Bruce Ramshaw

Laparoscopic parastomal hernia repair using a nonslit mesh technique

BackgroundThe management of parastomal hernia is associated with high morbidity and recurrence rates (20–70%). This study investigated a novel laparoscopic approach and evaluated its outcomes.MethodsA consecutive multi-institutional series of patients undergoing parastomal hernia repair between 2001 and 2005 were analyzed retrospectively. Laparoscopy was used with modification of the open Sugarbaker technique. A nonslit expanded polytetrafluoroethylene (ePTFE) mesh was placed to provide 5-cm overlay coverage of the stoma and defect. Transfascial sutures secured the mesh, allowing the stoma to exit from the lateral edge. Five advanced laparoscopic surgeons performed all the procedures. The primary outcome measure was hernia recurrence.ResultsA total of 25 patients with a mean age of 60 years and a body mass index of 29 kg/m2 underwent surgery. Six of these patients had undergone previous mesh stoma revisions. The mean size of the hernia defect was 64 cm2, and the mean size of the mesh was 365 cm2. There were no conversions to open surgery. The overall postoperative morbidity was 23%, and the mean hospital length of stay was 3.3 days. One patient died of pulmonary complications; one patient had a trocar-site infection; and one patient had a mesh infection requiring mesh removal. During a median follow-up period of 19 months (range, 2–38 months), 4% (1/25) of the patients experienced recurrence.ConclusionOn the basis of this large case series, the laparoscopic nonslit mesh technique for the repair of parastomal hernias seems to be a promising approach for the reduction of hernia recurrence in experienced hands.

Consequences of Conversion in Laparoscopic Colorectal Surgery

IntroductionLaparoscopic procedures converted to open approaches have been associated with higher complication rates than laparoscopic and open cholecystectomy and appendectomy. Laparoscopic colorectal resections have relatively high conversion rates compared with other laparoscopic procedures. This study was designed to evaluate outcomes of conversions compared with laparoscopic and open colorectal resections.MethodsWe reviewed 498 consecutive colorectal resections performed between 1995 and 2002. Procedures were divided into laparoscopic colorectal resections, open colorectal resections, or conversions. Demographics, underlying disease, type of procedure performed, and operative outcomes were compared between groups.ResultsOf the 238 laparoscopic procedures performed, 182 were completed laparoscopically and 56 (23 percent) required conversion; 260 were performed open. Conversions were associated with greater blood loss (200 (range, 50–750) vs. 100 (range, 30–900) ml), longer time to first bowel movement (82 (range, 40–504) vs. 72 (range, 12–420) hr), and longer length of stay (6 (range, 2–67) vs.. 5 (range, 2–62) days) than the laparoscopic colorectal resections group. There was no difference in operative time, transfusion requirements, intraoperative and postoperative complications, or mortality between conversions and laparoscopic colorectal resections. Conversions resulted in fewer patients requiring transfusions (4 vs. 14 percent), shorter time to first bowel movement (82 (range, 40–504) vs. 93 (range, 24–240) hr), and shorter length of stay (6 (range, 2–67) vs. 7 (range, 2–180) days) than in the open colorectal resections group. There were no differences in complications or mortality between the conversion group and the open colorectal resections group.ConclusionsLaparoscopic colorectal resections has a relatively high conversion rate; however, the converted cases have outcomes similar to open colorectal resections. In fact, the converted group required fewer blood transfusions than the open group. Experience and good judgment are fundamental for timely conversion of a laparoscopic procedure to open to decrease complication rates. Despite a high conversion rate, surgeons should consider laparoscopic colorectal resections, because even when necessary, conversion does not result in poorer outcomes than laparoscopic colorectal resections or open colorectal resections.

Method of preparing a decellularized porcine tendon using tributyl phosphate

Extracellular matrix (ECM) materials are currently utilized for soft tissue repair applications such as vascular grafts, tendon reconstruction, and hernia repair. These materials are derived from tissues such as human dermis and porcine small intestine submucosa, which must be rendered acellular to prevent disease transmission and decrease the risk of an immune response. The ideal decellularization technique removes cells and cellular remnants, but leaves the original collagen architecture intact. The tissue utilized in this study was the central tendon of the porcine diaphragm, which had not been previously investigated for soft tissue repair. Several treatments were investigated during this study including peracetic acid, TritonX-100, sodium dodecyl sulfate, and tri(n-butyl) phosphate (TnBP). Of the decellularization treatments investigated, only 1% TnBP was effective in removing cell nuclei while leaving the structure and composition of the tissue intact. Overall, the resulting acellular tissue scaffold retained the ECM composition, strength, resistance to enzymatic degradation, and biocompatibility of the original tissue, making 1% TnBP an acceptable decellularization treatment for porcine diaphragm tendon.

