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KEY MESSAGE Knowledge of the changes that occur in the abdominal wall after component separation (CS) is essential for understanding the mechanisms of action of the various CS techniques, the changes observed on computed tomography images, and, perhaps most importantly, the anatomic and physiologic changes observed in patients who have undergone CS. Purpose Component separation (CS) techniques are essential adjuncts during most abdominal wall reconstructions. They allow the fulfillment of most modern abdominal wall reconstruction principles, especially primary closure of defects and linea alba restoration under physiologic tension. Knowledge of the post-CS abdominal wall changes is essential to understanding the mechanism of action of the various types of CS, the changes observed on computed tomographic images, and, perhaps most importantly, the anatomic and physiologic changes following CS techniques. Methods A systematic review of the literature was conducted using the PubMed database and other sources to identify articles describing abdominal wall changes after CS Results After excluding non-pertinent articles, 14 articles constituted the basis for this review. Conclusions After reviewing the literature on post CS abdominal wall changes, we conclude the following: (1)The external oblique muscle is significantly displaced laterally after anterior CS, the transversus abdominis muscle shifts very little after posterior CS, and muscle trophism is generally maintained after both techniques. These findings are consistent for both open and minimally invasive CS. (2) The anatomy and physiology of abdominal wall muscles are preserved mainly by the muscles' overlapping function and their ability to undergo compensatory trophism after midline restoration (reloading). (3) Well-performed CS techniques have a low risk of producing bulging and semilunar line hernias. (4) Anterior and posterior CS techniques probably have different mechanisms of action. (5) Current studies on how the nutritional status and postoperative conditioning can alter abdominal wall changes after CS and the mechanisms of the actions involved in anterior and posterior CS are underway.

Component separation (CS) procedures have become an important part of surgeons’ armamentarium. However, the exact criteria for training, procedure/mesh choice, as well as patient selection for CS remains undefined. Herein we aimed to identify trends in CS utilization between various cohorts of practicing surgeons. Members of the Americas Hernia Society were queried using an online survey. Responders were stratified according to their experience, practice profile (private vs academic, general vs hernia surgery), and volume (low (

Purpose Over the last years, great advances in the repair of abdominal wall hernias have dramatically improved patients' outcomes. Especially for large and other complex ventral hernias, the application of component separation techniques has been a landmark in their successful management. The aim of this study is to present our experience with the posterior component separation with transversus abdominis release (TAR) in patients with these demanding ventral hernias. Methods A retrospective analysis of prospectively collected data of all patients who underwent elective ventral hernia repair with TAR between January 2016 and December 2019 was performed. Preoperative, intraoperative, and postoperative data were analyzed. Results A total of 125 patients with large and other complex ventral hernias were included in the final analysis. More than 80% of patients had one or more comorbidities. Of all patients, 116 (92.8%) had a history of previous abdominal surgery, 27 (21.6%) had a history of SSI and nine (7.2%) had active fistulas. Postoperatively, SSOs were presented in 11 patients (8.8%), including three cases of SSI. Neither mesh infection occurred, nor mesh excision required. With a mean follow-up of 2.5 years, only one recurrence was observed. Conclusions With a wound complication rate of less than 9% and a recurrence rate of less than 1%, our results show that TAR is a reliable, safe and effective technique for the repair of massive and other complex ventral hernias. The combination of knowledge of the abdominal wall anatomy at a proficient level, proper training, and adoption of a strict prehabilitation program are considered prerequisites for the successful management of such demanding hernias.

