Classification and surgical treatment of incisional hernia. Results of an experts' meeting.

BACKGROUND: The treatment of incisional hernia (IH) is a current problem in modern surgery. Many important aspects of incisional hernia surgery are yet to be answered, especially the choice of surgical technique and its adaptation to the individual patient. The aim of this experts' meeting was to resolve some current questions in incisional hernia surgery and to organise an international hernia register. METHODS: An international panel of ten experts met under the auspices of the European Hernia Society (GREPA) to investigate the classification and therapeutic alternatives for incisional hernia. Prior to the conference, all experts were asked to submit their arguments in the form of published results. All papers received were weighted according to their scientific quality and relevance. The information from this correspondence was used as a basis for panel discussion. The personal experiences of the participants and other aspects of individualised therapy were also considered. RESULTS: The expert panel suggested a new classification of incisional hernia based on localisation, size, recurrences and symptoms. All experts agreed that the fascia duplication and the fascia adaptation should only be used for small incisional hernias. Fascia duplication is of value only in the horizontal direction. The technical details and the pros and cons of each procedure were discussed for prosthetic implantation using onlay and sublay techniques and the technique of autodermal hernioplasty. CONCLUSIONS: The management of incisional hernia is currently not standardised. In order to answer relevant questions of incisional hernia surgery, an international hernia register should be established.

Experimental study on the in vivo behaviour of a new collagen glue in lung surgery.

OBJECTIVE: To study the pneumostatic ability of a collagen polymerised with a polysaccharide (GAO) glue in lung surgery; its influence in pleuro-pulmonary adhesion formation; the pulmonary tissue reaction to it, its biodegradability, and the eventual alterations of pulmonary compliance induced by the glue. METHODS: Two groups of ten rabbits (controls and treated) were operated under ventilatory assistance by thoracotomy to promote pleural adhesions, and injury to the lung. Repeated chest X-rays were carried out postoperatively. Lungs were examined histologically at day 40. In vitro tests were performed to study glue effects on pulmonary compliance. RESULTS: Air leaks stopped 2 min after glue application. Persistent pneumothorax were likely seen in treated rabbits (ns). Glue induces a temporary reduction of pulmonary compliance. Glue did not increase adhesion formation, or interfere with the healing process. CONCLUSIONS: For its properties, GAO seems to be a good and well-tolerated tool to reduce air leaks from the lung, without inducing residual pleural symphysis.

Carboxymethyl benzylamide dextran blocks angiogenesis of MDA-MB435 breast carcinoma xenografted in fat pad and its lung metastases in nude mice.

We previously showed that carboxymethyl benzylamide dextran (CMDB7) prevents tumor growth and tumor angiogenesis by binding to angiogenic growth factors, thereby preventing them from reaching their receptors on tumor or stromal cells (Bagheri-Yarmand et al. Br. J. Cancer, 78: 111-118, 1998; Bagheri-Yarmand et al. Cell Growth Differ., 9: 497-504, 1998). In this study, CMDB7 inhibited neovessel formation within the fibroblast growth factor 2-enriched matrigel in mice, and its anticancer effect was then tested in a metastatic breast cancer model. Human MDA-MB435 cells were injected into the mammary fat pad of nude mice, and breast tumors developed within 1 week; all of the mice had lung metastases at 12 weeks. CMDB7 treatment (50, 150, or 300 s.c. or 300 i.v. mg/kg/week for 10 weeks) reduced the incidence of lung metastases to 12%. Histological analysis showed markedly less tumor neovascularization in the CMDB7-treated mice. Pulmonary metastasis incidence was strongly dependent on the intratumoral neoangiogenesis in primary tumors.

Replacement of a tracheal segment by a mixed graft (aorta and prosthesis): an experimental study in rabbits.

OBJECTIVE: To develop a new graft and to verify its technical feasibility, viability, and ability to reduce the risk of infection by interposition of an aortic segment between the airway and the prosthetic component of the graft. DESIGN: Experimental study. SETTING: Multicentre study, France. ANIMALS: 38 New Zealand rabbits. INTRODUCTION: A 1 cm aortic segment was obtained from the thoracic aorta of a rabbit and cryopreserved or stored at +4 degrees C. The aortic segment, surrounded by a ringed expanded polytetrafluoroethylene (ePTFE) prosthesis was used to replace 1 cm of cervical trachea in two groups of rabbits, either with cryopreserved or fresh aorta. MAIN OUTCOME MEASURES: Macroscopic, microbiological, and histological studies four months later. RESULTS: 12/20 animals in the cryopreserved group survived and 13/18 in those had had fresh aorta inserted. Partial or total necrosis of the aortic muscular layer was replaced by connective tissue, which was a guide for epithelialisation from the anastomoses. CONCLUSION: This new graft is worthy of further investigation, as it is technically feasible and easy to insert.

