BSAVA Manual of Canine and Feline Anaesthesia and Analgesia, 2nd Ed.

The late appearance of incisional hernias several years after laparotomy and the high recurrence rates after operation strongly imply the presence of a disorder of the connective tissue, although a specific defect in patients with incisional hernias has not yet been identified. In the present study we used both immunohistochemistry and Western blot analysis to evaluate the ratio of collagen I and III and the expression of the metalloproteinases (MMP) 1 and 13 in the fascia of patients with incisional or recurrent incisional hernias. Samples of healthy skin or stable skin scar in patients without hernias served as controls. Altogether, our data indicated a significantly decreased ratio of collagen I/III in the fascia of patients with incisional hernias and recurrent incisional hernias. Furthermore, in these patients the expression of MMP-1 was decreased compared to the controls, whereas MMP-13 could not be detected in any fascia sample, with or without hernias present. For the first time, our results give evidence of the existence of a possible collagen disorder in these patients. The decreased ratio of collagen I/III is explainable due to a relative increase of collagen type III, which is known to be characterized by thin fibril diameters and lowered mechanical strength. The altered collagen ratio might be the result of the decreased activity of MMP-1, whereas the absent MMP-13 expression did not seem to modify the scar formation. Thus, our data indicate the presence of collagen metabolic disorders in patients with incisional hernias and recurrent incisional hernias. Furthermore, these results might explain the poor results of a mesh-free hernia repair, which again builds up scar tissue of inadequate collagen composition and strength.     

Collagen I/III and matrix metalloproteinases (MMP) 1 and 13 in the fascia of patients with incisional hernias.

The late appearance ofincisional hernias several years after laparotomy and the high recurrence rates after operation strongly imply the presence of a disorder of the connective tissue, although a specific defect in patients with incisional hernias has not yet been identified. In the present study we used both immunohistochemistry and Western blot analysis to evaluate the ratio of collagen I and III and the expression of the metalloproteinases (MMP) 1 and 13 in the fascia of patients with incisional or recurrent incisional hernias. Samples of healthy skin or stable skin scar in patients without hernias served as controls. Altogether, our data indicated a significantly decreased ratio of collagen I/III in the fascia of patients with incisional hernias and recurrent incisional hernias. Furthermore, in these patients the expression of MMP-1 was decreased compared to the controls, whereas MMP-13 could not be detected in any fascia sample, with or without hernias present. For the first time, our results give evidence of the existence of a possible collagen disorder in these patients. The decreased ratio ofcollagen I/III is explainable due to a relative increase of collagen type III, which is known to be characterized by thin fibril diameters and lowered mechanical strength. The altered collagen ratio might be the result of the decreased activity of MMP-1, whereas the absent MMP-13 expression did not seem to modify the scar formation. Thus, our data indicate the presence of collagen metabolic disorders in patients with incisional hernias and recurrent incisional hernias. Furthermore, these results might explain the poor results of a mesh-free hernia repair, which again builds up scar tissue of inadequate collagen composition and strength.     

Use of polypropylene mesh for incisional hernia repair

Incisional hernia is an important complication of abdominal surgery. Procedures for the repair of these hernias with sutures and with mesh have been reported, but there is no consensus about which type of procedure is best. We have performed a retrospective analysis on 1014 patients operated on in our unit between 1994 and 2003 for simple or recurrent incisional hernias. The polypropylene mesh has been used in a number of 107 patients. The mesh has been placed either intraperitoneal, extraperitoneal/subfascial or onlay. Median follow-up was 36 months. There were 1 enterocutaneous fistula and 5 wound sinus developed. The mesh had to be removed in 6 cases. All of these complication developed when the mesh has been placed either extraperitoneal/subfascial or onlay. We note 5 recurrent incisional hernias after a period of up to 24 months. The recurrence rates after open mesh repair are less then after primary closure. The intraperitoneal use of polypropylene mesh with omental coverage is a good procedure with less complications.     

Extraperitoneal prosthesis repair in the surgical treatment of inguinal hernias

The authors analyse the current state of the art of the prosthetic repair of incisional hernia and the problems involved in positioning the prosthesis, comparing their own experience with the most recent literature. From January 1994 to June 2001, 50 patients were operated on for incisional hernia (28 males and 22 females); 12% had recurrent or re-recurrent incisional hernias. Defects smaller than 3 cm were repaired with a polypropylene plug; a double-layer polypropylene mesh placed in a preperitoneal position was used for defects measuring from 3 to 5 cm; in defects greater than 5 cm a double-layer mesh was placed behind the muscle layer. Fifteen patients were operated on under local anaesthesia. Only 22% required postoperative analgesia. The mean hospital stay was 3.95 days. Only 3 recurrences (6%) were recorded. On the basis of our experience it seems appropriate to repair incisional hernias when of small size, preferably under local anaesthesia, avoiding opening the hernia sac, using an extraperitoneal approach with an overlap technique that employs polypropylene.     

