Assessment of adhesion formation to intra-abdominal polypropylene mesh and polytetrafluoroethylene mesh

BACKGROUND: The development of intra-abdominal adhesions, bowel obstruction, and enterocutaneous fistulas are potentially severe complications related to the intraperitoneal placement of prosthetic biomaterials. The purpose of this study was to determine the natural history of adhesion formation to polypropylene mesh and two types of polytetrafluoroethylene (ePTFE) mesh when placed intraperitoneally in a rabbit model that simulates laparoscopic ventral hernia repair. MATERIALS AND METHODS: Thirty New Zealand white rabbits were used for this study. A 10-cm midline incision was performed for intra-abdominal access and a 2 cm x 2 cm piece of mesh (n = 60) was sewn to an intact peritoneum on each side of the midline. Two types of ePTFE mesh (Dual Mesh and modified Dual Mesh, W.L. Gore & Assoc., Flagstaff, AZ) and polypropylene mesh were compared. The rate of adhesion formation was evaluated by direct visualization using microlaparoscopy (2-mm endoscope/trocar) at 7 days, 3 weeks, 9 weeks, and 16 weeks after mesh implantation. Adhesions to the prosthetic mesh were scored for extent (%) using the Modified Diamond Scale (0 = 0%, 1 50%). At necropsy the mesh was excised en bloc with the anterior abdominal wall for histological evaluation of mesothelial layer growth. RESULTS: The mean adhesion score for the polypropylene mesh was significantly greater (P < 0.05) than Dual Mesh at 9 weeks and 16 weeks and modified Dual Mesh at 7 days, 9 weeks, and 16 weeks. Fifty-five percent (n = 11) of the polypropylene mesh had adhesions to small intestine or omentum at necropsy compared to 30% (n = 6) of the Dual Mesh and 20% (n = 4) of the modified Dual Mesh. There was a significantly greater percentage (P < 0.003) of ePTFE mesh mesothelialized at explant (modified Dual Mesh 44.2%; Dual Mesh 55.8%) compared to the polypropylene mesh (12.9%). CONCLUSIONS: Serial microlaparoscopic evaluation of intraperitoneally implanted polypropylene mesh and ePTFE mesh in a rabbit model revealed a progression of adhesions to polypropylene mesh over a 16 week period. The pore size of mesh is critical in the development and maintenance of abdominal adhesions and tissue ingrowth. The macroporous polypropylene mesh promoted adhesion formation, while the microporous nature of the visceral side of the ePTFE served as a barrier to adhesions.     

Combined endoscopic/laparoscopic intragastric resection of gastric stromal tumors

Myogenic neoplasms of the stomach are the most common submucosal mass. Their natural history is indeterminate, and surgical resection is advised regardless of size. These lesions have typically required open resection, but a variety of laparoscopic techniques have been described. We report results of endoscopically guided, laparoscopic intragastric resection. Fourteen lesions have been excised in 13 patients in the last 3.5 years. There were eight women and five men with a mean age of 57 years (range 34—72). All patients were asymptomatic, and no lesions had mucosal ulceration. Eight lesions were located at the gastroesophageal junction, two each at the incisura and posterior body, and one each in the fundus and anterior wall of the corpus. All lesions were predominantly intraluminal, and three were transmural. The diagnosis of a myogenic lesion was confirmed by endoscopic ultrasound in eight patients. The laparoscopic/endoscopic technique included two or three, 2 or 5 mm intragastric trocars; endoscopic suture passage and specimen removal; and laparoscopic intragastric suture repair of the gastric defect. The mean operative time was 186 minutes. The mean size of the resected specimens was 3.8 cm (range 1.5-7.0). There was no mitotic activity on histopathology, and all were considered pathologically benign. The median length of stay was 3.8 days (range 3–8). There was no mortality or operative morbidity. At a mean follow-up of 16.2 months (range 1–32) there has been no local recurrences. A combined laparoscopic/endoscopic intragastric resection is most appropriate for intraluminal, benign-appearing submucosal lesions of the proximal stomach. Presented at the Forty-Second Annual Meeting of The Society for Surgery of the Alimentary Tract, Atlanta, Georgia, May 20–23, 2001 (poster presentation).     

