The prophylactic efficacy of rifampicin-soaked graft in combination with systemic vancomycin in the prevention of prosthetic vascular graft infection: an experimental study

OBJECTIVE: To investigate the prophylactic efficacy of systemic, topical, or combined antibiotic usage in the prevention of late prosthetic vascular graft infection caused by methicillin-resistant Staphylococcus epidermidis (MRSE) and the differential adherence of S. epidermidis to Dacron and ePTFE grafts in a rat model. MATERIALS AND METHODS: Graft infections were established in the back subcutaneous tissue of 120 adult male Wistar rats by implantation of 1-cm(2) Dacron/ePTFE prosthesis followed by topical inoculation with 2 x 10(7) CFU of clinical isolate of MRSE. Each of the series included one group with no graft contamination and no antibiotic prophylaxis (uncontaminated control), one contaminated group that did not receive any antibiotic prophylaxis (untreated control), one contaminated group in which perioperative intraperitoneal prophylaxis with vancomycin (10 mg/kg) was administered, two contaminated groups that received rifampicin-soaked (5 mg/1 ml) or vancomycin-soaked (1 mg/1 ml) grafts, and one contaminated group that received a combination of rifampicin-soaked (5 mg/1 ml) graft with perioperative intraperitoneal vancomycin prophylaxis (10 mg/kg). The grafts were removed sterilely 7 days after implantation and evaluated by using sonication and quantitative blood agar culture. RESULTS: MRSE had significantly greater adherence to Dacron than ePTFE grafts in the untreated contaminated groups (P < 0.001). Rifampicin had better efficacy than vancomycin in topical application, but the difference was not statistically significant (P > 0.05). Intraperitoneal vancomycin showed a significantly higher efficacy than topical vancomycin or rifampicin (P < 0.001). The best results were provided by a combination of intraperitoneal vancomycin in rifampicin-soaked graft groups (P < 0.001). CONCLUSIONS: The combination of rifampicin and intraperitoneal vancomycin seems to be the best choice for the prophylaxis of late prosthetic vascular graft infections caused by MRSE.     

Minimal adhesions to ePTFE mesh after laparoscopic ventral incisional hernia repair: reoperative findings in 65 cases

BACKGROUND AND OBJECTIVES: Laparoscopic ventral incisional hernia repair involves intraabdominal placement of a synthetic mesh, and the possibility of formation of severe visceral adhesions to the prosthesis is a principal concern. Little clinical information based on reoperative findings is available about adhesions to biomaterials placed intraabdominally. We conducted a multi-institutional study of adhesions to implanted expanded polytetrafluoroethylene (ePTFE) mesh at reoperation in patients who had previously undergone laparoscopic incisional hernia repair done with the same mesh implantation technique. METHODS: Nine surgeons retrospectively assessed the severity of adhesions to ePTFE mesh at reoperation in 65 patients. For each case, adhesions were assigned a score of 0 to 3, with 0 indicating no adhesions and 3 severe adhesions. RESULTS: The mean time from mesh implantation to reoperation was 420 days (range, 2-1 739 days). No adhesions were observed in 15 cases. Forty-four cases received an adhesion score of 1, and 6 cases a score of 2; no scores of 3 were assigned. Thus, 59 patients (91 %) had either no or filmy, avascular adhesions. No enterotomies occurred during adhesiolysis. CONCLUSIONS: In this large series of reoperations after laparoscopic incisional hernia repair, no or minimal formation of adhesions to implanted ePTFE mesh was observed in 91 % of cases, and no severe cohesive adhesions were found. Comparative analyses of newer materials based on clinical reoperative findings are warranted to assess the safety of intraabdominally placed meshes.     