PURPOSE The laparoscopic ventral hernia repair (LVHR) may have a limit of effectiveness, especially in defects greater than 80 cm2, with a higher recurrence rate which contraindicates this technique. The purpose of this study is to analyze the indication of LVHR determining and comparing the recurrence rate according to defect size in two series. METHODS We analyzed all patients who underwent LVHR between 2007 and 2017. Patients were divided according to the ring size

Posterior component separation with transversus abdominis release is a new procedure and is quickly gaining popularity. It has shown promising results in terms of low recurrence rates for large and complex hernias. However, there are very little Indian data available on this to date. The purpose of this study was to assess the outcomes of the technique at three centers in India. This was a retrospective analysis of the prospectively collected data. Patients with a minimum follow-up of 3 months who underwent open or minimal access posterior component separation were included. A total of 72 patients (open = 44, minimal access = 25, and hybrid = 3) were included in the analysis. At a follow-up ranging from 3 months to 35 months, there were two recurrences (2.78%). Surgical site occurrences were seen in 23/72 (31.9%), and surgical site infection was seen in 7/72 (9.7%). Surgical site occurrence requiring procedural intervention was 3/72 (4.2%). There were two (2.78%) mortalities in the open group due to myocardial infarction. Posterior component separation with transversus abdominis release may have advantages in terms of low recurrence in large hernias in the Indian population and can be used in carefully selected patients.

Repair of loss of domain hernia (LODH) has many related postoperative complications and abdominal separation techniques are well-accepted methods for avoiding abdominal compartment syndrome. The purpose of our study was to evaluate the effectiveness of anterior component separation technique and method of the patient selection for this technique in LODH. Between 2016 and 2019, 40 consecutive patients operated for LODH with over 10-cm fascial defect were analyzed prospectively. Patients were divided into two groups according to the hernia volume/abdominal volume ratio. Group 1 included patients less than 0.25 ratio and group 2 over 0.25. Bladder pressure, length of hospital stay, pain, bleeding, wound infection, and the duration of drainage tube were compared between groups. Average operation time, hospital stay, and wound drainage time was similar in both groups. In group 1, postoperative intra-abdominal hypertension was detected in 5 patients, whereas there was none in group 2. The rating of the individual measurement and sum of the defects will give proper results in multiple hernia defects. The properly performed anterior component separation alone would be an effective method on patients with LODH in order to avoid abdominal compartment syndrome.

Component separation remains an integral step during ventral hernia repair. Although a multitude of techniques are described, anterior component separation (ACS) via external oblique release (EOR) and posterior component separation (PCS) via transversus abdominis muscle release (TAR) are commonly utilized. The extent of myofascial medialization after ACS or PCS has not been well elucidated. We conducted a comparative analysis of ACS versus PCS in an established cadaveric model. Fifteen cadavers underwent both ACS via EOR and PCS via TAR. Following midline laparotomy (MLL), baseline myofascial elasticity was measured. Steps for ACS included creation of subcutaneous flaps (SQF), external oblique release (EOR), and retrorectus dissection (RRD). For PCS, steps included retrorectus dissection (RRD), transversus abdominis muscle division (TAD), and retromuscular dissection (RMD). Maximal advancement of anterior rectus fascia (ARF) was measured following application of tension to the fascia as a whole, and separately at upper, middle, and lower segments. Statistical analysis was performed with Mann–Whitney U test. Values are represented as average myofascial medialization in centimeters. Following MLL an average of 5.0 ± 0.9 cm (range 3.4–6.0 cm) of baseline medialization was obtained. Complete ACS provided 8.8 ± 1.2 cm (range 6.3–10.7 cm) of ARF advancement compared to 10.2 ± 1.7 cm (range 7.6–12.7 cm) with PCS, p = 0.046. In the upper and mid-abdomen, we noted increased ARF advancement with PCS versus ACS (8.1 ± 1.4 cm vs. 6.7 ± 1.2 cm and 11.4 ± 1.5 vs. 9.6 ± 1.4 cm, respectively, p = 0.01). Similar levels of ARF advancement were observed in the lower abdomen, 9.1 ± 1.7 cm versus 8.7 ± 1.8 cm, p = 0.535. Component separation via both anterior and posterior approaches provide substantial myofascial advancement. In our model, we noted statistically greater anterior fascial medialization after PCS versus ACS as a whole, and especially in the upper and mid-abdomen. We advocate PCS as a reliable and possibly superior alternative for linea alba restoration for reconstructive repairs, especially for large defects in the upper and mid-abdomen.