Use of porcine dermal collagen as a prosthetic mesh in a contaminated field for ventral hernia repair: a case report

Chronic infection of a prosthetic mesh implant is a severe complication of ventral hernia repair, and mesh explantation is usually required in these cases. Biologic mesh implants have a possible role in ventral hernia repair in this setting. Here we present a case of chronic mesh infection following ventral hernia repair and the use of a biologic mesh to repair the existing defect following explantation of the infected mesh. Analysis of the explant material demonstrated possible oxidative degradation of the original polypropylene. A review of the literature follows.

Characterization of heavyweight and lightweight polypropylene prosthetic mesh explants from a single patient

Although polypropylene has been used as a hernia repair material for nearly 50 years, very little science has been applied to studying the bodys effect on this material. It is possible that oxidation of mesh occurs as a result of the chemical structure of polypropylene and the physiological conditions to which it is subjected; this leads to embrittlement of the material, impaired abdominal movement, and chronic pain. It is also possible that lightweight polypropylene meshes undergo less oxidation due to a reduced inflammatory reaction. The objective of this study was to characterize explanted hernia meshes using techniques such as scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and compliance testing to determine whether the mesh density of polypropylene affects the oxidative degradation of the material. The hypothesis was that heavyweight polypropylene would incite a more intense inflammatory response than lightweight polypropylene and thus undergo greater oxidative degradation. Overall, the results support this theory.

Management of anastomotic leaks after Roux-en-Y bypass using self-expanding polyester stents

BACKGROUND To analyze the outcomes of a series of endoscopically placed polyester self-expanding polyflex stents (SEPSs) for the management of anastomotic leaks after Roux-en-Y bypass. Anastomotic leaks after gastric bypass cause significant morbidity and mortality. Covered polyester SEPSs might have a role in the treatment of these leaks. METHODS A retrospective chart review was performed from January 2006 to November 2006 that included all acute and chronic leaks treated with SEPSs. RESULTS A total of 6 patients were treated with stents, with a mean procedure time of 22 minutes. Of these 6 patients, 5 had acute postoperative leaks and 1 had a chronic fistula. Five patients started oral intake 1-6 days after their procedure. All acute leaks had complete healing at a median of 44 days. The patient with a chronic gastrocutaneous fistula required revisional surgery for fistula closure. In addition, 5 patients had stent migration, and 3 required stent replacement. CONCLUSION An endoscopically placed SEPS provides a less-invasive alternative to treat acute anastomotic leaks after Roux-en-Y bypass while simultaneously allowing oral intake. The results of this case series have demonstrated this treatment to be safe and effective.

Materials characterization of explanted polypropylene, polyethylene terephthalate, and expanded polytetrafluoroethylene composites: Spectral and thermal analysis

This study utilized spectral and thermal analysis of explanted hernia mesh materials to determine material inertness and elucidate reasons for hernia mesh explantation. Composite mesh materials, comprised of polypropylene (PP) and expanded polytetrafluoroethylene (ePTFE) mesh surrounded by a polyethylene terephthalate (PET) ring, were explanted from humans. Scanning electron microscopy (SEM) was conducted to visually observe material defects while attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) was used to find chemical signs of surface degradation. Modulated differential scanning calorimetry (MDSC) and thermogravimetric analysis (TGA) gave thermal stability profiles that showed changes in heat of fusion and rate of percent weight loss, respectively. ATR-FTIR scans showed higher carbonyl peak areas as compared to pristine for 91% and 55% of ePTFE and PP explants, respectively. Ninety-one percent of ePTFE explants also exhibited higher C--H stretch peak areas. Seventy-three percent of ePTFE explants had higher heats of fusion while 64% of PP explants had lower heats of fusion with respect to their corresponding pristines. Only 9% of PET explants exhibited a lower heat of fusion than pristine. Seventy-three percent of ePTFE explants, 73% of PP explants, and only 18% of PET explants showed a decreased rate of percent weight loss as compared to pristine. The majority of the PP and ePTFE mesh explants demonstrated oxidation and crosslinking, respectively, while the PET ring exhibited breakdown at the sites of high stress. The results showed that all three materials exhibited varied degrees of chemical degradation suggesting that a lack of inertness in vivo contributes to hernia mesh failure.