Incisional hernia—comparison of mesh repair with Cardiff repair: an university hospital experience

Background: Incisional hernia is a frequent complication of abdominal surgery. Various types of repair are recommended for incisional hernia. Suture and mesh repair are compared in the present study. Method: One hundred seventy one patients with incisional hernia underwent Cardiff repair (far and near sutures with reinforcement sutures) which was used as an open suture repair while onlay polypropylene mesh was used in the mesh repair technique. Result: Cardiff repair was performed in 116 patients with no mortality with recurrence in two patients with mean follow up of 7.1 years. Both these patients with recurrence had a defect measuring more than 10 cm in width. Mesh repair was carried out in 55 patients with no recurrence in mean follow up of 37 months. Seroma formation was noted in 7 (12.72%) with mesh repair as compared to 4 (3.44%) patients with Cardiff repair. Conclusion: We recommend Cardiff repair for primary and small to medium size incisional hernias. Onlay polypropylene mesh is ideal for tension-free hernia repair, recurrent incisional hernia and hernia defects wider than 10 cm.     

Primary closure of laparotomies with high risk of incisional hernia using prosthetic material: analysis of usefulness

Incisional hernia continues to be a serious postoperative complication in abdominal surgery. We present a prospective randomised study to evaluate the usefulness of placement of a supra-aponeurotic polypropylene mesh in the primary closure of laparotomies with a high risk of incisional hernia. Closure of a vertical laparotomy in 100 patients was accomplished with continuous suture using non-reabsorbable material, with placement of a polypropylene mesh on the aponeurotic surface in 50 patients. Three years after surgery, five patients in the group without the mesh had suffered incisional hernia. No incisional hernia was detected in the group in which closure was made using the mesh (P=0.02). Use of prosthetic material (polypropylene mesh) in the primary closure of laparotomies with a high risk of incisional hernia is useful for reduction of the rate of incisional hernias.     

Use of polypropylene prostheses for strangulated inguinal and incisional hernias

We used monofilament polypropylene prostheses in 20 emergency operations for strangulated hernias. Sixteen of the operated patients had groin hernias (five of them recurrent), two had incisional and one had a Spigel's type hernia. Intestinal resection was performed because of bowel wall necrosis in one of the patients. During the postoperative period, we observed only one minor complication (a seroma formation). During the follow-up, no recurrence was observed. In our opinion, the use of monofilament polypropylene mesh in emergency hernia operations is safe, simple and effective. Electronic Publication     

Preliminary results of a two-layered prosthetic repair for recurrent inguinal and ventral hernias combining open and laparoscopic techniques

The use of prosthetic mesh has become the standard of care in the management of hernias because of its association with a low rate of recurrence. However, despite its use, recurrence rates of 1% have been reported in primary inguinal repair and rates as high as 15% with ventral hernia repair. When dealing with difficult recurrent hernias, the two-layer prosthetic repair technique is a good option. In the event of incarcerated or strangulated hernias, however; placement of prosthetic material is controversial due to the increased risk of infection. The same is true when hernia repairs are performed concurrently with potentially contaminated procedures such as cholecystectomy, appendectomy, or colectomy. The purpose of this study is to report our preliminary results on the treatment of recurrent hernias by combining laparoscopic and open techniques to construct a two-layered prosthetic repair using a four ply mesh of porcine small intestine submucosa (Surgisis®, Cook Surgical, Bloomington, IN, USA) in a potentially infected field and a combination of polypropylene and ePTFE (Gore-Tex®, W.L. Gore and Associates, Flagstaff, AZ, USA) in a clean field. From September 2002 to January 2004, nine patients (three males and six females) underwent laparoscopic and open placement of surgisis mesh in a two layered fashion for either recurrent incisional or inguinal hernias in a contaminated field. A total of eight recurrent hernia repairs were performed (five incisional, three inguinal) and one abdominal wall repair after resection of a metastatic tumor following open colectomy for colon carcinoma. Six procedures were performed in a potentially contaminated field (incarcerated or strangulated bowel within the hernia), two procedures were performed in a contaminated field because of infected polypropylene mesh, and one was in a clean field. Mean patient age was 56.4 years. The average operating time was 156.8 min. Operative findings included seven incarcerated hernias (four incisional and three inguinal), one strangulated inguinal hernia, and one ventral defect after resection of an abdominal wall metastasis for a previous colon cancer resection. In two of the cases, there was an abscess of a previously placed polypropylene mesh. All procedures were completed with two layers of mesh (eight cases with surgisis and one with combination of polypropylene/ePTFE). Median follow up was 10 months. Complications included two seromas, one urinary tract infection, two cases of atelectasis and one prolonged ileus. There were no wound infections. The average postoperative length of stay was 7.8 days. There have been no mesh-related complications or recurrent hernias in our early postoperative follow-up period. The use of a new prosthetic device in infected or potentially infected fields, and the two-layered approach shows promising results. This is encouraging and provides an alternative approach for the management of difficult, recurrent hernias.     