BMI and hernia defect size are strongly associated with outcomes after open ventral hernia repair (OVHR). The impact of abdominal subcutaneous fat (SQV), intra-abdominal volume (IAV), hernia volume (HV), and ratio of HV to intra-abdominal volume (HV:IAV, representing visceral eventration) is less clearly elucidated. This study examines the interaction of multiple markers of adiposity and hernia size in OVHR. OVHR with preoperative CT scans were identified. 3D volumetric software measured HV, SQV, IAV, and HV:IAV was calculated. A principal component analysis was performed to create new component variables for collinear variables. Hernia PC was composed primarily of hernia dimensions, EAV (extra-abdominal volume PC) included SQV and BMI, and IAV PC included IAV. A total of 1178 OVHR patients had a preoperative CT scan. Their demographics included a mean age of 58.5 ± 12.4 years, BMI of 34.2 ± 7.7 kg/m2, and 57.8% were female. The mean defect area was 150.8 ± 136.7 cm2, and 66.0% were recurrent, Patients had mean SQV of 6719.4 ± 3563.9 cm3, HV of 966.9 ± 1303.5 cm3, IAV of 4250.2 ± 2118.1 cm3, and a HV:IAV of 0.29 ± 0.46. In multivariate analysis, Hernia PC was associated with panniculectomy (OR 1.52, CI 1.37–1.69) and component separation (OR 1.34, CI 1.21–1.49) and was negatively associated with fascial closure (OR 0.78, CI 0.69–0.88). Hernia PC was also associated with reoperation, readmission, and development of wound complications (OR 1.18, CI 1.08–1.30; OR 1.15, CI 1.04–1.27; OR 1.28, CI 1.16–1.41, respectively). EAV PC was associated with performance of a panniculectomy (OR 1.33, CI 1.20–1.48), readmission (OR 1.18, CI 1.06–1.32), and wound complications (OR 1.41, CI 1.27–1.57). IAV PC was not associated with adverse outcomes. Values of hernia area, volume, IAV, HV:IAV, BMI, and SQV are collinear markers of patient obesity and hernia proportions. They are distinct enough to be represented by three principal component variables, indicating more nuanced discrete influences on variability of surgical outcomes other than BMI.

Abdominal wall hernia repair is one of the most common operations done by general surgeons today. Patients with incisional hernias can be extremely challenging to manage due to a number of factors that include obesity, prior hernia repairs, previous mesh placement, loss of domain, and other variables. The approach to patients with incisional hernias has evolved considerably over the last 20 years due to both advances in mesh technology and surgical approaches. Key factors in a successful outcome include modification of risk factors prior to surgery such as smoking cessation and weight reduction, selection of mesh appropriate to the hernia type and planned location of the mesh, and broad overlap of mesh beyond the margins of the hernia defect. Newer techniques such as transabdominis release and component separation with retrorectus mesh placement and robotic approaches to abdominal wall hernia are being increasingly utilized in these patients. This article reviews these aspects of abdominal wall hernia repair with a discussion of recent results and the importance of quality improvement and monitoring of outcomes.

