Cory N. Criss

Functional abdominal wall reconstruction improves core physiology and quality-of-life

INTRODUCTION One of the goals of modern ventral hernia repair (VHR) is restoring the linea alba by returning the rectus muscles to the midline. Although this practice presumably restores native abdominal wall function, improvement of abdominal wall function has never been measured in a scientific fashion. We hypothesized that a dynamometer could be used to demonstrate an improvement in rectus muscle function after open VHR with restoration of the midline, and that this improvement would be associated with a better quality-of-life. METHODS Thirteen patients agreed to dynamometric analysis before and 6 months after an open posterior component separation (Rives-Stoppa technique complimented with a transversus abdominis muscle release) and mesh sublay. Analysis done using a dynamometer (Biodex 3, Corp, Shirley, NY) included measurement of peak torque (PT; N*m) and PT per bodyweight (BW; %) generated during abdominal flexion in 5 settings: Isokinetic analysis at 45°/s and 60°/s as well as isometric analysis at 0°, -15°, and +15°. Power (W) was calculated during isokinetic settings. Quality-of-life was measured using our validated HerQles survey at the time of each dynamometric analysis. RESULTS Thirteen patients (mean age, 54 ± 9 years; mean body mass index, 31 ± 7 kg/m(2)) underwent repair with restoration of the midline using the aforementioned technique. Mean hernia width was 12.5 cm (range, 5-19). Improvements in PT and PT/BW were significant in all 5 settings (P < .05). Improvement in power during isokinetic analyses at 45°/s and 60°/s was also significant (P < .05). All patients reported an improvement in quality-of-life, which was associated positively with each dynamometric parameter. CONCLUSION Restoration of the linea alba during VHR is associated with improved abdominal wall functionality. Analysis of rectus muscle function using a dynamometer showed statistical improvement by isokinetic and isometric measurements, all of which were associated with an improvement in quality-of-life.

Comparative Radiographic Analysis of Changes in the Abdominal Wall Musculature Morphology after Open Posterior Component Separation or Bridging Laparoscopic Ventral Hernia Repair

BACKGROUND Large ventral hernias are known to induce atrophic changes to the anterior abdominal wall musculature. We have shown that anterior component separation with external oblique (EO) release, with resultant reconstruction of the midline, results in hypertrophy of the rectus muscle (RM), internal oblique (IO), and transversus abdominis (TA). We aimed to compare and contrast the impact of posterior component separation with transversus abdominis release (TAR) and bridging laparoscopic ventral hernia repair (LVHR) on the muscles of the abdominal wall. STUDY DESIGN Preoperative and at least 6-month postoperative CT scans were analyzed for patients undergoing TAR with midline reconstruction and LVHR without midline reconstruction. A change in the measured area of each abdominal wall muscle was used as the determinant of hypertrophy or atrophy. The areas of the RM, EO, IO, and TA were measured at the L3 to L4 level through the axial plane. RESULTS Twenty-five consecutive patients with pre- and postoperative images were analyzed in each group. In the TAR group, the RA, EO, and IO demonstrated significant increases in area. In the LVHR group, no muscles demonstrated any significant changes. CONCLUSIONS Similar to anterior component separation, hernia repair with TAR results in hypertrophy of the rectus abdominis muscle. In addition, we found that TAR was associated with hypertrophy of both external and internal oblique muscles. Bridging repair during LVHR, on the other hand, did not result in any significant changes in any of the abdominal muscles. Our findings provide clear radiologic evidence that re-creation of the midline by means of the TAR leads to improved anatomy of the abdominal wall, in addition to positive compensatory changes of the lateral abdominal wall musculature.

Risk factors for wound morbidity after open retromuscular (sublay) hernia repair

BACKGROUND Retrorectus repairs (RR) of abdominal wall hernias are growing in popularity, yet wound morbidity and predictors in this context have been characterized poorly. Models aimed at predicting wound morbidity typically do not control for technique and/or location of mesh. Our aim was to describe wound morbidity and risk factors specifically in the context of RR hernia repair. Our hypothesis was that the incidence of wound morbidity with mesh sublay would be less than predicted by a model that does not control for mesh position. METHODS Consecutive RR hernia repairs with at least a 90-day follow-up were identified in our prospective database and analyzed. The primary outcome measures were the incidence of surgical-site occurrence (SSO) and surgical-site infection (SSI) via modern, standardized definitions. For predictors of SSO, statistical analysis was performed with univariate analysis, χ(2), and logistic regression as well as multivariate regression. RESULTS A total of 306 patients met the inclusion criteria. Eighty-four SSOs identified in 72 (23.5%) patients included 48 (15.7%) SSIs, 14 (4.6%) instances of wound cellulitis, 12 (3.9%) skin dehiscences, 6 (2.0%) seromas, and 4 (1.3%) hematomas but no instances of mesh excision or fistula formation. Treatment entailed antibiotics alone in 30 patients, 14 bedside drainage procedures, 9 radiographically assisted drainage procedures, and 10 returns to the operating room for debridement. After multivariate analysis, diabetes (OR 2.41), hernia width >20 cm (OR 2.49), and use of biologic mesh (OR 2.93) were statistically associated with the development of a SSO (P < .05). Notably, the mere presence of contamination was not independently associated with wound morbidity (OR 1.83, P = .11). SSO and SSI rates anticipated by a recent risk prediction model were 50-80% and 17-83%, respectively, compared with our actual rates of 20-46% and 7-32%. CONCLUSION Based on a large cohort of patients, we identified factors contributing to SSOs specifically for RR hernia repairs. Paradoxically, biologic mesh was an independent predictor of wound morbidity. The development of clinically important mesh complications and rates of wound morbidity less than anticipated by recent predictive models suggest that the retromuscular (sublay) mesh position may be more advantageous.