Long-term Outcome of a Cuffed Expanded PTFE Graft for Hemodialysis Vascular Access

BACKGROUND: Development of venous outflow stenosis has been a major obstacle in maintaining the patency of dialysis vascular grafts. In the present study, we retrospectively analyzed the long-term results of cuffed expanded polytetrafluoroethylene (ePTFE) and non-cuffed (standard) ePTFE grafts placed for hemodialysis access. MATERIALS AND METHODS: A total of 67 patients who underwent placement of either cuffed (n = 41) or standard (n = 26) ePTFE grafts were retrospectively analyzed. There were no significant differences between the two groups with regard to age, gender, cause of end-stage renal disease, and anatomic placement of the graft. Endpoints consisted of primary (without any intervention) and secondary (with radiological or surgical intervention) graft patency rates at 1-3 years. RESULTS: There was a trend toward better primary graft patency rates in the cuffed versus the standard ePTFE: 37.7% vs. 25.7% at 1 year, 35% vs. 10.3% at 2 years, 28% vs. 5.1% at 3 years, respectively (p = 0.086, Kaplan-Meier). Secondary patency rates in the cuffed group were significantly superior (p = 0.047) to those in the standard group (81.8% vs. 56.1% at 1 year, 61.8% vs. 46.3% at 2 years, 51.5% vs. 33.1% at 3 years, respectively). Thrombosis as a cause of complete graft failure was significantly higher (34%) in the standard group than in the cuffed group (9%) (p = 0.0125). CONCLUSIONS: Compared to the standard ePTFE, the cuffed ePTFE graft provided better long-term outcome, especially in terms of secondary patency rates after radiological intervention.     

Minimal adhesions to ePTFE mesh after laparoscopic ventral incisional hernia repair: reoperative findings in 65 cases.

OBJECTIVES: Laparoscopic ventral incisional hernia repair involves intraabdominal placement of a synthetic mesh, and the possibility of formation of severe visceral adhesions to the prosthesis is a principal concern. Little clinical information based on reoperative findings is available about adhesions to biomaterials placed intraabdominally. We conducted a multiinstitutional study of adhesions to implanted expanded polytetrafluoroethylene (ePTFE) mesh at reoperation in patients who had previously undergone laparoscopic incisional hernia repair done with the same mesh implantation technique. METHODS: Nine surgeons retrospectively assessed the severity of adhesions to ePTFE mesh at reoperation in 65 patients. For each case, adhesions were assigned a score of 0 to 3, with 0 indicating no adhesions and 3 severe adhesions. RESULTS: The mean time from mesh implantation to reoperation was 420 days (range, 2 to 1739 days). No adhesions were observed in 15 cases. Forty-four cases received an adhesion score of 1, and 6 cases a score of 2; no scores of 3 were assigned. Thus, 59 patients (91%) had either no or filmy, avascular adhesions. No enterotomies occurred during adhesiolysis. CONCLUSIONS: In this large series of reoperations after laparoscopic incisional hernia repair, no or minimal formation of adhesions to implanted ePTFE mesh was observed in 91% of cases, and no severe cohesive adhesions were found. Comparative analyses of newer materials based on clinical reoperative findings are warranted to assess the safety of intraabdominally placed meshes.     

Intraperitoneal modification of the Rives-Stoppa repair for large incisional hernias

Introduction Recurrence rates for open repair of ventral/incisonal hernias historically range from 6% for the classic Rives-Stoppa repair to 35–45% for some of the techniques more commonly used in the United States. We report a modification to the classic Rives-Stoppa repair that allows intraperitoneal placement of the prosthetic, secured with a running suture. The abdominal muscles are closed over the mesh to protect it from any superficial wound problems that might develop and to restore normal architecture of the abdominal wall. Method A chart review was undertaken on all patients undergoing open ventral incisional hernia repair by a single surgeon from 2000 to 2006. All hernias were repaired with the intraperitoneal modification mimicking the principles of the Rives-Stoppa repair. Patient characteristics and operative and postoperative data were collected. Primary outcome was recurrence of hernia. Secondary outcomes were complications and rate of mesh infection. Results One hundred and fifteen patients were evaluated. Thirty-four patients had repair of recurrent ventral hernias. The average patient was obese, female, and 59 years old. Twenty-five patients used tobacco, eleven were diabetic, and seven used chronic corticosteroids. Meshes utilized included ePTFE, coated polyester, coated polypropylene, and biologic mesh. Average size of mesh was 465.4 cm². There were four recurrences (3.4%), three of which were due to mesh infection requiring mesh removal. Recurrence rate not secondary to mesh removal was 0.9%. Complications occurred in 26% with seroma formation being the most frequent (16%). Conclusion The intraperitoneal modification to the original Rives-Stoppa repair leads to a very low recurrence rate for large ventral hernia repairs with minimal complications and low rate of mesh infection. Presented at the 2007 American Hernia Society Meeting, Hollywood, FL, USA.     