Background Complex ventral incisional hernia repair represents a challenging clinical condition in which biologically derived graft reinforcement is often utilized, but little long-term data inform that decision. Urinary bladder matrix (UBM) has shown effectiveness in diverse clinical settings as durable reinforcement graft material, but it has not been studied over a long term in ventral incisional hernia repair. This study evaluates the clinical, radiographic, and histological outcome of complex incisional hernia repair using UBM reinforcement with 12–70 months of follow-up. Methods A single-arm, retrospective observational study of all ventral incisional hernia repairs utilizing UBM reinforcement over a 6-year time frame by a single surgeon was performed. Patients were assessed in long-term follow-up clinically and with the Carolina Comfort Scale. A subset of patients was assessed with abdominal wall ultrasound or CT scan. Three patients had abdominal wall fascial biopsies years after the incisional hernia repair with UBM graft, and the histology is analyzed. Results 64 patients underwent repair of complex incisional hernias with UBM graft reinforcement by a single surgeon. 42 patients had concomitant procedures including large or small bowel resection, excision of infected mesh, evacuation of abscess or hematoma, cholecystectomy, or panniculectomy with abdominoplasty. 16 patients had ostomies at the time of repair. Median follow-up time is 36 months, with a range of 12–70 months. Nine patients (14%) have required surgical repair of a recurrent hernia, and a tenth patient has a recurrence that is managed non-surgically, for a total recurrence rate of 15.6% over the entire time frame. Median time to recurrence was 32 months, and a Kaplan–Meier freedom from recurrence curve is depicted. 28 patients have undergone ultrasound or CT assessments of the abdominal wall which demonstrate radiographic fascial integrity 12–70 months after repair. Three patients have been re-explored for unrelated reasons in the years following ventral incisional hernia repair with UBM, and full thickness fascial biopsies demonstrate a robust remodeling response histologically similar to native myofascial tissue. No patients have developed graft infection, fistulization to the graft, or required graft explantation. Carolina Comfort Scale assessment of 45 patients 3 years after the repair averaged 16 out of a possible 115. Conclusion In 64 patients undergoing complex ventral incisional hernia repair with UBM reinforcement, all have experienced successful resolution of complex clinical conditions and 15.6% of these repairs have recurred at a median follow-up of 3 years. Three full-thickness biopsies of the repaired fascia years later shed light on a promising remodeling response which may signal strength and durability comparable to native fascia.

Posterior component separation (PCS) via the transversus abdominis release (TAR) procedure continues to gain popularity. However, neither the physiologic basis nor the extent of myofascial medialization after TAR is established. We aimed to assess both anterior and posterior rectus fascia (AF and PF) medialization following each step of the TAR procedure. Ten fresh cadavers underwent PCS via TAR. Steps included midline laparotomy (MLL), retrorectus dissection (RRD), incision of the posterior rectus sheath (IPL), transversus abdominis muscle division (TAD), and retromuscular dissection (RMD). Medial advancement of AF and PF was measured following application of 2.5, 5.0 lb, and maximal tension to the fascial edge. Values are represented as mean advancement past midline in centimeters. MLL allowed advancement of 2.5, 3.7, and 4.9 cm. RRD provided advancement of 4.1, 5.9, and 7.6 cm for AF and 4.4, 6.2, and 7.5 cm for PF. IPL provided advancement of 4.2, 6.1, and 8.0 cm for AF and 4.6, 6.6, and 8.3 cm for PF. TAD provided advancement of 4.5, 6.6, and 8.6 cm for AF and 5.3, 7.5, and 9.5 cm for PF. RMD provided advancement of 5.5, 7.9, and 9.9 cm for AF and 6.9, 9.6, and 11.2 cm for PF. Overall, the complete TAR procedure provided AF advancement of 102% and PF advancement of 129%, over baseline. The TAR procedure provides for substantial medial advancement of both anterior and posterior myofascial components of the abdominal wall. Retromuscular dissection deep to the divided transversus abdominis muscle appears to be the key step of the procedure, allowing for effective reconstruction of very wide (≈ 20 cm) defects.

This study aims to compare the outcomes of posterior component separation and transversus abdominis release (PCSTAR) with the open anterior component separation (OACS) technique. OACS, first described by Ramirez et al. (Plast Reconstr Surg 86(3):519–526, 1990), has become an established technique for local myofascial advancement in abdominal hernia surgery. PCSTAR, described by Novitsky et al. (Am J Surg 204(5):709–716, 2012), is being used more frequently and is rapidly becoming the technique of choice in complex ventral hernia repair. Analysis was conducted according to PRISMA guidelines. A systematic search of the MEDLINE, EMBASE and Pubmed databases was performed. Studies reporting exclusively on midline ventral hernia repair were reviewed. Studies describing PCSTAR were selected and compared to matched studies describing OACS. Meta-analysis was used to compare outcomes between the two-pooled groups. Seven studies describing 281 cases of PCSTAR for midline incisional hernia using a retromuscular mesh placement were identified. Six comparable studies describing 285 cases of OACS and retromuscular mesh placement were identified from the same search. Pooled analysis demonstrated a hernia recurrence rate of 5.7% (3.0–8.5) for PCSTAR and 9.5% (4.0–14.9) for OACS. Comparative analysis demonstrated no significant difference between hernia recurrence rate (p = 0.23). The use of bridging mesh was not significantly reduced by the use of PCSTAR (3.1%) when compared to ACS (7.5%) (p = 0.22). No significant difference was found in wound complication rates between PCSTAR and OACS, respectively, ‘superficial’ 10.9 vs 21.6% (p = 0.15); and ‘deep’ 9.5 vs 12.7% (p = 0.53). These data suggest PCSTAR have comparable outcomes to OACS. This analysis is limited by the lack of comparative studies and heterogenicity in the OACS group.