Outcomes for laparoscopic bilateral adrenalectomy

BACKGROUND AND PURPOSE: Laparoscopic adrenalectomy has become the preferred surgical approach to manage adrenal disorders. Bilateral adrenalectomy is performed for diseases that are unresponsive to medical management and, frequently, for neoplastic disease. The aim of this study was to review our experience with laparoscopic bilateral adrenalectomy and to evaluate its safety, efficacy, and outcomes. PATIENTS AND METHODS: Between July 1996 and May 2001, five male and two female patients with a mean age of 46 years (range 15-69 years) presented for bilateral adrenalectomy (pheochromocytoma [N = 3], Cushing's disease [N = 3], and metastatic cancer [N = 1]). All procedures were performed using a lateral transperitoneal approach. One gland was excised, the patient was repositioned to the opposite lateral decubitus position, and the remaining gland was removed. RESULTS: Laparoscopic bilateral adrenalectomy was completed in all seven patients. The mean tumor/gland size on the right was 5.0 cm (range 3.1-7.0 cm) and on the left was 5.6 cm (range 3.6-7.0 cm). The mean operative time was 308 minutes (range 190-430 minutes), and the mean estimated blood loss was 138 mL (range 30-300 mL). One patient with a pheochromocytoma experienced intraoperative hypertension necessitating treatment. There were no postoperative complications. The mean postoperative hospital stay was 5.1 days (range 3-9 days). All patients have been treated postoperatively with daily hydrocortisone and fludrocortisone replacement. After a mean follow-up of 33 months (range 2-45 months), six patients are alive. The patient undergoing bilateral adrenalectomy for metastatic lung cancer died from recurrent disease 13 months after resection. CONCLUSION: Laparoscopic bilateral adrenalectomy is safe and effective. Patients are discharged postoperatively in a relatively short time with few complications. Appropriate steroid replacement and close follow-up allows these patients to return to self-reliance.     

Laparoscopic "radical appendectomy" is an effective alternative to endoscopic removal of cecal polyps

BACKGROUND: The endoscopic removal of cecal polyps can be complicated by hemorrhage, perforation, or incomplete resection. Laparoscopic radical appendectomy represents a safe alternative for the definitive resection and accurate pathologic evaluation of selected cecal polyps. METHODS: Patients with cecal cap polyps not involving the ileocecal valve were candidates for laparoscopic radical appendectomy. Intraoperative colonoscopy and resection of the appendix and cecum to the level of the ileocecal valve were accomplished via three midline ports. For each patient, histologic evaluation by frozen section ruled out malignancy and ensured complete resection. RESULTS: Five patients, four of whom had significant medical comorbidities, presented with large adenomatous polyps contained within the cecum. Each polyp was determined to be unresectable endoscopically; therefore, a laparoscopic radical appendectomy was performed. One patient with cirrhosis also underwent intraoperative liver ultrasonography and biopsies, which contributed to the longest operative time and hospital stay. The histologic diagnosis by frozen section was benign for each patient. The mean operative time was 95 minutes, and the mean length of hospital stay was 1.8 days. No postoperative complications were observed during a mean follow-up of 6 months. CONCLUSION: Laparoscopic "radical appendectomy" is an effective treatment for selected cecal adenomatous polyps. Our ability to resect the polyps completely and avoid a standard right hemicolectomy supports this approach.     

Hemispheric specialization for processing auditory nonspeech stimuli

The left hemisphere specialization for speech perception might arise from asymmetries at more basic levels of auditory processing. In particular, it has been suggested that differences in "temporal" and "spectral" processing exist between the hemispheres. Here we used functional magnetic resonance imaging to test this hypothesis further. Fourteen healthy volunteers listened to sequences of alternating pure tones that varied in the temporal and spectral domains. Increased temporal variation was associated with activation in Heschl's gyrus (HG) bilaterally, whereas increased spectral variation activated the superior temporal gyrus (STG) bilaterally and right posterior superior temporal sulcus (STS). Responses to increased temporal variation were lateralized to the left hemisphere; this left lateralization was greater in posteromedial HG, which is presumed to correspond to the primary auditory cortex. Responses to increased spectral variation were lateralized to the right hemisphere specifically in the anterior STG and posterior STS. These findings are consistent with the notion that the hemispheres are differentially specialized for processing auditory stimuli even in the absence of linguistic information.     

