Life table analysis of stomal complications following colostomy

PURPOSE

This study was designed to evaluate the long-term complication rate of left iliac fossa end sigmoid colostomies and to determine etiologic factors.

METHODS

A retrospective chart review and actuarial analysis were performed.

RESULTS

The crude and actuarial risks of paracolostomy complications in 203 patients were 51.2 percent and 58.1 percent at 13 years, respectively. Paracolostomy hernia was the most common complication (36.7 percent at 10 years). Siting the stoma through the belly of the rectus abdominis muscle did not reduce the risk of hernia, but an extraperitoneal course had a significantly lower risk of herniation when compared with a transperitoneal course and intestinal obstruction was marginally less frequent. Paracolostomy hernias were otherwise more likely in the elderly, and in those with other abdominal wall hernias. Mesenteric fixation did not reduce the subsequent chance of prolapse. The reduction in the risk of intestinal obstruction when lateral space closure was employed was not statistically significant (4 percent vs. 10 percent, P < 0.1), and all three patients with stomal retraction had had lateral space closure.

CONCLUSION

The evidence in this study that spans a 22-year period questions much surgical technical dogma and raises the possibility that parastomal hernias may, like inguinal hernias, represent a failure in the transversalis fascia that might technically be avoidable.

Detection of free malignant cells in the peritoneal cavity before and after resection of colorectal cancer

PURPOSE

This study was designed to select the best monoclonal antibody to stain malignant cells in peritoneal wash fluid, and to investigate the incidence of free malignant cells in preresection and postresection colorectal cancer peritoneal washings using a combination of conventional cytology and immunocytochemistry.

METHODS

Peritoneal washings were taken from 35 consecutive patients undergoing colorectal cancer resection.

RESULTS

Malignant cells were isolated on a density gradient and identified by conventional cytology and an indirect immunoperoxidase stain. Malignant cells were identified in peritoneal washings from 15 patients (preresection only n = 3, postresection only n = 4, both n = 8). The origin of free malignant peritoneal cells in 11 preresection-positive washings must be the serosa. The origin of these cells in the four postresection-positive patients is uncertain: serosal and luminal spillage were considered unlikely and no circulating cells were found in the mesenteric vessels near the tumor.

CONCLUSION

Tumor cells may have leaked out from lymphatics cut during the dissection.

Evidence for adenoma-carcinoma sequence in the duodenum of patients with familial adenomatous polyposis. The Leeds Castle Polyposis Group (Upper Gastrointestinal Committee)

AIMS

To explore the association between duodenal adenoma and carcinoma in patients with familial adenomatous polyposis (FAP).

METHODS

A multicentre survey of 1262 patients with FAP yielded 47 cases of duodenal cancer. The association between adenoma and cancer was assessed in these cases.

RESULTS

Adenomatous tissue was found within duodenal cancer in 29 of 44 (66%) patients with FAP and in mucosa adjacent to duodenal cancer in 31 of 42 (73%) such patients. Adenomas were found as a component of, or adjacent to, duodenal cancer in 38 of 45 (84%) patients.

CONCLUSIONS

These observations support the existence of the adenomacarcinoma sequence in the duodenum of patients with FAP. Factors associated with malignant change included villous histology, moderate or severe dysplasia, and the presence of stage IV duodenal polyposis.

Haemorrhoids: pathology, pathophysiology and aetiology

Haemorrhoidal disease is the consequence of distal displacement of the anal cushions, which are normal structures with an important role in continence. The causes of haemorrhoidal disease are unknown; constipation and abnormal bowel habit are commonly blamed despite largely contrary evidence. The most consistently demonstrated physiological abnormality is an increased maximum resting anal pressure. Most evidence points to this being a secondary phenomenon rather than the cause of haemorrhoidal disease. Among the many unexplored areas are the function of the longitudinal muscle in relation to haemorrhoidal disease, the description and pharmacological responsiveness of the anal subepithelial muscle, and the clinical role of specific pharmacological agents that might reverse some of the observed physiological changes.

Magnetic resonance imaging of fistula-in-ano

PURPOSE

Successful management of anal fistulas depends upon accurate assessment of the primary tract and any secondary extensions. Preoperative imaging has, to date, been disappointing.