Intra-abdominal placement of antimicrobial-impregnated mesh is associated with noninfectious fever

The antimicrobial, silver/chlorhexidine, when impregnated on mesh has been demonstrated to resist mesh infection in in vitro and in vivo models. The clinical, human systemic response to intraperitoneal placement of silver/chlorhexidine-impregnated mesh has not been investigated to date. Between October 2002 and November 2004, all in-patients undergoing laparoscopic ventral hernia repair were retrospectively analyzed. All repairs used expanded polytetraflouroethylene (ePTFE) Dual Mesh (DM) or ePTFE impregnated with silver/chlorhexidine, Dual Mesh Plus (DM+). Patient demographics, hernia characteristics, mesh type, operative details, and hospital course data were collected. Noninfectious fevers were defined as a temperature greater than 100.4 F without an identified source. Standard statistical methods were used. During the 2-year study period, 120 patients underwent laparoscopic ventral hernia repair (DM = 55, DM+ = 65). The two groups were similarly matched in terms of age, body mass index, American Society of Anesthesiologists score, defect size, and mesh size. Postoperative fever without an identified source occurred in 10 (18.2%) patients with DM and in 25 (38.5%) patients using DM+ (P = 0.015). A multivariant analysis revealed that only mesh type and body mass index predicted postoperative fever. All fevers resolved within the first 72 hours in the DM patients; however, 16 per cent of the DM+ group had persistent fevers of unknown origin after 72 hours. Within the DM+ group, patients with postoperative fevers had significantly longer postoperative stays (4.8 days vs 3.0 days; P = 0.009). The use of antimicrobial-impregnated ePTFE mesh with silver/chlorhexidine in laparoscopic ventral hernia repair is associated with noninfectious postoperative fever. In our patients, the evaluation and management of these fevers resulted in a significantly longer hospital stay.     

Open and laparoscopic approach in incisional hernia repair with ePTFE prosthesis

BACKGROUND: The aim of this retrospective study was to analyze the results of incisional hernia laparoscopic and open surgery, focusing on the morbidity and postoperative implications. MATERIALS AND METHODS: A group of 106 (42 men, 64 women) patients suffering from incisional hernias were treated with either a laparoscopic (30) or an open (76) placement of a prosthetic mesh between January 1997 and December 2004. The age and gender of the patients, the size and type of the mesh, operation note, the length of postoperative hospital stay, and morbidity were recorded. RESULTS: An expanded polytetrafluoroethylene (ePTFE) mesh was used in 103 patients, whereas a polypropylene mesh was used in 3 patients. In the open technique, 3 patients with the ePTFE prosthetic material developed a mesh infection and required a mesh removal, which was easily performed under local anesthesia. Moreover, 2 patients from the same group developed a hernia recurrence. As for the laparoscopic approach, the only complication observed was one hernia recurrence. Finally, it should be mentioned that 1 patient with a polypropylene mesh developed a colocutaneous fistula. CONCLUSIONS: The benefits of the laparoscopic mesh technique, compared to the open technique, include a shorter hospital stay, less postoperative pain, and possibly, a reduction in wound and mesh complications. Regarding the recurrence rate, the two techniques show similar results.     