The abdominal linea alba: an anatomo-radiologic and biomechanical study.

Traditionally, the linea alba represents the principal route of approach in abdominal surgery and in consequence it is the commonest site of incisional hernia. The aim of this study was to review its morphology and to study its mechanical parameters of resistance, deformation and elasticity in order to compare these with the prosthetic materials most often used in the treatment of incisional hernia. Forty fresh cadavers were dissected and tests with a dynamometer and "bursting strength tester" were performed on samples taken from the linea alba at three levels: supra-umbilical, subumbilical and umbilical. Forty abdomino-pelvic scans were analysed. The morphologic results allowed definition of diastasis of the rectus mm. in terms of subject age: below 45 years of age diastasis was considered as a separation of the two rectus mm. exceeding 10 mm above the umbilicus, 27 mm at the umbilical ring and 9 mm below the umbilicus; above 45 years of age the corresponding values were 15 mm, 27 mm and 14 mm respectively. In the biomechanical study the subumbilical region exhibited a coefficient of elasticity greater than that of the supra-umbilical portion, but no significant difference in resistance was found between the different parts studied. The biomechanical results are compared with the corresponding data for prosthetic materials.

[Abdominal wall prostheses. Biomechanic and histological study]. / Les prothèses pariétales abdominales. Etude biomécanique et histologique.

The best prosthetic material is one which provides the best mechanical resistance with the best biological tolerance. In order to assess the mechanical and histological properties of abdominal wall prostheses, we performed experimental tests in animal models comparing four materials: polypropylene, dacron, polyglactine 910 and a dacron-polyglactine 910 composite. One hundred thirty rabbits were used including 10 controls and 120 test animals. A medial laparotomy was closed with an antemuscular aponevrotic prosthesis in the test animals. Animals were sacrificed at one, two and three months after the operation. Abdominal wall and prosthesis samples were tested to determine resistance to pressure and extension, deformability and elasticity. Histology tests were also done to determine resistance quality and biological tolerance. Dacron was tolerated best and was less resistant than polypropylene, though resistance was satisfactory. There was no advantage with polyglactine compared with non-resorbable prostheses; its only indication would be a septic site. The composite material tested had a resistance comparable with that of dacron but was less well tolerated.

The venous drainage of the pancreas.

With the aim of clarifying certain contradictory aspects of the description of the venous drainage of the pancreas, a review of the literature and an anatomic study were carried out. Fifty duodeno-pancreatic blocks were studied by the injection-corrosion technique, of which 45 were available for study of the right pancreas and 37 for that of the left pancreas. The venous drainage of the duodeno-pancreas is effected via two territories: a posterosuperior and an anteroinferior, the former draining toward the portal v. and the second into the superior mesenteric v. The borderline between the two is represented by the inferior posterior pancreatico-duodenal (IPPD) v. Four veins ensure duodeno-pancreatic drainage: the superior anterior, inferior anterior, superior posterior and inferior posterior pancreatico-duodenal vv. (SAPD, IAPD, SPPD and IPPD). The major vein of the ventral aspect is the SAPD; that of the dorsal aspect is the SPPD. Two arches, anterior and posterior, were found in the majority of cases. The left pancreas drains into the splenic v. via several collateral branches. Other veins participate in the venous drainage of the isthmus, body and tail of the pancreas, including the inferior or transverse pancreatic v.

Radioanatomic study of the gastrocolic venous trunk.

The mode of formation, measurements and frequency of occurrence of the gastrocolic venous trunk were studied by the injection-corrosion technique in a series of 54 anatomic specimens and by the analysis of 50 CT studies in patients without hepatic or pancreatic disease. The gastrocolic trunk was found in 51 of the 54 anatomic specimens and in 27 of the 50 CT studies. The great variability in its formation, whether bipodal, tripodal or quadripodal, was noted. With a mean diameter of 4.9 mm, it opened into the anterior, right or antero-left aspects of the superior mesenteric v. at a mean distance of 15 mm below the inferior border of the spleno-mesenteric confluence. The value of preliminary CT assessment before an operation for portal hypertension or a pancreatic tumor or in the diagnosis of a splenic thrombosis is emphasised.

Anatomic basis of venous drainage in gastric tubular esophagoplasty.