A minority of patients undergoing posterior component separation (PCS) have abdominal wall defects that preclude complete reconstruction of the visceral sac with native tissue. The use of absorbable mesh bridges (AMB) to span such defects has not been established. We hypothesized that AMB use during posterior sheath closure of PCS is safe and provides favorable outcomes. We performed a retrospective review of consecutive patients undergoing PCS with AMB at two hernia centers. Main outcome measures included demographics, comorbidities, and post-operative complications. 36 patients were identified. Post-operative wound complications included five surgical site infections. At a median of 27 months, there were five recurrent hernias (13.9%), 2 of which were parastomal, but no episodes of intestinal obstruction/fistula. Utilization of AMB for large posterior layer deficits results in acceptable rates of perioperative wound morbidity, effective PCS repairs, and does not increase intestinal morbidity or fistula formation.

Abdominal wall hernia is a significant cause for reoperation following laparotomy. Anterior component separation (ACS) is a widely used technique for closure of large abdominal wall defects. We propose that adding scoring of transversalis fascia to ACS can provide additional midline advancement of the anterior rectus sheath. Open ACS was performed in eight cadavers. The medial advancement of the anterior rectus sheath was recorded at three points bilaterally during application of constant load, and again following scoring of the transversalis fascia. This technique was then used on two patients with recurrent, complex ventral hernias which could not be closed with ACS alone. In the cadaver model, transversalis fascia scoring provides additional 34.01, 27.12, and 25.05% advancement at each point compared to ACS. Results were significant. In both patients, primary fascial closure of defects over 20 cm width at midline was achieved. Adding transversalis fascia scoring in a controlled standard fashion to ACS may help surgeons achieve closure of abdominal wall defects when ACS alone is not sufficient. Level of Evidence: Level V, therapeutic study.

Ventral hernia is common, complicating up to 20 % of laparotomies. Plication of the rectus sheath with lateral component separation (LCS) provides a durable repair with acceptable functional outcomes. Additional support to the anterior abdominal wall may be provided by synthetic or biological mesh. Biological grafts invoke local tissue remodeling and result in strong fibrocollagenous tissue able to support the dynamic stressor of the anterior abdominal wall. Biodesign graft is a new graft derived from porcine small-intestine submucosa. We aim to review the use of Biodesign mesh for repair of ventral hernia with LCS. Patients underwent ventral hernia repair completed with plication of the rectus sheath, LCS, and use of an onlay Biodesign graft. Data was collected retrospectively. Key outcome measures included post-operative complications and recurrence. Twelve patients were included for analysis. Mean age was 51.2 years, with 50 % males and a median weight of 87 kg (65–111 kg). Median operative time was 210 min (147 to 278 min) and median length of stay was 4 days. At a mean follow-up of 14.0 months, 8/12 (66 %) developed seroma, 1/12 (8 %) developed abdominal wall abscess, and 1/12 (8 %) suffered flap failure requiring vacuum dressings for closure. No patients were complicated by ventral hernia recurrence. Our results describe an early Australian experience of onlay Biodesign graft in the context of rectus sheath plication with LCS. We report acceptable rates of post-operative complications and recurrence. Level of evidence: IV, therapeutic study.