METHODS

A prospective study of 35 patients with a clinical diagnosis of fistula-in-ano was performed comparing magnetic resonance imaging with the independently documented operative findings. Magnetic resonance imaging was also compared with anal endosonography in 20 patients.

RESULTS

Magnetic resonance imaging is accurate and demonstrates pathology missed at surgery by experienced coloproctologists. Magnetic resonance imaging is superior to anal endosonography.

CONCLUSIONS

Magnetic resonance imaging is advocated as the method of choice when imaging is required for anal fistulas.

Results of Delorme's procedure for rectal prolapse

PURPOSE

This study was designed to examine the results of Delorme's procedure.

METHODS

Thirty-two patients (24 males and 8 females, mean age, 70 years) underwent Delorme's procedure between 1978 and 1990 following symptoms lasting between two weeks and ten years. Thirteen patients had had 21 previous operations for prolapse.

RESULTS

The mean operation time was 65 minutes. No blood transfusions were needed, there was no operative mortality, and only two patients had complications (one chest infection and one anastomotic dehiscence). No patients were lost to follow-up. Over a mean follow-up of 24 months (4 months to 4 years), 9 patients died of unrelated conditions. There were four recurrences (12.5 percent), two in patients who had each had two previous procedures. Incontinence improved in 46 percent. No patient became constipated and 50 percent of those constipated preoperatively improved.

CONCLUSION

Although abdominal rectopexy is safe and has a low recurrence rate (< 5 percent), it involves the hazards of a laparotomy. In addition, up to 40 percent of patients become constipated after rectopexy which may be debilitating. Delorme's procedure has a low morbidity, results in good bowel function, and has a low recurrence rate. It can be performed on unfit patients with possible advantages over rectopexy and perhaps should be used more readily.

Life-table analysis of stomal complications following ileostomy

Stomal complications of ileostomy may occur many years after construction. An actuarial analysis of complications of 150 permanent end ileostomies constructed over a 10-year period is reported. By 20 years the incidence of stomal complications approached 76 per cent in patients operated on for ulcerative colitis and 59 per cent in those with Crohn's disease (P < 0.05). Revisional surgery rates were higher in patients with ulcerative colitis than in those with Crohn's disease (28 versus 16 per cent), albeit not significantly. The four commonest complications were skin problems (cumulative probability 34 per cent), intestinal obstruction (23 per cent), retraction (17 per cent) and parastomal herniation (16 per cent). Closure of the lateral space did not reduce the probability of developing intestinal obstruction (18 per cent at 20 years in those with closure versus 3 per cent in those without, P > 0.1). Fixation of the mesentery did not reduce the probability of developing prolapse of the ileostomy (11 per cent in those with fixation versus none in those without, P < 0.1). The incidence of parastomal herniation was not reduced by sitting through the rectus abdominis (21 per cent in those sited through the body of the rectus abdominis versus 7 per cent in those sited through the oblique muscles, P < 0.1). Some of the surgical dogmas relating to ileostomy construction are not supported by the results of this study.

Surgical assessment of acute anorectal sepsis is a better predictor of fistula than microbiological analysis

Twenty-two patients with acute anorectal sepsis were examined prospectively to compare surgical assessment with microbiological analysis as predictors of the aetiology of the sepsis. Culture of gut organisms was a sensitive method of detecting an underlying fistula but was not particularly specific (80 per cent). Demonstration of sepsis in the intersphincteric space in association with an anorectal abscess was 100 per cent sensitive and 100 per cent specific for detection of an underlying fistula. The demonstration was facilitated by a radially placed incision.

Ischaemic colitis in association with sigmoid carcinoma: a report of two cases

The association of ischaemic colitis with a distal obstructing carcinoma is described in two patients. When a segment of colonic ischaemia is demonstrated on barium enema, it is important to consider an association with a distal tumour.