Expanded polytetrafluoroethylene membrane for the prevention of peridural fibrosis after spinal surgery: a clinical study

Peridural fibrosis developing after laminectomy may cause pain that can necessitate reoperation. Many materials have been used as a barrier to invasion of fibrous tissue into the vertebral canal, but the ideal material has not been found. Various studies in animals have achieved favourable results with an expanded polytetrafluoroethylene (ePTFE) membrane. In a prospective, randomized study, we compared postoperative results in 33 patients who had an ePTFE membrane implanted to cover the defect caused by laminectomy during lumbar spine decompression with the results in 33 patients in whom no material was implanted. At operation, an ePTFE membrane was placed after the decompression procedure to cover the laminectomy defect completely. Systematic clinical and MRI follow-up evaluations of patients with and without the membrane were conducted 3, 6, 12, and 24 months postoperatively. The effect of ePTFE membrane implantation over laminectomy sites on postoperative peridural fibrosis, pain and neurological claudication was assessed. The ePTFE-membrane group had a significantly lower rate of epidural fibrosis on MRI (P < 0.0001) and of clinical manifestations of radiculalgia (P = 0.002) compared with the no-material group. Epidural fibrosis that occurred in the ePTFE group was generally less extensive than that in the no-material group. There was no significant difference in the rate of postoperative claudication in the two groups. Significantly more seromas occurred in the ePTFE group (P = 0.0002). There were no infections or other complications in either group. The results showed that placement of an ePTFE spinal membrane over the laminectomy defect produced by lumbar spine surgery provided a physical barrier to invasion of fibrous tissue into the vertebral canal, and patients with the membrane had less postoperative radicular pain. Received: 24 November 1997 Revised: 26 November 1998 Accepted: 2 December 1998     

A prospective randomized study of bovine carotid artery biologic graft and expanded polytetrafluoroethylene for permanent hemodialysis access

Objective

Arteriovenous grafts (AVGs) remain reliable substitutes for permanent hemodialysis access in scenarios that preclude the placement of native arteriovenous fistulas (AVFs). The majority of AVGs are constructed of expanded polytetrafluoroethylene (ePTFE), which is relatively inexpensive and readily available, but synthetic AVGs have poor patency rates. On the other hand, biologic grafts confer an advantage by virtue of their inherent similarity to the native human vasculature. However, evidence to support the current preference of synthetic conduits over biologic grafts in clinical practice is scarce. The aim of this protocol is to propose a contemporary re-evaluation and comparison between ePTFE and bovine carotid artery (BCA) grafts.

Incisional herniorrhaphy with intraperitoneal composite mesh: a report of 95 cases

Incisional herniorrhaphy remains a formidable challenge to the general surgeon. Recurrence rates after primary repair are reported between 31-54 per cent while tension-free repairs with prosthetic mesh have lowered this rate to 10 per cent. Repairs with composite mesh (polypropylene/ePTFE) have been gaining in popularity due to the ease of mesh placement in the intraperitoneal location. This paper reviews our experience with composite repairs at a teaching community hospital. A retrospective chart review was performed which evaluated all patients undergoing abdominal incisional hernia repairs over a 4(1/2)-year period. The data were analyzed for mortality, recurrence, infection, subsequent bowel obstruction, and fistula formation. Two hundred twenty-one incisional herniorrhaphies were identified in the resident database of which 95 were repaired with Composix mesh (Bard Surgical, Cranston, RI) in the intraperitoneal position. There were two (2%) recurrences and eight (8%) infections. Fistulization to the small bowel from exposed polypropylene occurred in one patient. There were no bowel obstructions. One postoperative death occurred secondary to pulmonary embolus. Mesh removal was required in all infected cases, and there was a high incidence (63%) of methicillin-resistant Staphylococcus aureus (MRSA). Our findings parallel the low recurrence rate following prosthetic repair. We have reported a higher than expected infection rate particularly with MRSA. Although repairs with Composix mesh are highly successful in regard to recurrence, the high infection rate and resulting morbidity needs to be further evaluated.     