Fibroblasts from the transversalis fascia of young patients with direct inguinal hernias show constitutive MMP-2 overexpression

OBJECTIVE: To determine the expression pattern of certain metalloproteinases (MMPs) known to be involved in the degradation of the extracellular matrix in cultured fibroblasts from the transversalis fascia (TF) of patients with inguinal hernia. SUMMARY BACKGROUND DATA: Inguinal hernia is a common pathology, the cause of which remains unknown. It is, however, clear that the TF is one of the anatomical structures that may impede the formation of hernias, and particularly the direct type of hernia. In previous studies the authors found enhanced MMP-2 expression in TF specimens in vivo. The persistence of increased expression in cultured fibroblasts might support the idea of a genetic defect as the cause for this pathology. METHODS: Fibroblasts from the TF of patients with direct and indirect inguinal hernia were cultured and compared with those obtained from control TF in terms of MMP (MMP-2 and MMP-9) expression. RESULTS: Significant active MMP-2 expression was shown by TF fibroblasts from young patients with direct hernias. These findings were confirmed by immunosorbent assay, immunoblotting, and zymography of the fibroblast culture media. No MMP-9 expression was detected. CONCLUSION: These results indicate that MMP-2 may be involved in the TF matrix degradative process in patients with direct hernia. The persistence of changes in MMP-2 levels in the cell cultures appears to suggest a genetic defect or irreversible change as the origin of this pathology rather than environmental factors, which may later participate in the development of the hernial process.     

Central rupture and bulging of low-weight polypropylene mesh following recurrent incisional sublay hernioplasty

A recurrent incisional hernia resulting from the rupture of low-weight polypropylene mesh is rarely reported in the literature. Three patients with recurrent incisional hernia due to low-weight polypropylene mesh central rupture were operated 5, 7 and 13 months after initial sublay hernioplasty. The posterior myofascial layer was fully reconstructed in all patients during the hernioplasty, whereas the anterior myofascial layer was only partially reconstructed. The recurrent hernia was managed using heavy-weight polypropylene mesh; in two patients, a new sublay hernioplasty was performed and in one patient an “open preperitoneal flat mesh technique” was performed under local anaesthesia as a day case procedure. If closing of the anterior myofascial layer cannot be ensured during the incisional hernioplasty, the use of low-weight polypropylene meshes should be avoided; preference should be given to the heavy-weight polypropylene meshes.     

Laparoscopic Incisional Hernia Repair in Liver Transplant and Other Immunosuppressed Patients

We report the early results of laparoscopic incisional hernia repair in a small group of immunosuppressed patients and compare these results with a cohort of patients with open repair. We describe a modification used to secure the cephalad portion of the Gore-Tex mesh in high epigastric incisional hernias often encountered after liver transplantation. Data were gathered retrospectively for all incisional hernia repairs by our group from March 1996 to January 2001. Twelve of 13 attempted patients had successful completion of their laparoscopic hernia repairs with no reported recurrences to date. Two of these procedures were performed for recurrent hernias. We completed nine of nine attempted laparoscopic hernia repairs in liver transplant patients with epigastric incisional hernias. We repaired two of three attempted lower midline incisional hernias in renal disease patients. One of these patients was soon able to reuse his peritoneal dialysis catheter. A total of 15 patients, 12 with liver transplants, underwent open repair of their incisional hernias. These patients had seven recurrences and/or serious mesh infections with five patients electing repeated operations. In our initial series, laparoscopic mesh repair of incisional hernias is practical and safe in the abdominal organ transplant population with a low incidence of early recurrence and serious infections.     