Magnetic resonance imaging of fistula-in-ano: technique, interpretation and accuracy

The aim of this study was to document the appearances of fistula-in-ano on magnetic resonance imaging (MRI) and to prospectively evaluate the accuracy of MRI in the pre-operative assessment of anal fistulae. Patients with a clinical diagnosis of fistula-in-ano and awaiting surgery (n = 35) were examined with MRI. The fistulous tracks with their secondary extensions and abscesses are readily seen as low signal on T1-weighted images and high signal areas on STIR images. In order to determine the accuracy of the MRI interpretations, an experienced coloproctologist operated on all 35 patients without the knowledge of the scan interpretations and the findings at surgery were compared with the MRI scan interpretations. Concordance rates between MRI and operative findings were 86% for presence and course of the primary track, 91% for the presence and site of secondary extensions or abscesses and 97% for the presence of horse-shoeing. Although operative findings by an experienced coloproctologist were taken as the gold standard, we have shown that in 9% of our study group, failure of healing was related to pathology missed at surgery which had been documented on pre-operative MRI. It is probable, therefore, that the accuracy of MRI is higher than the figures quoted above. MRI is advocated as the imaging method of choice in the assessment of anal fistulae and its use may lead to a reduction in the recurrence rate due to inaccurate surgical assessment.

Randomized controlled trial of the effect of sulindac on duodenal and rectal polyposis and cell proliferation in patients with familial adenomatous polyposis

Twenty-four patients with familial adenomatous polyposis who had previously undergone prophylactic colectomy and had advanced duodenal polyposis were entered into a randomized trial to assess the effect of the non-steroidal anti-inflammatory drug sulindac on duodenal and rectal polyps. Polyp size and number were assessed by videotaped duodenoscopy (and rectoscopy in 14 patients) at entry and after 6 months of treatment; the tapes were compared by two assessors who were unaware of the randomization and the shuffled chronological order of the recordings. Mucosal cell proliferation was measured by in vitro incorporation of 5-bromo-2'-deoxyuridine. Sulindac therapy was associated with a reduction in epithelial cell proliferation in the duodenum (median labelling index (LI) 15.8 versus 14.4 per cent, P = 0.003) and a trend towards duodenal polyp regression (P = 0.12). In the rectum, cell proliferation showed a marked reduction (median LI 8.5 versus 7.4 per cent, P = 0.018), and significant (P = 0.01) polyp regression was seen. Rectal polyposis was less severe than that in the duodenum and responded more dramatically. Sulindac is a possible treatment for patients in whom rectal polyps have failed to show significant regression after ileorectal anastomosis and who are unsuitable for pouch surgery; it may be useful in early duodenal polyposis or as an adjunct after duodenal clearance.

Life expectancy after colectomy and ileorectal anastomosis for familial adenomatous polyposis

PURPOSE

Despite the introduction of screening, surveillance, and prophylactic colectomy surgery, patients with familial adenomatous polyposis (FAP) are at risk of dying from other malignancies.

METHODS

In order to quantify this risk and identify the causes of mortality, a retrospective life table analysis was performed on 222 patients with familial adenomatous polyposis who had undergone a total colectomy and ileorectal anastomosis between 1948 and 1990. These FAP patients were compared with an age- and sex-matched group of the general population and a relative risk of dying was calculated.

RESULTS

Of 222 patients, 53 have died. In a matched group of the general population the expected number of deaths would be 15.8. The relative risk of dying is therefore 3.35. There has been no significant improvement with time and the relative risk is greatest for female patients.

CONCLUSION

The three main causes of mortality are upper gastrointestinal malignancy, desmoid disease, and perioperative complications. Further research should therefore be aimed at prevention and improved treatment of these in order to improve survival.

An inexpensive method of quality assessment in anastomosis workshops

A method of comparing the quality of intestinal anastomoses performed in craft workshops is described. The equipment is readily available in any hospital, inexpensive and requires no technical construction. The apparatus accurately measures the intraluminal pressure at the first sign of anastomotic leak and a method of deriving the wall tension is explained. Calculation of wall tension at the point of failure allows comparison of anastomoses of different size. An instructor can therefore monitor the improvement of an individual trainee or rank a class according to the quality of their anastomoses.

Iatrogenic pancreatitis in familial adenomatous polyposis

The first case of a patient with familial adenomatous polyposis (FAP) who developed pancreatitis after routine screening and biopsy of the ampulla of Vater is described.