Deep prosthesis infection in incisional hernia repair: predictive factors and clinical outcome.

OBJECTIVE: To evaluate the incidence of prosthetic infection in incisional hernia repairs, to determine whether there are any factors associated with prosthetic infection and to describe the clinical outcome. DESIGN: Retrospective clinical study. SETTING: Teaching hospital, Germany. SUBJECTS: 121 consecutive patients who underwent incisional hernia repair in our department from December 1994 to December 1999. INTERVENTION: Hernia repair by implantation of an alloplastic prosthesis by the Stoppa-Rives technique. MAIN OUTCOME MEASURES: Postoperative deep prosthetic infection and associated factors. RESULTS: All 121 patients had the mesh implanted in the subfascial plane, 77 had a polypropylene mesh (Prolene) (64%), 7 had a polyester mesh (Mersilene) (6%), and 37 patients had a expanded polytetrafluoroethylene patch (ePTFE, Gore-Tex) (31%). Postoperatively the mesh became infected in 8 patients (7%), a mean of 4.5 months (range 0.5-16) after hernia repair. All three infected ePTFE patches had to be removed whereas drainage was sufficient treatment for the infected polypropylene and polyester meshes. CONCLUSION: Once a mesh infection is verified adequate drainage seems to be sufficient for polypropylene and polyester meshes but ePTFE patches should be removed.     

The use of covered nitinol stents to salvage dialysis grafts after multiple failures

The increasing number of patients requiring hemodialysis and the limited number of access sites have resulted in an increase in multiple graft revisions to maintain access for hemodialysis. Venous outflow or anastomotic stenoses in vascular grafts tend to recur and contribute to the difficulty in maintaining a functioning graft. Thus, extending the life of a failed graft becomes an important objective of this study, which was to assess the use of covered nitinol stents to salvage expanded polytetrafluoroethylene (ePTFE) grafts with venous anastomotic or outflow stenosis that have failed after multiple revisions. This is a review of 8 failed non-autogenous ePTFE grafts with isolated venous anastomotic or proximal outflow stenoses that had undergone multiple previous revisions, had failed percutaneous transluminal angioplasty (PTA), and required placement of a covered nitinol stent. Graft locations were forearm (2), upper arm (4), and femoral (2). The mean number of interventions per patient before stent placement was 5.87 thrombectomies (range 2-28) and 3.38 balloon angioplasties (range 2-19). Five patients had 0.62 interposition grafting and 3 had patch angioplasty. All 8 patients (100%) underwent successful dialysis after thrombectomy and stenting. The primary and secondary patency rates after stent placement were 50% and 75%, and 25% and 75%, at 3 and 6 months, respectively. Percutaneous thrombectomy, balloon angioplasty, and concomitant covered nitinol stent placement extend the function of hemodialysis access grafts that have previously failed multiple times.     

An unusual cause of chronic anemia and abdominal pain caused by transmural mesh migration in the small bowel after laparoscopic incisional hernia repair

Mesh repair of incisional hernia is recommended to reduce recurrence. Recognized complications include mesh infection and fistula. Composite meshes with antiadhesive barriers were designed for intraperitoneal placement to reduce adhesion formation and fistulization to the viscera. Transmural mesh migration is a rare complication of hernia repair with composite mesh and can be present with a variety of symptoms. We report an interesting case of transmural mesh migration into the small bowel presenting with chronic microcytic anemia and abdominal pain 5 years after laparoscopic incisional hernia repair with a composite polypropylene/ePTFE mesh.     