Analysis of collagen-interacting proteins in patients with incisional hernias

BACKGROUND: In recent years a disorder of the collagen metabolism has been suggested for the pathogenesis of abdominal wall hernias. Previous investigations of skin specimens revealed a reduction in the collagen I/III ratio and alterations in matrix metalloproteinases in patients with incisional hernias. We investigated known collagen-interacting proteins to further characterize connective tissue in these patients. PATIENTS AND METHODS: Skin scars from patients with either primary or recurrent incisional and recurrent inguinal hernias, as a subgroup of incisional hernias, were analyzed for overall collagen content and for the distribution of collagen types I and III by crosspolarization microscopy. The expression of collagen type V, collagen receptor discoidin domain receptor 2, matrix metalloproteinase 1, connective tissue-like growth factor, and tenascin was determined by immunohistochemistry. Mature abdominal skin scars from patients without evident hernia served as controls. RESULTS: Patients with recurrent incisional hernia showed lowest ratios of collagen types I to III. Contents of overall collagen and of collagen type V did not differ between the groups. In patients with either primary or recurrent incisional hernias the proportion of collagen receptor discoidin domain receptor 2 positive cells was increased. Matrix metalloproteinase 1 expression was more pronounced in patients with recurrent incisional or inguinal hernias than in controls. Connective tissue-like growth factor was significantly increased in recurrent inguinal hernia patients. The expression of tenascin was notably decreased in all hernia groups. CONCLUSIONS: The observed alterations in the expression of collagen-interacting proteins again indicate the possibility of a fundamental connective tissue disease as the causal factor in the pathogenesis of (recurrent) incisional hernias.     

Randomized clinical trial comparing lightweight composite mesh with polyester or polypropylene mesh for incisional hernia repair

BACKGROUND: Polymer mesh has been used to repair incisional hernias with lower recurrence rates than suture repair. A new generation of mesh has been developed with reduced polypropylene mass and increased pore size. The aim of this study was to compare standard mesh with new lightweight mesh in patients undergoing incisional hernia repair. METHODS: Patients were randomized to receive lightweight composite mesh, or standard polyester or polypropylene mesh. Outcomes were evaluated at 21 days, 4, 12 and 24 months from patient responses to the Short Form 36 (SF-36) and daily activity questionnaires. Complications and recurrence rates were recorded. RESULTS: A total of 165 patients were included in an intention-to-treat analysis (83 lightweight mesh, 82 standard mesh). Postoperative complication rates were similar. The overall hernia recurrence rate was 17 per cent with the lightweight mesh versus 7 per cent with the standard mesh (P = 0.052). There were no differences in SF-36 physical function scores or daily activities between 21 days and 24 months after surgery. CONCLUSION: The use of the lightweight composite mesh for incisional hernia repair had similar outcomes to polypropylene or polyester mesh with the exception of a non-significant trend towards increased hernia recurrence. The latter may be related to technical factors with regard to the specific placement and fixation requirements of lightweight composite mesh.     

Incisional hernia repair after orthotopic liver transplantation: a technique employing an inlay/onlay polypropylene mesh

Background: The literature provides no data on the incidence and operative management of incisional hernias developing after orthotopic liver transplantation. The use of high-dose immunosuppressive agents results in an appreciable delay in wound healing. There is thus a need for a procedure for the reconstruction of the abdominal wall for patients on immunosuppression. The aim of this retrospective study was to establish the incidence of incisional hernias and an analysis of the results after implantation of a polypropylene mesh in inlay–onlay technique after liver transplantation is given.Methods: The basis for the present retrospective investigations was a total of 207 liver transplantations carried out in 192 patients (15 re-transplantations). After performing tensiometry, a polypropylene mesh (Marlex) was implanted to close the hernias using the inlay/onlay technique or a direct closure of the fascia was done. All treated hernias were followed up for a median of 18 months.Results: Among 184 patients, 17 developed incisional hernias after primary direct closure of the abdominal wall, giving an incidence of 9%. In an additional 8 patients an incisional hernia was seen where an absorbable mesh was used to close the abdominal wall after liver transplantation. In addition, there were 25 incisional hernias after 207 liver transplantations (12%). One of 15 (7%) of the surgically repaired hernias with implantation of a polypropylene mesh (Marlex) developed a recurrence. All the 3 patients after direct apposition of the fascia without using a polypropylene mesh suffered a recurrence (3 of 3; 100%). Significant risk factors for developing an incisional hernia were the amount of ascites and the stay in the ICU after transplantation. Neither severe deep nor superficial wound infection nor bowel fistulas were observed after implantation of a inlay/onlay mesh.Conclusion: In patients after liver transplantation, the implantation of a polypropylene mesh proved to be an efficient and safe method of treating incisional hernias. Implantation of a mesh was not associated with an increased infection rate, despite the use of immunosuppression. In view of the high recurrence rate associated with primary closure, mesh implantation should be given preference.     