Influence of suture physicochemical and surface topographic structure on tumor cell adherence

Local recurrence following curative resection for colorectal cancer may be caused by the seeding of free malignant cells at the anastomotic site. This study investigated the influence of suture material on in vitro tumor cell adherence. Radiolabeled rat colonic cancer cells (RCC5) were incubated with a variety of suture materials, and the relative contribution of chemical composition and physical configuration to cell adherence was assessed. Nonadherent cells were washed free, and the cell adherence was determined by radioactive counting. Marked differences in adherence were observed, with cells preferentially adhering to protein-based and multifilament sutures. These observations were confirmed using scanning electron microscopy. These findings indicate that both chemical composition and physical configuration influence the adherence of tumor cells to sutures and suggest that the use of protein-based and multifilament sutures be carefully considered in situations where free malignant cells may be present following colorectal surgery.

Solitary juvenile polyps: not a marker for subsequent malignancy

BACKGROUND

Solitary juvenile polyps are considered benign. In contrast, juvenile polyposis is associated with malignancy and poor long-term outcome. Recent reports suggest that solitary juvenile polyps may also undergo both adenomatous and malignant change. The long-term outcome of patients with solitary juvenile polyps is unknown. Patients are treated conservatively and discharged from follow-up. The present study was designed to examine the incidence of cancer and mortality of these patients, comparing their life expectancy with that of the general population.

METHODS

The outcome of 82 patients with a solitary juvenile polyp between 1958 and 1982 was examined by life table analysis. Patients were traced through the Office of Population Censuses and Surveys for death and cancer registration. Patients were compared with an age- and sex-matched group of the general population.

RESULTS

The relative risk of dying for patients who have previously had a solitary juvenile polyp in comparison with the general population was found to be 0.66 (95% confidence interval, 0.34-1.14). There was only one case of colorectal cancer.

CONCLUSIONS

Patients with a solitary juvenile polyp are not at increased risk of dying of or developing colorectal cancer and do not require further follow-up or investigations.

A rapid microplate-based fluorometric assay for phagocytosis

A highly sensitive quantitative fluorometric assay for phagocytosis, previously measured using fluorescence spectrophotometry or flow cytometry, has been adapted for use with a 96-well fluorescence plate reader. The technique allows rapid analysis of large numbers of samples, and requires only a small sample volume. Comparison of plate types demonstrated that opaque white 96-well luminostrips produced a 100 fold greater fluorescent output, and were more sensitive than black fluoroplates. Intraplate variability was also significantly lower using white luminostrips. For the phagocytic assay, fluorescein conjugated polystyrene beads were incubated with macrophage monolayers in white luminostrips. After incubation, cells were washed, lysed and phagocytosis quantified by determining the fluorescent intensity using a fluorescence plate reader. The number of beads phagocytized was determined from a standard curve of bead number versus fluorescent output. The phagocytic activity of resident and thioglycollate-elicited peritoneal macrophages was compared using this technique.

Surgical polypectomy of duodenal adenomas in familial adenomatous polyposis: experience of two European centres

Between 1978 and 1988, 12 patients with familial adenomatous polyposis (FAP) and severe duodenal polyposis underwent duodenotomy and duodenal polypectomy. The patients were from two separate institutions; all were women, with a mean age of 45.6 (range 25-62) years at the time of duodenotomy. Recurrent duodenal polyposis was detected at endoscopy in all 12 patients, at a mean of 13.3 (range 5-36) months after duodenotomy. All patients had moderate to severe duodenal polyposis at the time of the last endoscopic examination. Local excision of duodenal adenomas is an unsatisfactory treatment option in those with FAP. The ideal management of patients with FAP who have severe duodenal polyposis remains uncertain.

Pouch-vaginal fistula

Between January 1976 and June 1991, 161 women underwent restorative proctocolectomy. Seventeen (10.6 per cent) developed pouch-vaginal fistula. There was no difference in the incidence of inflammatory (15 of 141; 10.6 per cent) and non-inflammatory (two of 20; 10 per cent) disease, the severity of colitis or the number of stages in the operation. In 15 patients the fistula involved the ileoanal anastomosis; in two it had possibly occurred at the dentate line. There was no significant difference in the proportion of hand-sewn (ten of 120; 8.3 per cent) and stapled (seven of 41; 17 per cent) ileoanal anastomosis. Of the 17 women, six had pelvic sepsis in the immediate postoperative period and five had an anastomotic complication. There was no case of Crohn's disease. Three patients developed a pouch-vaginal fistula before closure of the ileostomy. The remaining 14 fistulas occurred a median of 7 (range 1-144) months after closure. Five further patients were referred from elsewhere to give a total of 22 for analysis of treatment and outcome. The fistula developed before ileostomy closure in five patients (group 1) and after closure in 17 (group 2). Following treatment, six fistulas had healed with five patients still undergoing treatment. In group 1, three of the five fistulas healed, whereas in group 2 only three of the 17 healed. Eight patients required excision of the pouch. The prognosis appears to be worse when pouch-vaginal fistula occurs after ileostomy closure. The optimal management is not yet established.