Methods: A retrospective review of patients with large midline abdominal hernia treated using component separation technique from 2009 to 2013 at General Surgery Department of Kipshidze Central University Hospital was performed. The scoring criteria were wound complications (infection, hematoma, seroma, scin necrosis, secondary healing), time to return to work/normal activities and recurrent hernia. The mean follow-up time was 21 months.

This paper investigates the recognition of the Eye Accessing Cues used in the Neuro-Linguistic Programming as a method for inferring one's thinking mechanisms, since the meaning of non-visual gaze directions may be directly related to the internal mental processes. The direction of gaze is identified by separating the components of the eye (i.e., iris, sclera and surrounding skin) followed by retrieving the relative position of the iris within the eye bounding box that was previously extracted from an eye landmarks localizer. The eye cues are retrieved via a logistic classifier from features that describe the typical regions within the eye bounding box. The simultaneous investigation of both eyes, as well as the eye tracking over consecutive frames, are shown to increase the overall performance. The here proposed solution is tested on four databases proving to have superior performance when compared in terms of recognition rate with methods relying on state of the art algorithms.

Purpose Anterior component separation (ACS) with external oblique release for ventral hernia repair has a recurrence rate up to 32 %. Hernia recurrence after prior ACS represents a complex surgical challenge. In this context, we report our experience utilizing posterior component separation with transversus abdominis muscle release (PCS/TAR) and retromuscular mesh reinforcement.

The component separation technique (CST) was developed to improve the integrity of abdominal wall reconstruction for large, complex hernias. Open CST necessitates large subcutaneous skin flaps and, therefore, is associated with significant ischemic wound complications. The minimally invasive or endoscopic component separation technique (MICST) has been suggested in preliminary studies to reduce wound complication rates post-operatively. In this study, we systematically reviewed the literature comparing open versus endoscopic component separation and performed a meta-analysis of controlled studies.A comprehensive search of electronic databases was completed. All English, randomized controlled trials, non-randomized comparison study, and case series were included. All comparison studies included in the meta-analysis were assessed independently by two reviewers for methodological quality using the Cochrane Risk of Bias tools.63 primary studies (3,055 patients) were identified; 7 controlled studies and 56 case series. The total wound complication rate was lower for MICST (20.6 %) compared to Open CST (34.6 %). MICST compared to open CST was shown to have lower rates of superficial infections (3.5 vs 8.9 %), skin dehiscence (5.3 vs 8.2 %), necrosis (2.1 vs 6.8 %), hematoma/seroma formation (4.6 vs 7.4 %), fistula tract formation (0.4 vs 1.0 %), fascial dehiscence (0.0 vs 0.4 %), and mortality (0.4 vs 0.6 %.) The open component CST did have lower rates of intra-abdominal abscess formation (3.8 vs 4.6 %) and recurrence rates (11.1 vs 15.1 %). The meta-analysis included 7 non-randomized controlled studies (387 patients). A similar suggestive overall trend was found favoring MICST, although most types of wound complications did not show to significance. MICST was associated with a significantly decreased rate of fascial dehiscence and was shown to be significantly shorter procedure.This systematic review and meta-analysis comparing MICST to open CST suggests MICST is associated with decreased overall post-operative wound complication rates. Further prospective studies are needed to verify these findings.