Lack of identifiable biologic behavior in a series of porcine mesh explants

INTRODUCTION Biologic matrices used in abdominal wall reconstruction are purported to undergo remodeling into connective tissue resembling native collagen. Key steps in that process include inflammatory response at the mesh/tissue interface, cellular penetration, and neovascularization of the matrix, followed by fibroblast proliferation and collagen deposition. We aimed to examine the concept of biologic mesh remodeling/regeneration in a series of explanted porcine biologic meshes. MATERIALS AND METHODS A cohort of patients who underwent removal of porcine biologic mesh was identified in a prospective database. Mesh/tissue samples were analyzed using standard hematoxylin/eosin and Massons trichrome staining. Main outcome measures included: inflammatory response at the mesh/tissue interface, foreign body reaction (FBR), cellular penetration, neovascularization, and new collagen deposition. All evaluations were performed by a blinded senior pathologist using established grading scales. RESULTS A total of 14 cases with implant time ranging from 4 to 33 months were identified and analyzed. All meshes were placed as intraperitoneal underlay. There were 7 non-cross-linked and 7 cross-linked grafts. Cross-linked grafts were associated with mild FBR and moderate fibrous capsule formation. Similarly, non-cross-linked grafts had mild-to-moderate FBR and encapsulation. Furthermore, non-cross-linked grafts were associated with no neovascularization and minimal peripheral mesh neocellularization. Cross-linked grafts demonstrated neither neovascularization nor neocellularization. Although no grafts were associated with any quantifiable new collagen deposition within the porcine biologic matrix, minimal biodegradation/remodeling was observed at the periphery of the non-cross-linked grafts only. CONCLUSION The biologic behavior of porcine meshes is predicated on their ability to undergo mesh remodeling with resorption and new collagen deposition. In the largest series of human biologic explants, we detected no evidence of xenograft remodeling, especially in the cross-linked group. Although underlay mesh placement and other patient factors may have contributed to our findings, the concept of porcine biologic mesh regeneration does not seem to be prevalent in the clinical setting.

Selective Management of Multiple Bronchopleural Fistulae in a Pediatric Patient on Extracorporeal Membrane Oxygenation: A Multidisciplinary Approach

INTRODUCTION This case highlights the successful utilization of a multidisciplinary approach to numerous bilateral bronchopleural fistulae (BPF) using minimally invasive techniques. In this study, we present a previously healthy 14-year-old male hospitalized with 2009 H1N1 influenza and methicillin-resistant Staphylococcus aureus coinfection complicated by severe acute respiratory distress syndrome and multifocal necrotizing pneumonia, with significant lung tissue damage requiring prolonged extracorporeal membrane oxygenation (ECMO) support. METHODS The development of multiple BPFs precluded lung recruitment necessary to wean from ECMO. Treatment options were very limited and endobronchial valves were considered. However, localizing single airleaks with a fogarty balloon is normally the technique to determine appropriate location to place the valves. With multiple fistulae, this technique would be ineffective. Therefore, the patient was brought to interventional radiology and bronchography was performed for selective fistula mapping. With this precise localization, the multiple fistulae were ultimately controlled using image-guided embolization and the placement of multiple endobronchial valves. The success of this intervention enabled positive pressure ventilator support and rehabilitation required for weaning from ECMO support. CONCLUSION This case highlights the successful utilization of a multidisciplinary approach to numerous bilateral BPFs using minimally invasive techniques.

Training in Advanced Endoscopic Procedures

Despite initially developed by surgeons, endoscopy is an invaluable tool that was refined by, and is principally used, by gastroenterologists. Over the years, there has been significant controversy between the two subspecialties regarding residency training requirements and credentialing. To meet the demands of increased need and utilization of endoscopy, educational and clinical collaboration between surgeons and gastroenterologists is required, as this will greatly impact patient outcomes and experience with this great tool.