Detection and enumeration of circulating tumour cells in colorectal cancer

Immunocytochemistry was used in parallel with conventional cytology to detect circulating malignant epithelial cells in 42 patients undergoing resection for colorectal cancer. Preoperative peripheral and peroperative mesenteric venous blood samples were taken. Tumour cells were isolated on a density gradient and cytospins prepared. Slides were stained by conventional cytology (May-Grünwald-Giemsa) and by an indirect immunoperoxidase technique with the anticytokeratin antibody KG8.13. Using conventional cytology, definite morphological evidence of malignancy was observed in three patients and suspicious features in a further seven. Immunocytochemistry confirmed these findings in all three of the malignant but in only one of the suspicious cases. Counts of immunostained cytospins showed the concentration of tumour cells in blood samples from these four patients to be in the range 0-954 cells/ml. This study supports the use of immunological markers to detect and enumerate malignant cells. This method provides a powerful tool to investigate one aspect of the metastatic process.

DNA adducts, detected by 32P-postlabelling, in DNA treated in vitro with bile from patients with familial adenomatous polyposis and from unaffected controls

Patients with familial adenomatous polyposis (FAP) have a high risk of developing duodenal adenomas and carcinomas. The distribution of these neoplasms resembles mucosal exposure to bile, suggesting that bile may play a role in adenoma development. Our previous results, using DNA adducts detected by 32P-postlabelling as an index of genotoxicity, have supported this hypothesis. We found significantly higher adduct labelling in the duodenum of FAP patients than in the duodenum of control patients and significantly higher labelling in the small bowel of rats gavaged with FAP bile than in rats given control bile. We have now investigated the ability of human bile to form adducts with DNA in vitro. Bile obtained from the gallbladder of 18 FAP patients immediately before colectomy, and from 18 control patients, was incubated with salmon sperm DNA in solution at 37 degrees C for 1 h, after which the purified DNA was analysed for DNA adducts, using the nuclease P1 method of 32P-postlabelling. Relative adduct labelling values (RAL, adducts per 10(9) nucleotides) produced by FAP bile samples were significantly higher than RAL values produced by control bile samples (medians 197 versus 86, P = 0.0016, Mann-Whitney test). We found a consistent pattern of adduct labelling, varying in intensity between samples. Adduct spots were eluted from TLC plates and analyzed by reverse-phase HPLC. Each major spot gave several peaks that were consistent between bile samples from different patients and were similar in FAP and control bile. These results indicate that bile from FAP and control patients contains similar, directly acting genotoxic compounds but that levels are higher in FAP than in control patients. This suggests that bile from FAP patients is more genotoxic than bile from control patients. Incubation of bile with free-radical scavengers and deconjugating enzymes failed to influence adduct labelling in this system.

Total sphincter conservation in high fistula in ano: results of a new approach

An intersphincteric approach has been developed that allows complete sphincter preservation in some patients with high fistulas. This operation in 13 patients (eight trans-sphincteric, five suprasphincteric tracks) has resulted in complete success in seven, partial success (ultimate sacrifice of the internal anal sphincter) in two and failure in four. When the operation is successful continence is better than after failed procedures.

Cellular proliferation at sutured and sutureless colonic anastomoses

Elevated cellular proliferation in the vicinity of an anastomosis may explain the enhanced susceptibility to carcinogens. The aim of this study was to determine whether anastomotic cellular proliferation was altered by different suture materials and whether a rise in cell turnover also occurred after a "sutureless" closure. A transverse descending colon enterotomy was repaired with interrupted sutures of 5/0 silk (n = 20), stainless steel (n = 20), or Vicryl (Ethicon, Inc., Somerville, NJ) (n = 20) or by a sutureless technique (n = 20). Using a stathmokinetic technique, crypt cell production rates (CCPR) were calculated at the anastomosis and in the adjacent colon at varying intervals between one week and six months after treatment. Overall colonic cellular proliferation appeared to be elevated at a sutured colotomy for at least three months (P < 0.05). In contrast, no significant elevation in cellular proliferation was observed at sutureless anastomoses. The duration of elevated proliferative response varied among the sutures.