The authors analyzed surgical factors and outcomes data in the largest single institutional study comparing endoscopic (ECS) and open component separation (OCS) in ventral hernia repairs (VHR).A prospectively maintained database was reviewed, identifying 76 patients who underwent component separation for VHR with mesh from 2010 to 2013: 34 OCS and 42 ECS. Comparisons were made for demographics, surgical risk factors, and peri-operative outcomes. Wound complications and hernia occurrence post-operatively were reviewed. Risk analyses were performed to determine the association of pre-operative risk factors with surgical site occurrences.Twenty-five ECS patients underwent subsequent laparoscopic hernia repair, and 17 underwent open repair. Operative time for ECS was longer than OCS (334 vs. 239 min; P0.001); however, there was no difference in length of stay (4 days in both groups, P = 0.64) and estimated blood loss (ECS: 97 vs. OCS: 93 cc, P = 0.847). In a sub-analysis of ECS patients, those who underwent laparoscopic hernia repair had a 96 min shorter operative time (P0.001) and lower EBL (63 vs. 147 cc, P0.001) than open repair. Wound complications were 24% in the ECS (n = 10) and 32% in OCS group (n = 11). There was one midline hernia recurrence in the ECS group (mean follow-up of 8 months, range 0.5-34.5 months) and no hernia recurrences in the OCS group (mean follow-up 10 months, range 0.5-30 months). Three of the patients in the ECS group developed new lateral abdominal wall hernias post-operatively.The ECS group had a significantly longer operative time than the OCS group. Post-operative wound complications were similar between ECS and OCS groups. Patients in the ECS group who underwent subsequent laparoscopic VHR had a shorter operative time and blood loss than open repair.

We here report a 37-year-old woman who had two successful pregnancies following a bilateral harvest of transverse rectus abdominis musculocutaneous (TRAM) flap. The abdominal wall was firmly repaired by component separation as well as external oblique fascial patch grafts. Although she had a scar from a cesarean section and the recovery interval between the harvest and the first postreconstructive pregnancy was less than 2 months, each pregnancy and delivery was uneventful. With the popularization and improvement in TRAM breast reconstruction, there may be an increase in the number of pregnancies without physician’s approval. Our case revealed that a large bilateral anterior sheath defect can be firmly repaired to endure immediate pregnancy without using any synthetic material. Level of Evidence: Level V, risk/prognostic study.

Purpose The ideal approach to complex ventral hernia repair is frequently debated. Differences in processing techniques among biologic materials may impact hernia repair outcomes. This study evaluates the outcomes of hernia repair with a terminally sterilized human acellular dermal matrix (TS-HADM) (AlloMax® Surgical Graft, by C. R. Bard/Davol, Inc., Warwick, RI, USA) treated with low-dose gamma irradiation. Methods A single-arm multi-center retrospective observational study of patients undergoing hernia repair with TS-HADM was performed. Data analyses were exploratory only; no formal hypothesis testing was pre-specified. Results Seventy-eight patients (43F, 35M) underwent incisional hernia repair with a TS-HADM. Mean follow-up was 20.5 months. Preoperative characteristics include age of 56.6 ± 11.1 years, BMI 36.7 ± 9.9 kg/m2, and mean hernia defect size 187 cm2. Sixty-five patients underwent component separation technique (CST) with a reinforcing graft. Overall, 21.8 % developed recurrences. Recurrences occurred in 15 % of patients repaired with CST. Major wound complications occurred in 31 % of patients overall. Based upon CDC surgical wound classification, major wound complications were seen in 26, 40, 56, and 50 % of Class 1, 2, 3, and 4 wounds, respectively. No grafts required removal. Conclusions Hernia recurrences are not uncommon following complex abdominal wall reconstruction. Improved outcomes are seen when a TS-HADM is utilized as reinforcement to primary fascial closure.

Background Abdominal reconstruction of large defects is a challenge, and there is an additional morbidity and mortality when it is associated with emergency laparotomy or laparostomy. This study describes the surgical management of abdominal defects and describes an algorithm for complex abdominal reconstruction. We assessed complications such as fistula formation and the development of incisional hernias following formalised introduction of laparostomy for the management of these emergency patients.

This paper presents multispectral image coding methods based on visible component separation techniques. By coding the visible components separately from other spectral components, the color information can be used without decoding the whole multispectral image. Two types of separation techniques are introduced: one is a direct separation of visible and invisible layers, while the other is a scalable separation. In the scalable separation, visible components are first compressed to produce the base layer bitstream. The enhancement layer data include not only invisible components but also the information on the distortion of the coded visible components. Such a separation technique improves the accuracy of decoded multispectral images especially when visible components are highly compressed. The performance of the proposed methods was evaluated for different bit allocations to visible components. In general, the coding performance reduces when data are divided and coded separately to incorporate scalabilities. Nonetheless, it is found that the proposed scalable approach realizes a peak signal-to-noise ratio PSNR value comparable to that achieved by employing JPEG2000, which incorporates no scalability.