Humanitarianism in surgery

Purpose

Humanitarianism is by definition a moral of kindness, benevolence and sympathy extended to all human beings. In our view as surgeons working in underserved countries, humanitarianism means performing the best operation in the best possible circumstances with high income country (HIC) results and training in-country surgeons to do the same. Hernia Repair for the Underserved (HRFU), a not for profit organization, is developing a long term public health initiative for hernia surgery in Western Hemisphere countries. We report the progress of HRFUs methods to render humanitarian care.

Methods

In a collaborative effort, Creighton University and the Institute for Latin American Concern developed an outpatient surgery site for hernia surgery in Santiago, Dominican Republic. Based on this experience, we developed a sustainable care model by recruiting American and European Hernia Society expert surgeons, staff members they recommended, building relationships with local and industry partners, and selecting local surgeons to be trained in mesh hernioplasty. HRFU then extended the care model to other Western Hemisphere countries.

Results

Between 2004 and 2015, the HRFU elective hernia morbidity and mortality rates for 2052 hernia operations were 0.7 and 0%, respectively. This is consistent with outcomes from HICs and confirms the feasibility of a public health initiative based on the principles of the Preferential Option for the Poor.

Conclusions

HRFU has recorded HIC morbidity and mortality rates for hernia surgery in low and middle income countries and has initiated a new surgical training model for sustainability of effect.

     

Sacrocolpopexy: is there a consistent surgical technique?

Introduction

Sacrocolpopexy is the gold standard treatment for vault prolapse. Current reported standards regarding surgical approach and technique vary. Our aim was to evaluate the surgical techniques used and identify any consistency.

Methods

Electronic surveys were sent to 148 candidates enrolled in a sacrocolpopexy workshop at the 2012 American Urogynecologic Society (AUGS) annual meeting and as a link in the International Urogynecology Association (IUGA) e-magazine. The survey assessed demographics, specific surgical steps including dissection techniques, number and type of sutures, graft materials, and the approach to intraoperative complications.

Results

Within the AUGS group, 61 candidates responded (41 %). From the IUGA membership, 128 responded for a total of 189. Overall, 59 % identified their primary practice as urogynaecology, 43 % having completed a fellowship. Only 33 % reported performing sacrocolpopexy as the primary surgery for vault prolapse. Technical aspects: 99.4 % used polypropylene mesh, with 57 % attaching it to the vagina using non-absorbable monofilament sutures. An average of 3–4 sutures were used on the anterior and posterior walls respectively. Suture location: 22.5 % reported not placing apical sutures and 55.7 % place their anterior wall sutures midway down the vagina. Posteriorly, 47 (30 %) placed sutures through the uterosacral ligaments, 19 (12.4 %) through the levator ani and 15 % extend the mesh to the perineal body. The mesh was attached to the sacrum using permanent sutures by 75 %. Dissection of the sacrum was deemed the most technically difficult aspect.

Conclusion

Surgical technique varies widely despite the level of expertise and training. This study highlights the need for an evaluation of the effect of surgical technique on outcomes.

     