Comparison of small-intestinal submucosa and expanded polytetrafluoroethylene as a vascular conduit in the presence of gram-positive contamination

OBJECTIVE: As a vascular conduit, expanded polytetrafluoroethylene (ePTFE) is susceptible to graft infection with Gram-positive organisms. Biomaterials, such as porcine small-intestinal submucosa (SIS), have been successfully used clinically as tissue substitutes outside the vascular arena. SUMMARY BACKGROUND DATA: In the present study, we compared a small-diameter conduit of SIS to ePTFE in the presence of Gram-positive contamination to evaluate infection resistance, incorporation and remodeling, morphometry, graft patency, and neointimal hyperplasia (NH) development. METHODS: Adult male mongrel pigs were randomized to receive either SIS or ePTFE (3-cm length, 6-mm diameter) and further randomized to 1 of 3 groups: Control (no graft inoculation), Staphylococcus aureus, or mucin-producing S epidermidis (each graft inoculation with 10 colonies/mL). Pressure measurements were obtained proximal and distal to the graft to create the iliac/aorta pressure ratio. Morphometric analysis of the neointima and histopathologic examinations was performed. Other outcomes included weekly WBC counts, graft incorporation, and quantitative culture of explanted grafts. RESULTS: Eighteen animals were randomized. All grafts were patent throughout the 6-week study period. Infected SIS grafts had less NH and little change in their iliac/aorta indices compared with infected ePTFE grafts. Quantitative cultures at euthanasia demonstrated no growth in either SIS group compared with 1.7 x 10(4) colonies for ePTFE S aureus and 6 x 10(2) for ePTFE S epi (each P < 0.001). All SIS grafts were incorporated. Histology demonstrated remodeling into host artery with smooth muscle and capillary ingrowth in all SIS groups. Scanning electron micrography illustrated smooth and complete endothelialization of all SIS grafts. CONCLUSIONS: Compared with ePTFE, SIS induces host tissue remodeling, exhibits a decreased neointimal response to infection, and is resistant to bacterial colonization. SIS may provide a superior alternative to ePTFE as a vascular conduit for peripheral vascular surgery.     

Postoperative infection after duraplasty with expanded polytetrafluoroethylene sheet

Dural reconstruction is a significant problem in many cases of decompressive craniotomy and dural defect. Expanded polytetrafluoroethylene (ePTFE) sheet have been used as a dura mater substitute for duraplasty. The outcomes of 83 consecutive patients at our institution were reviewed who underwent external decompression and closure with the ePTFE sheet between August 1995 and December 2000. Eight cases of infection occurred. Seven patients had infection with subdural empyema after cranioplasty with autologous bone. Three patients improved after removal of only the infected bone. One patient improved after removal of the infected bone and ePTFE sheet. One patient experienced wound infection after the original operation. Four patients subsequently developed local and severe inflammation with skin erythema until the ePTFE sheet was removed. Four patients had severe recurrent infections which required subsequent therapy such as vascularized free rectus abdominis muscle flap transfer. Duraplasty with ePTFE sheet might promote infection and poor circulation in the skin flap. The ePTFE sheet should be removed at an early stage in a patient with infection.     

Open intraperitoneal hernia repair for treatment of abdominal wall defects--early results by placement of a polypropylene-ePTFE-mesh

BACKGROUND: Large incisional hernias are mainly repaired today by tension free implantations of prosthetic meshes using various placement methods. The advantages of the intraperitoneal open technique (IPOM) using a polypropylene mesh that is coated with ePTFE on the side facing the intestine, are described. METHODS AND RESULTS: 62 patients underwent an incisional hernia operation with the intraperitoneal positioning of a prosthetic mesh. The follow-up examinations after a range of 16.1 months showed a hernial recurrence rate of 6.4 %. A part of the resulting mesh infections (11.2 %) healed without surgical removal of the mesh. Clinical complications due to adhesion formation were not observed. CONCLUSION: The tissue sparing intraabdominal positioning technique simplifies the necessary overlap using healthy tissue as a prerequisite for a sufficient hernia repair exploiting the intraabdominal pressure.     

Management of the rectal stump after emergency sub‐total colectomy: which surgical option is associated with the lowest morbidity?