The component separation technique for hernia repair results in significant wound morbidity due to the need for large undermining skin flaps. The endoscopic component separation technique allows for advancement of the abdominal wall while preserving the blood supply originating from the epigastric vessels. This study compares the outcomes following hernia repair utilizing these techniques.A retrospective review of patients undergoing component separation or endoscopic component separation hernia repair from 2008 to 2010. Patients underwent open component separation or endoscopic component separation with closure of the linea alba and reinforcement with mesh.Thirty-five patients that underwent a component separation [14 open component separation (CST) and 21 that underwent endoscopic component separation (ECST)] were identified. There was no difference in hospital length of stay (CST 5.0 ± 3.0 days vs ECST 6.3 ± 3.6 days, P = 0.28) or operating room times (CST; 268 ± 62 min vs ECST; 229 ± 57 min, P = 0.07). Wound complications occurred in 57% of CST and 19% of ECST, P = 0.03. One recurrent hernia was identified in the ECST group with a mean follow up of 8 months (range 1-21 months). No recurrences were seen in the CST group.ECST is associated with comparable hospital length of stay and operative times and reduced wound complications compared to CST.

It was interesting to read about the use of tensiometry as a decision tool for abdominal wall reconstruction with component separation [1]. I want to bring to your notice, however, that the transverse view illustrated in Figure 1B shows but one rectus abdominis muscle. The other rectus abdominis is not shown, thereby making the diagram anatomically incorrect. So it is not possible to understand the depicted surgical repair as to how exactly the component separation is done for abdominal wall reconstruction. The procedure along with an accurate illustration is depicted in an earlier article published in the World Journal of Surgery [2]. References

We are grateful to Dr. Dadhwal for his interest in our recently published article [1]. Special thanks for his important comments regarding Figure 1b. Of course, his doubt about the accuracy of the original illustration is justified; it is correct that the human body has two rectus abdominis muscles. We have corrected Figure 1b to show this. Nevertheless, a modified component separation for smaller defects is still possible when the patient has only one rectus abdominis muscle. This might be the situation in a patient with an unstable scar or hernia of the abdominal wall (e.g., after laparotomy, infection, etc.) and as a result of the previous use of a vertical rectus abdominis myocutaneous (VRAM) flap or transverse rectus abdominis myocutaneous (TRAM) flap (e.g., after breast reconstruction, closure of groin defects, etc.).

Natural electrical activity in the left greater splanchnic nerve during feeding was studied in chronic experiments on dogs. The method of separation of coherent components in pulsed form was used to analyze the discharges: Recording from the nerve was carried out at two points; activity was delayed by the time for its conduction along the nerve between the channels, in the channel which received it first, and it was then led from both channels to the coincidence unit. Spontaneous afferent impulsation was shown to spread among a group of nerve fibers with conduction velocities of between 3.7 and 20 m/sec, and with a mean velocity for the maximum of activity of 9.2±1.0 m/sec. Efferent spontaneous activity was not detected. During feeding with meat, besides spontaneous activity, activity of a group of afferent fibers with conduction velocities within the range 3.7–9.2 m/sec also was found (the mean velocity for the maximum of activity was 5.8±0.7 m/sec), and also activity of a group of efferent fibers with conduction velocities within the range 2.5–9.8 m/sec (mean value for maximum 3.5±0.5 m/sec).

Light-initiated two component receptor potentials and the transmembrane currents which generate them were recorded from ventral nerve photoreceptors ofLimulus polyphemus using intracellular microelectrodes. The magnitude and temporal separation of the two components could be manipulated by using pairs of light pulses of variable duration, repetition rate and intensity; the optimal values of these parameters for component separation varied among preparations, but two components could be obtained fromall ventral nerve photoreceptors tested.