Laparoscopic curative resection of pheochromocytomas

PURPOSE: Pheochromocytomas are relatively uncommon tumors whose operative resection has clear medical and technical challenges. While the safety and efficacy of laparoscopic adrenalectomy are relatively well documented, few studies with extended follow-up have been conducted to measure the success of the procedure for the most challenging of the adrenal tumors. In addition, several reports question the applicability of a minimally invasive approach for sizeable pheochromocytomas. The purpose of our investigation was to assess the outcomes of laparoscopic adrenalectomy for pheochromocytomas in the largest study to date when performed by experienced laparoscopic surgeons. METHODS: All pheochromocytomas removed by the authors from January 1995 to October 2004 were reviewed under an Institutional Review Board approved protocol. Eighty-five percent were documented in a prospective fashion. RESULTS: Eighty consecutive patients underwent laparoscopic resection of 81 pheochromocytomas. Seventy-nine were found in the adrenal (42 left, 35 right, 1 bilateral); 2 were extra-adrenal paragangliomas. Eight patients had multiple endocrine neoplasia syndrome. Two lesions were malignant. There were 48 females and 32 males with a mean age of 45 years (range, 15-79 years). Mean tumor size was 5.0 cm (range, 2-12.1 cm); 41 of these lesions were 5 cm in size or larger. Average operative time and blood loss were 169 minutes (range, 69-375 minutes) and 97 mL (range, 20-500 mL), respectively. Intraoperative hypertension (systolic blood pressure, >170 mm Hg) was reported in 53% of patients and hypotension (systolic blood pressure, <90 mm Hg) in 28% of patients. There were no conversions to open surgery. Mean length of stay was 2.3 days (range, 1-10 days). There were 6 perioperative morbidities (7.5%) and no mortalities. No patient required a blood transfusion. No recurrence of endocrinopathy has been documented at a mean follow-up of 21.4 months. CONCLUSION: Laparoscopic resection of pheochromocytomas, including large lesions, can be accomplished safely by experienced surgeons. A short hospital stay with minimal operative morbidity and eradication of endocrinopathy support the minimally invasive approach for adrenalectomy in the setting of pheochromocytoma.     

A triple-blinded randomized trial comparing the hemostatic effects of large-dose 10% hydroxyethyl starch 264/0.45 versus 5% albumin during major reconstructive surgery

In Canada, hydroxyethyl starch 264/0.45 (HES 264/0.45; molar weight 264 kDa, molar substitution 0.45) has largely replaced albumin as the colloidal fluid of choice for perioperative intravascular volume expansion. The maximum recommended dose of HES 264/0.45 is 28 mL/kg; however, there are no clinical data supporting this limit. In this study we compared the hemostatic effects of HES 264/0.45 versus 5% albumin in doses up to 45 mL/kg over 24 h during major reconstructive head and neck surgery. Fifty patients were randomized to receive HES 264/0.45 or 5% human albumin from the induction of anesthesia until 24 h thereafter. Both albumin and HES 264/0.45 effectively maintained physiologic variables in the perioperative and postoperative periods. The partial thromboplastin time and international normalized ratio were significantly increased in the HES 264/0.45 group compared with the albumin group after infusion of 30 mL/kg and 45 mL/kg (P < 0.05). Factor VIII activity and von Willebrand factor level were significantly reduced in the HES 264/0.45 group compared with the albumin group after infusion of 15 mL/kg, 30 mL/kg, and 45 mL/kg (P < 0.05). Significantly more subjects in the HES 264/0.45 group received allogeneic red blood cell transfusions (P < 0.02). We conclude that HES 264/0.45 infusions >30 mL/kg over 24 h impair coagulation to a greater extent than albumin, possibly leading to more allogeneic transfusions.     

Health Care Expenditures Associated With Skeletal Fractures Among Medicare Beneficiaries, 1999–2005

Fractures impose substantial burdens, in terms of both costs and health, on individuals and health care systems. This is particularly true for older Americans and the Medicare system. The objective of this study was to estimate the costs of care associated with selected fractures among Medicare beneficiaries. This was a retrospective, person‐level, pre/postfracture analysis using administrative data. The study used Medicare claims data from 1999 through 2005 for a 5% sample of Medicare beneficiaries. The subjects included Medicare beneficiaries, ≥65 yr of age, who had at least 13 mo of both Parts A and B coverage and not enrolled in Medicare Advantage and who experienced a closed fracture of the hip, femur, pelvis, tibia/fibula, ankle, distal forearm, nondistal radius/ulna, humerus, clavicle, spine, or wrist, or any fracture of the distal forearm or ankle during the years 2000 through 2005. The main outcome measures were incremental (greater than baseline) and attributable (directly associated) payments for Medicare‐covered services for the first 6 mo after incident fractures. Incremental payments ranged from $7788 (95% CI, $7550–$8025) for distal forearm fractures to $31,310 (95% CI, $31,073–$31,547) for open hip fractures; the attributable payments for distal forearm and hip fractures were $1856 and $18,734, respectively. Fractures are associated with substantial increases in health services utilization and costs among Medicare beneficiaries, but significant proportions of those costs are not directly attributable to fracture treatment. Further research is needed to ascertain other health conditions that are driving costs for Medicare beneficiaries after fractures.