animals and navigation instruments. Intraoperatively, the instrument was displayed relative to segmented organs in real time. The target registration error (TRE) of the navigation system was defined as the distance between the target and the navigation instrument tip. The TRE was measured on skin targets with the animal in the 0° supine and 25° anti-Trendelenburg position and on the esophagus during laparoscopic transhiatal preparation. Results: On skin targets, the TRE was significantly higher in the 25° position, at 14.6 ± 2.7 mm, compared with the 0° position, at 3.2 ± 1.3 mm. The TRE on the esophagus was 11.2 ± 2.4 mm. The main source of error was soft tissue deformation caused by intraoperative positioning, pneumoperitoneum, surgical manipulation, and tissue dissection. Conclusion: The navigation system obtained acceptable accuracy with a minimally invasive transhiatal approach to the esophagus in a realistic experimental model. Thus the system has the potential to improve intraoperative orientation, identification of lymph nodes and adequate resection margins, and visualization of risk structures. Compensation methods for soft tissue deformation may lead to an even more accurate navigation system in the future. [ABSTRACT FROM AUTHOR]

Purpose: The usefulness and prognostic impact of a pretherapeutic clinical staging is still a matter of discussion. However, a pretherapeutic estimation of the prognosis would be essential to adjust the patient's therapy. Our aim was to compare clinical and histopathological staging and to analyze the predictive value of routine clinical staging and its significance for the individualization of treatment. Patients and methods: We analyzed the data of 368 patients treated with gastric cancer in the University of Heidelberg, Department of Surgery, from January 2001 to June 2009. Pretherapeutic parameters including sex, age, cTNM, grading, Laurén classification, tumor localization, as well as posttherapeutic parameters were analyzed, and their impact for survival was evaluated. Follow-up data was obtained for all patients (2.17% lost to follow-up). Results: The overall accuracy was 64.1% for pT category, 54.5% for pN category, and 80.3% for M category for the primary resected patients. For the patients treated neoadjuvantly, the overall accuracy was 21.8% for the pT category, 58.0% for the pN category, and 80.0% for the M category. The prognosis was associated to the age ( p = 0.017), tumor localization ( p < 0.001), grading ( p = 0.041), cT category ( p < 0.001), cN category ( p < 0.001), and cM category ( p = 0.001). The multivariate analysis, including pre- and postoperative factors, revealed tumor localization ( p = 0.002), cN category ( p = 0.019), and metastatic lymph node rate ( p < 0.001) as independent prognostic factors. Conclusion: The accordance between clinical and histopathological staging is limited, but nevertheless pretherapeutic parameters have a high prognostic impact and could be used for individualized therapy planning. The relevant pretherapeutic prognostic factors can all be determined by routine clinical staging including CT and endoscopy. Consequently pretherapeutic prognostic evaluation and therapy planning seem to be feasible with routine staging methods. [ABSTRACT FROM AUTHOR]