Integrated flexible endoscopy training during surgical residency

BackgroundNew advances in endoscopic surgery make it imperative that future gastrointestinal surgeons obtain adequate endoscopy skills. An evaluation of the 2001–02 general surgery residency endoscopy experience at the University of Missouri revealed that chief residents were graduating with an average of 43 endoscopic cases. This met American Board of Surgery (ABS) and Accreditation Council for Graduate Medical Education (ACGME) requirements but is inadequate preparation for carrying out advanced endoscopic surgery. Our aim was to determine if endoscopy volume could be improved by dedicating specific staff surgeon time to a gastrointestinal diagnostic center at an affiliated Veterans Administration Hospital.MethodsDuring the academic years 2002–05, two general surgeons who routinely perform endoscopy staffed the gastrointestinal endoscopy center at the Harry S. Truman Hospital two days per week. A minimum of one categorical surgical resident participated during these endoscopy training days while on the Veterans Hospital surgical service. A retrospective observational review of ACGME surgery resident case logs from 2001 to 2005 was conducted to document the changes in resident endoscopy experience. The cases were compiled by postgraduate year (PGY).ResultsResident endoscopy case volume increased 850% from 2001 to 2005. Graduating residents completed an average of 161 endoscopies. Endoscopic experience was attained at all levels of training: 26, 21, 34, 23, and 26 mean endoscopies/year for PGY-1 to PGY-5, respectively.ConclusionsHaving specific endoscopy training days at a VA Hospital under the guidance of a dedicated staff surgeon is a successful method to improve surgical resident endoscopy case volume. An integrated endoscopy training curriculum results in early skills acquisition, continued proficiency throughout residency, and is an efficient way to obtain endoscopic skills. In addition, the foundation of flexible endoscopic skill and experience has allowed early integration of surgery residents into research efforts in natural orifice transluminal endoscopic surgery.

Assessment of the biocompatibility of two novel, bionanocomposite scaffolds in a rodent model.

Two novel, bionanocomposite scaffolds were evaluated in a rodent model over the course of three months to determine whether these scaffolds possessed adequate biocompatibility characteristics to warrant further evaluation as possible tissue reconstruction scaffolds. These bionanocomposite scaffolds were comprised of amine-functionalized gold nanoparticles (AuNP) or silicon carbide nanowires (SiCNW) crosslinked to an acellular porcine diaphragm tendon. It was hypothesized that the addition of nanomaterials to the porcine tendon would also improve its biocompatibility by imparting a nanostructured surface. As early as seven days after implantation, both types of bionanocomposite scaffolds displayed evidence of granulation tissue and the beginning of scaffold remodeling with new collagen deposited by the host, and by ninety-seven days the bionanocomposite scaffolds were completely remodeled with no evidence of any adverse host tissue reaction or scar tissue formation. The AuNP bionanocomposite scaffolds exhibited accelerated scaffold remodeling compared to the SiCNW scaffolds.

Morbidity associated with laparoscopic repair of suprapubic hernias

BACKGROUND Laparoscopic suprapubic hernia repair (LSHR) is frequently a technically difficult procedure. This is often due to extensive adhesions from multiple previous operations, the necessary wide pelvic dissection, and adequate mesh coverage with transfascial suture fixation. The aim of the current study was to document the complications and morbidity associated with the repair of suprapubic hernias. METHODS A retrospective review of patients with complex suprapubic ventral hernias undergoing laparoscopic repair between 2003 and 2007 at 2 university-based practices by 1 surgeon at each facility was conducted. The operative techniques were similar and included dissection into the space of Retzius to mobilize the dome of the bladder, intraperitoneal onlay of mesh using a barrier mesh, careful tack fixation to the pubic bone and Coopers ligaments, and extensive transfascial suture fixation of the mesh. RESULTS A total of 47 patients were reviewed, 29 women and 18 men, with a mean age of 54 years. Patients averaged 3.5 previous abdominal surgeries (SD +/-2.3) and had a mean body mass index (BMI) of 35.1 (SD +/-7.5). Previous ventral hernia repairs had been performed in 57% of patients. Average defect size was 139.8 cm(2) (SD +/-126) and average mesh size was 453.8 (SD +/-329.0), with an average hernia-to-mesh ratio of 3.2. Median length of stay was 3 days with a mean follow-up of 2.6 months (SD +/-3.1). There were 18 complications (38%): symptomatic seroma (n = 4), prolonged ileus (n = 2), chronic pain (n = 2), postoperative urinary retention (n = 2), enterotomy (n = 1), intraoperative bladder injury (n = 1), postoperative urinary tract infection (n = 1), mesh infection (n = 1), rapid ventricular rate (n = 1), small bowel obstruction (n = 1), pulmonary embolism (n = 1), and pneumonia (n = 1). One patient required conversion to open ventral hernia repair, no injury was identified. Recurrence occurred in 3 patients (6.3%). The mechanisms of recurrence included reherniation at the level of the pubic tubercle, a lateral mesh recurrence in a patient with a high BMI and small abdominal excursion, and in a pregnant patient who developed a fixation suture hernia. CONCLUSIONS Laparoscopic suprapubic hernia repair is safe and effective with a relatively low recurrence rate, considering the complexity of the repair.