OBJECTIVE: To identify the preferred surgical management of the rectal stump after emergency subtotal colectomy (ESC) for acute severe colitis by assessing the morbidity associated with each option. PATIENTS AND METHODS: Consecutive patients undergoing ESC at a district general hospital between 1999 and 2004 were retrospectively audited for pathology, rectal stump complications and length of postoperative hospital stay (POS). RESULTS: Thirty-seven ESCs were performed, 34 were undertaken for disease refractory to medical treatment, 2 for toxic mega colon and 1 for perforation. Thirty-four cases were for ulcerative colitis, 2 Crohn's colitis and 1 infective colitis. Twenty-seven had an intraperitoneal and 10 a subcutaneously placed closed rectal stump. The median POS for patients with a subcutaneously placed stump was shorter than for those with an intraperitoneal stump, 8 and 15 days, respectively (P = 0.04). Two patients had leakage from an intraperitoneal stump, prolonging POS (33 and 193 days). Three of the subcutaneous stumps leaked causing wound infection but not prolonging the POS (6, 7 and 16 days). CONCLUSION: Avoiding a second stoma by closing the rectal stump after ESC has been confirmed as acceptable practice by studies over the last 15 years, reporting no overall increase in complications. The location of a closed rectal stump appears to influence the incidence of pelvic sepsis. The lowest pelvic sepsis rate is associated with subcutaneous placement; despite a higher wound infection rate this option appears to be associated with a lower total morbidity reflected in a shorter POS.     

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.     

Limited-conversion technique: a safe and viable alternative to conversion in laparoscopic ventral/incisional hernia repair

BACKGROUND: During laparoscopic ventral/incisional hernia repair (LVIHR), conversion to conventional (open) technique is required when safe adhesiolysis is not possible, incarcerated bowel in hernial sac cannot be reduced or for repair of iatrogenic enterotomies. A formal laparotomy in these circumstances entails significant morbidity due to factors such as wound infection, prolonged immobility, and longer hospital stay. MATERIALS AND METHODS: During a period between 1994 and 2007, 1,503 LVIHRs were performed at our centre following a standardized protocol by five consultants and fellows. Out of these, 6 patients had a formal laparotomy in the initial part of our experience and 26 patients had a limited conversion to facilitate completion of LVIHR. We have devised the term "limited conversion" for the procedure wherein bowel reduction/adhesiolysis/enterotomy repair was performed through a small targeted skin incision. This was followed by laparoscopic placement of intraperitoneal mesh. RESULTS: Conversion to an open procedure was required in 32 (2.1%) out of 1,503 LVIHR procedures. Twenty-six patients underwent a limited conversion and completion of the repair by laparoscopy. All but one of these patients had intraperitoneal placement of mesh by laparoscopic route. The wound complication rate was 3.8% (one patient), the mean hospital stay was 2.1 days, and mean operative time was 124 min. CONCLUSION: Limited conversion offers a safe alternative to a formal laparotomy in patients with bowel incarcerated in hernial sacs or in patients requiring extensive bowel adhesiolysis. Patient morbidity is reduced due to the targeted skin incision whilst retaining several advantages of a minimal access approach viz. laparoscopic evaluation of the entire abdominal wall and placement of a large intraperitoneal prosthesis.     

开放式完全腹腔内修补治疗巨大腹壁切口疝10例

目的探讨用Gore—Tex补片开放式完全腹腔内修补治疗巨大腹壁切口疝的疗效。方法用Gore．Tex补片开放式完全腹腔内修补治疗巨大腹壁切口疝10例，其中初发切口疝9例，复发切口疝1例。结果9例一期愈合，1例发生创面局限性积液，经穿刺负压引流处理后治愈，随访10个月至2年，无复发病例。结论用Gore—Tex补片开放式完全腹腔内修补治疗巨大腹壁切口疝经济，安全，有效，感染风险降低。