Repair of rectocoele using Marlex mesh

A new operation for rectocoele which places Marlex mesh in the rectovaginal septum is described in four women, of whom three have normal defaecation and one is improved but still needs occasionally to use digital perineal pressure. The aetiology of rectocoele is discussed.

Suppression of macrophage function by suture materials and anastomotic recurrence of Crohn's disease

After surgical excision of bowel, Crohn's disease is likely to recur around the anastomosis. It is suggested that this may indicate a biological effect of suture materials on gastrointestinal immunology. To investigate this, the influence of six suture materials on the function of macrophages obtained from the rat peritoneal cavity and human intestinal mucosa was assessed. All materials significantly impaired macrophage function.

Colectomy with ileorectal anastomosis lowers rectal mucosal cell proliferation in familial adenomatous polyposis

Rectal polyp regression has been observed in familial adenomatous polyposis (FAP) after colectomy and ileorectal anastomosis (IRA). In view of the association between risk of neoplasia and epithelial cell turnover rates, a study was conducted to determine the effect of colectomy and IRA on rectal mucosal proliferation in FAP. Endoscopic biopsies of flat rectal mucosa were taken from 12 FAP patients with an established IRA and 10 FAP patients prior to colectomy. Mucosal proliferation was assessed by flash-labeling S-phase cells with bromodeoxyuridine. Labeled cells were visualized on paraffin sections with an immunohistochemical stain using a monoclonal antibody to bromodeoxyuridine. Twenty crypt columns were analyzed. The mean labeling index (percent labeled cells/crypt) of the FAP patients with established IRAs (7.0 +/- 1.4 percent) was significantly less than that of the precolectomy patients (12.8 +/- 3.0 percent) (Mann-Whitney U test, P = 0.0004). Comparison of labeled distribution curves shows a contraction of the crypt proliferative zone in the IRA group. Colectomy with IRA in FAP is associated with a significant reduction in rectal mucosal cell proliferation. These findings support the claim of reduced risk of rectal cancer following this procedure in FAP and are of relevance to the study of environmental vs. genetic control of cell proliferation.

[Initial experience with the AKA-2 and AKA-4 device for intestinal compression anastomosis in colorectal surgery]

A prospective study was undertaken to analyse the results of sutureless colorectal anastomosis, by using an anastomotic compression device designed by Russians, the AKA gun. Ten patients were submitted do colorectal resection, 5 for retrosigmoid cancer, 3 for familial adenomatous polyposis and 2 for rectal procidentia. No mortality. Anastomotic leakage occurred in 1 patient which was treated by a defunctioning colostomy and had a good recovery. Clinical, radiologic and endoscopic postoperative controls were within normality. Comparisons are made between the sutureless anastomosis technique and the traditional ones. Initial results are regarded, by the authors, as encouraging and so they intend to go on the study.

Rectal cancer risk in older patients with familial adenomatous polyposis and an ileorectal anastomosis: a cause for concern

The risk of rectal cancer in 224 patients with familial adenomatous polyposis with an ileorectal anastomosis has been estimated by life-table analysis. Until the age of 50 years the cumulative risk is reasonably low at 10 per cent (95 per cent confidence interval 4.5-16 per cent), increasing sharply to 29 per cent (95 per cent confidence interval 18-40 per cent) by the age of 60 years. This means that surveillance of the retained rectum in older patients must either be improved or they should undergo restorative proctocolectomy in earlier middle age.

