[The use of mesh in abdominal wall defects]

Today abdominal wall defect repair can't prescind from the use of prosthetic materials. Inguinal, femoral and incisional hernias represent more frequent events in which, only using prosthetic materials is it possible to perform "tension-free" repair. Prosthetic repairs "agree with" abdominal, wall physio-pathology, guarantee results and prevent recurrences. Permanent biomaterials like polypropylene and dacron mesh deserve special attention for their distinctive features are suitable for abdominal wall defect repair. Selection of material is an important step according to surgical technique and to avoid complications; the most alarming of which is a possible infection. However the average incidence of infection on prosthesis is about 0.5%. While infection risk is really scarce, the benefits of prosthetic repairs are clear: the recurrence rate of traditional hernia repairs is about 33% and 0-0.7% in prosthetic repairs. Likewise the recurrence rate for traditional incisional hernia repair is between 14% and 50%, whereas in prosthetic repairs it is 0-4.5%. Therefore it is necessary to use prosthesis for the following two reasons: firstly to avoid tension on the suture line, the prime cause of recurrence, and secondly to increase formation of collagen fibres on the transversalis fascia that appears histologically and biochemically altered. The authors report their experience of 660 prosthetic repairs, 600 for hernia and 60 for incisional hernia, performed, in the period April 1992-December 1994, at the General Surgery Department in San Giovanni Valdarno Hospital. The surgical techniques used were "tension-free" and "sutureless" and the prosthesis laid down always a polypropylene mesh. Complications only occurred in 33 patients, particularly 4 cases of infection (0.6%) however mesh remove was not required. The follow-up until today evidenced only two early recurrences owing to our technical mistakes in the beginning of our experience. For incisional hernia repair we laid down a giant dacron mesh on preperitoneal space. No complications were registered. The average stay in hospital was 5 days and follow-up showed no recurrence. The use of prosthetic materials in abdominal wall defect repair expressed large benefits with evident and clear reduction in recurrence rate. Traditional techniques produce tension on the suture line and high percentage of early and late recurrences since an essential surgical principle is transgressed. In fact traditionally repair has been accomplished by approximation of anatomical structures, that are not normally in apposition and by utilization of defective tissue. Metabolic alteration involving collagen turnover is evident in these patients. The answer to this problem is prosthetic repair. At present there is no ideal prosthesis, however the surgeon can use several suitable synthetic materials. The selection of prosthetic materials is a fundamental step also considering the possible infection; that however develops rarely. In conclusion the authors think that mesh repairs represent an overcoming of traditional surgical techniques in abdominal wall defect repair.