补片修补腹壁切口疝的临床应用

目的探讨腹壁切口疝的治疗。方法回顾性分析150例腹壁切口疝患者的临床资料。（1）肌腱膜上补片置入手术（ONLAY）126例；（2）筋膜前（腹膜前）、肌下补片置入手术（SUBLAY）4例；（3）缺损处直接补片置入途径（INLAY）13例；（4）腹膜腔内补片置入术（Introperitonealsite）7例。结果平均年龄58．5岁，女性占52．5％。上腹部切口36％，下腹部切口占64％。全部采用合成材料修补。聚丙烯材料130例，聚四氟乙烯-聚丙烯双面材料16例，强生Proceed补片4例，开腹手术143例，腹腔镜手术7例。复发3例，手术复发率为2％。结论ONLAY手术安全可靠，复发率低，是可以接受的切口疝修补方法，避免伤口感染，防治腹内压升高，促进伤口愈合，保证缝合质量是预防切口疝关键。     

Late results of mesh wound closure after elective open aortic aneurysm repair.

INTRODUCTION: Incisional hernia is a common late complication after abdominal aortic aneurysm (AAA) repair. We examined the outcome after prophylactic placement of a pre-peritoneal polypropylene mesh during abdominal closure in consecutive patients having elective AAA repair. REPORT: At least 30 months after surgery, 28 patients underwent clinical and ultrasound examination of their surgical wound for incisional hernias. Only one patient had a hernia in the original surgical scar. No patients had late mesh-related wound problems. DISCUSSION: Pre-peritoneal polypropylene mesh placement is a simple, safe and effective method to decrease the incidence of incisional hernia after AAA repair.     

The use of an underlay polypropylene mesh in complicated incisional hernias: sucessful French surgical technique

BACKGROUND: Incisional hernia repair with conventional techniques is associated with high recurrence rates of 30-50%. Surgical repair using different prosthetic biomaterials is becoming increasingly popular. On the basis of the favourable results by French surgeons, the results of underlay prosthetic mesh repair using polypropylene mesh in complicated and recurrent incisional hernias have been studied. METHODS: After preparation and excision of the entire hernia sac, the peritoneum and posterior rectus sheath are closed with a continuous looped polyglyconate suture. The prosthesis used for the midline hernias is positioned on the posterior rectus sheath and extends far beyond the borders of the myoaponeurotic defect. The prosthesis for lumbar and subcostal hernias is placed in a prepared space between the transverse and oblique muscles. Intraperitoneal placement of the mesh must be avoided. Between January 1997 and September 1998 a total of 57 incisional hernia repair (25 primary hernias, 32 recurrent hernias) have been performed using this technique (28 women, 29 men, mean age 56+/-13 years). RESULTS: Local complications occurred in 6 patients (11%). One patient suddenly died on the 3rd postoperative day from severe pulmonary embolism (mortality 1,7%). Thirthy-seven patients with a minimum follow-up of 6 months were reexamined clinically (follow up time 6-33 months). Till now one recurrent hernia has been observed. There were only minor complaints like a feeling of tension in the abdominal wall (n = 3) and slight pain under physical stress (n = 9). CONCLUSIONS: The aforementioned technique of underlay prosthetic repair allows an anatomical and consolidated reconstruction of the damaged abdominal wall with excellent results and low complication rates especially in high risk patients and complicated hernias.     

Randomized clinical trial of suture repair, polypropylene mesh or autodermal hernioplasty for incisional hernia

BACKGROUND: Since conventional suture repair for incisional hernia is associated with high recurrence rates, alloplastic and autoplastic prosthetic techniques have been suggested. METHODS: In a randomized trial, 160 patients with simple or complex hernias underwent either suture repair, autodermal skin graft or onlay polypropylene mesh repair. Suture repair was not done in complex hernias. This report concerns a planned interim analysis. RESULTS: At mean follow-up of 16 months, there were 17 hernia recurrences that were distributed similarly between the surgical techniques. There were fewer infectious complications after suture repair (three of 33 patients) than after skin graft or mesh repair (seven of 39 and five of 28 for simple hernias; seven of 31 and ten of 29 respectively for complex hernias) (P not significant). The severity of infections after polypropylene mesh implantation prompted the trial committee to discontinue the study. No differences were noted in duration of stay in hospital and quality of life. However, pain was significantly more frequent after polypropylene mesh repair (pooled risk ratio 2.9 and 1.8 at 6 weeks and 1 year respectively). CONCLUSION: Suture repair was safe for small incisional hernias. Both autoplastic and alloplastic hernia repair yielded comparably low recurrence rates, but led to a high rate of wound infection.