This study was made with the aim of specifying the general architecture of the venous system of the stomach and its mode of drainage under normal conditions, and also of investigating the role of the venous drainage in the origin of disunion, anastomotic fistula and structure after tubular esophagoplasty pedicled on the right gastroepiploic vessels. Sixty stomachs removed from fresh cadavers were studied by injection-corrosion, using colored Altufix P10 as the injection mass. 35 specimens were injected globally via the superior mesenteric v., 15 by the same route but after clamping of the splenic, left gastric and right gastric vv., which corresponds to the technique of gastrolysis performed in esophagoplasty, and 10 were injected simultaneously with media of four different colors via the left gastric, right gastric, superior mesenteric and splenic vv. to define their respective territories. Also studied were the origin, course, termination, territory and caliber of the main gastric veins. Analysis of the results confirmed the richness of the venous anastomoses of the stomach, effected on the one hand between the two extraparietal arches at the greater and lesser curvatures, and on the other by intraperitoneal communications arranged perpendicular to these two arches. It emerges that the right gastroepiploic v. cannot always ensure drainage of the entire stomach. The factors involved are discussed. The risk of venous stasis in gastric esophagoplasty must always be borne in mind.

Anatomic basis of the physiopathology of the epicondylalgias: a study of the deep branch of the radial nerve.

Compression of the deep branch of the radial n. during its passage through Fröhse's arcade in the supinator m. is one of the classical explanations advanced for epicondylalgia. The object of this study was to define the anatomy of the deep branch of the radial n. from its origin up to the origin of the branches to the lateral epicondylar mm. 34 upper limbs were dissected and three segments of the deep branch of the radial n. were distinguished: segment I, from its origin to its entry into the supinator m.; segment II, corresponding to its passage through the supinator m.; and segment III, extending from its exit from the supinator m. to the origin of the nn. to the lateral epicondylar mm. The lengths of these three segments were defined, as well as the level of division of the radial n. in relation to the joint-line, the thickness of the arcade of the supinator m., and the number of nerve branches to the supinator m. It was found that segment III is closely related to the radial head, around which it winds in supination and extension. The three nerve segments thus defined were studied separately microscopically for evidence of lesions. The results were as follows. Segment I: absence of any marked histologic lesions; segment II: marked fibrous thickening of the perineurium and the interstitial connective tissue, replacing certain nerve fibers; segment III: persistence of moderate interstitial fibrosis. These findings appeared constant in all the specimens examined. These results indicate that the deep branch of the radial n. is most affected during its passage through the supinator m.(ABSTRACT TRUNCATED AT 250 WORDS)

Arterial vascularisation of the extrahepatic biliary tract.

The aim of this study was to establish a plan of the arterial distribution to the main supraduodenal biliary tract in order to draw practical conclusions for biliary surgery, especially in bilio-alimentary and bilio-biliary anastomoses and liver transplantation. It was based on a study of 60 fresh subjects and was carried out using four different methods: dissection after injection of colored latex into the superior mesenteric a. (10 subjects), radiography and dissection after injection of Micropaque into the celiac trunk (10), dissection after injection of Indian ink into the common hepatic a. (10) and radiography and dissection after selective injection of the right hepatic a. or the gastroduodenal a. (30). Analysis of the results leads to definition of three types of vascularisation and two territories, superior and inferior, overlapping at the level of the mouth of the cystic duct. The practical implications for biliary surgery and liver transplantation are discussed.

Perceptual processing and speed-accuracy trade-off.

Three experiments are described on speed-accuracy trade-off during a visual fixation. In a typical trial subjects started by fixating a fixed position at their left side at which a degraded digit (SL) was presented. At about the same time an intact digit (SR) was briefly presented at a fixed right side position. SL and SR were separated by a binocular visual angle of 45 degrees. The task was to verbally report both digits, which implied that the eyes should be rapidly shifted from SL to SR, so as not to miss SR. Under these conditions the distribution of the fixation latencies of SL appeared to consist of two parts, suggesting the occurrence of either anticipations or reactions. This argues against a strategy of optional stopping of information accrual during the fixation of SL and is in line with a strategy of either fully neglecting or fully encoding SL. However, this interpretation meets the difficulty that, at trials where SL is reacted to, subjects showed a shorter fixation latency than in a control condition, in which they had ample time to view both SL and SR. The results of the second and third study supported the view that, when under time stress, subjects can end a fixation as soon as a preliminary code of SL is obtained. This code (a) is insensitive to the complexity of SL, (b) cannot be elaborated during the saccade to SR, and (c) can be used as a starting point for further analysis, as soon as the eyes reach SR.