Correspondence perform an initial colectomy and ileostomy with preservation of the rectal stump. The pathological report of the surgical specimen confirmed ulcerative colitis, and no dysplasia was found. One year later the rectovaginal and perianal fistulae had healed and the patient underwent restorative protectomy with a protective ileostomy. After mucosectomy of a long (6-7-cm) rectal cuff, an S shaped ileal reservoir was hand-sutured to the dentate line. Recovery was uneventful, apart from an episode of small bowel obstruction that required laparotomy 2 months later. The ileostomy was closed 3 months after the pouch procedure. As commonly seen in those with an S shaped reservoir with a long efferent limb, the patient needed to catheterize the pouch, but this has been a regular and uneventful practice during the past 13 years. Pouchitis did not develop. In June 1990 the patient developed a pouch-vagmal fistula and 1 month later underwent laparotomy, at which no fistular track was detected on dissecting the pouch from the posterior wall of the vagina. Symptoms and signs recurred 14 months later, the external opening of the fistula being 7 cm from the fourchette. Pouch-vaginal fistulation is a major complication of restorative proctocolectomy, the incidence being between 7 and 14 per cent in series from different centres'.'. It may develop early before ileostomy closure or, more commonly, a few months after. The vast majority of these occur at the ileoanal anastomotic level. Aetiological factors in our experience may include extensive rectovaginal dissection, a short rectal cuff and a stapled anastomosis. Treatment is difficult and local procedures, irrespective of the technique employed, fail in about half of cases. Resuturing the anastomosis does not seem to offer better results. The best outcome is achieved in pouch-vaginal fistulae occurring before ileostomy closure. Ultimately in one-third of cases the pouch has to be excised. This is the first report of late onset of a pouch-vaginal fistula. In this case chronic trauma from self-catheterization of the pouch may have been the cause. P. S. Carraro
R. J. Nicholls J. Groom St Mark's Hospital City Road London ECI V 2PS UK
Wexner SD, Rothenberger DA, Jensen L el al. Ileal pouch-vaginal fistula: incidence, etiology and management. Dis Colon Rectum 1989; 32: 460-5. Keighley MRB, Asperer J, Hosie K, Grobler S. Fistula complicating restorative proctocolectomy. Gut 1991; 32: A557-A558.
Seeding of human microvascular endothelial cells onto polytetrafluoroethylene graft material Sir We were interested to read the paper by Stansby et al. (Br J Surg 1991; 78: 1189-92). The authors argued that since both endothelial and mesothelial cells are suitable for vascular cell seeding, the true origin of these cells might be academic. The assumption that mesothelial cells may also protect the seeded vascular graft against unwanted thrombosis is based on reported observations of non-thrombogenic properties like tissue plasminogen activator synthesis and prostacyclin production of these cells'.'. However, human mesothelial cells do also express procoagulant activity. In vitro experiments have shown that isolated and cultured mesothelial cells express tissue factor, the activator of the extrinsic pathway of the coagulation cascade. This is one of the known differences between mesothelial and endothelial cells. Therefore, in our opinion, cells harvested from the omental fat should be characterized. Mesothelial cells are identified by staining with monoclonal antibodies directed against cytokeratins 6 and 18, an immunofluorescence staining procedure that can be performed in every laboratory3. Expression of cytokeratins by endothelial cells has never been reported. Because a cobblestone appearance in culture, uptake of diacetylated low-density lipoprotein, and positive immunofluorescent staining for von Willebrand's factor used by Stansby et al. are also properties of mesothelial cells, the characterization of endothelial cells by these features is far from reliable4. With the use of immunofluorescence staining with monoclonal antibodies for cytokeratins, it is now generally accepted that cobblestone cells derived from omental
Br. J. Surg., Vol. 79, No. 7, July1992
fat tissue are not endothelial but mesothelial in rigi in^.^. To prevent further confusion and to stimulate more studies on the suitability of omental cells for vascular cell seeding, reliable characterization of these cells should be undertaken. A. Pronk P. Leguit Academisch Ziekenhuis Utrecht Utrecht The Netherlands 1.
Speiser W, Anders E, Preisdsner KT, Wagner 0, Muller Berghaus G. Differences in coagulant and fibrinolytic activities of cultured human endothelial cells derived from omental tissue microvessels and umbilical veins. Blood 1987: 3: 964-7. Bull HA, Pitillo RM, Drury J et al. Effects of autologous mesothelial cell seeding on prostacyclin production within Dacron arterial prosthesis. Br J Surg 1988; 75: 671-4. Wu YJ, Parker LM, Beckett MA. The mesothelial keratins: a new family of cytoskeletal proteins identified in cultured mesothelial cells and nonkeratinizing epithelia. Cell 1982; 31:693-703. Visser MJT, Van Bockel JH, Goos N P et al. Cells derived from omental fat tissue and used for seeding vascular prostheses are not endothelial in origin. J Vasc Surg 1991; 13: 373-81. Takahashi K, Goto T, Mukai K et al. Cobblestone monolayer cells from the human omental adipose tissue are possibly mesothelial, not endothelial. In Vitro Cell Deu Biol 1989; 25: 109-11.
Surgical implications of drug-induced rha bdomyolysis Sir We read with interest the paper by Rutgers et al. (Br JSurg 1991; 78: 490-2) in which four cases of acute drug-induced rhabdomyolysis with secondary compartment syndromes are described. We agree that drug-induced toxic rhabdomyolysis is uncommon and that many cases are associated with coma which may cause secondary muscle damage. The few drugs that have been implicated in causing direct toxic rhabdomyolysis include alcohol, barbiturates and other psychotropic drugs which have been reviewed comprehensively by Gabow et al.'. We recently reported a case of rhabdomyolysis and compartment syndrome secondary to theophylline overdose2. In the paper cited all the patients were alcoholics but no mention was made of delirium tremens, hypocalcaemia and the toxic effect of alcohol and benzodiazepines, all of which may contribute to rhabdomyolysis. Furthermore, there was no report of the serum levels of calcium, benzodiazepines or alcohol. Even though the authors rightly point out the value of monitoring compartment pressures, in none of the cases presented was the compartment pressure quoted. We would suggest that pressure monitoring is mandatory when a diagnosis of compartment syndrome is considered in a patient who is unwilling or unable to cooperate in eliciting clinical signs, and that full documentation of serum toxicology is essential when discussing the complications of drug overdose. S. P.K. Payne D. M. L. Lloyd University Department of Surgery Leicester Royal Injirmary Leicester LEI 5 WW UK 1.
Gabow PA, Kachny WE, Kelleher SP. The spectrum of rhabdomyolysis. Medicine 1982; 61: 141-52. Lloyd DML, Payne SPK, Tomson CRV, Barnes MR, Allen MJ. Acute compartment syndrome secondary to theophylline overdose. Lancet 1990: 335: 312.
Current management of trauma t o the pancreas Sir Messrs Wilson and Moorehead attempted an exhaustive review of the management of pancreatic trauma (Br J Surg 1991; 78: 1196-202). Unfortunately, certain laconic statements make the title 'current management' questionable.