Experimental carcinogenesis at sutured and sutureless colonic anastomoses

This study explores the role of sutures and the healing colonic wound in experimental carcinogenesis. One hundred sixty rats underwent surgery with colotomy and repair using silk, steel, or Vicryl (Ethicon, Somerville, NJ) sutures or a sutureless technique. Forty rats had a sham procedure. All animals received azoxymethane for 12 weeks at a dose of 10 mg/kg/week. Half the rats commenced carcinogen before surgery, and half commenced it eight weeks after surgery. Animals with anastomotic tumors were found in 46 percent of the sham group (P less than 0.05 cf. sutured), 41 percent of the sutureless group (P less than 0.02 cf. sutured), and 68 percent of the sutured group. The corresponding figures for anastomotic carcinoma were 9 percent (P less than 0.001 cf. sutured), 22 percent, and 38 percent. No significant differences in tumor yield were noted among the different sutures. However, several differences were noted between the two carcinogen models. In those animals that received surgery first, there was a higher incidence of anastomotic tumors (P less than 0.002) and cancers (P less than 0.0001) in the sutured and sutureless groups, and those tumors that occurred in the sutured group were considerably larger than in those that had carcinogen first (15.9 mm cf. 4.9 mm; P less than 0.0001). Overall, all sutures seem to enhance anastomotic tumor formation, and we would suggest that a sutureless anastomosis may diminish this risk.

Anatomy and function of the anal longitudinal muscle

The longitudinal muscle in the intersphincteric space has received little attention despite an explosion of interest in anorectal physiology in the past decade. Its anatomy is contested and its function unknown. Speculation, however, gives it a role as a skeleton supporting and binding the rest of the internal and external sphincter complex together, as an aid during defaecation by everting the anus, as a support to the haemorrhoidal cushions, and as a determining factor in the ramification of sepsis.

Magnetic resonance imaging of anal fistulae

Success of surgery for an anal fistula depends on accurate assessment of the fistula; however, such assessment is technically difficult. We have done a prospective study that determined the accuracy of magnetic resonance imaging (MRI) in demonstrating the course of fistulae, by comparing MRI scan interpretations with subsequent operative findings. 16 patients (mean [range] age 42 [24-66] years) had MRI followed by surgery within a mean of 22 (1-101) days. MRI scan interpretations agreed precisely with independently documented operative findings in 14 of 16 patients. MRI is an accurate method of delineating anal fistulae, and should be considered for patients with difficult fistulae that recur despite skilled attention because it demonstrates abnormalities that might otherwise be missed.

Duplex Doppler ultrasound identifies veins suitable for insertion of central feeding catheters

Central venous access for feeding catheters may prove difficult in patients who have had numerous previous central line insertions or complications. Duplex Doppler ultrasound was used to identify the anatomy and patency of major central veins in 11 patients in whom attempts at obtaining central venous access by an experienced operator had failed at least once and in 40 control subjects. Doppler ultrasound demonstrated the subclavian veins (diameter 12.5 +/- 3.5 mm, mean +/- SE) and internal jugular veins (11 +/- 3.5 mm) in all the control subjects. In the patients, 18 of 44 veins were patent, 11 were small or had low blood flow, and 15 were thrombosed. In 7 patients who required central feeding catheter insertion, a suitable vein was identified and the catheter suitably placed, even in 3 subjects where no central vein was considered normal. Duplex Doppler ultrasonography is a useful technique for identifying veins suitable for the insertion of central venous lines when access has previously proved difficult.

Adequate distal margin of resection for adenocarcinoma of the rectum

There are two questions in the surgical treatment of rectal cancer: (1) How far below a palpable rectal cancer should a surgeon cut in order to avoid cutting through cancer and, (2) Given that the surgeon has not cut through cancer, could the chance of subsequent recurrent rectal cancer have been reduced if an even greater length of bowel had been removed. For mobile tumors that are not poorly differentiated the answer to the first question is far enough in order to get a right-angled clamp on below the tumor that will not slip; the answer to the second question is no.

DNA adducts detected by 32P-postlabelling, in the intestine of rats given bile from patients with familial adenomatous polyposis and from unaffected controls

Duodenal adenomas are common in patients with familial adenomatous polyposis (FAP) and cluster around the papilla, suggesting the involvement of bile in their development. Using 32P-postlabelling we determined levels of DNA adducts in the small bowel and colon of rats treated with bile from FAP and control patients. We found a significantly higher level of adducts in the small bowel of rats treated with FAP gallbladder bile compared with control gallbladder bile (P = 0.0034). This result supports the hypothesis that bile plays a role in the development of neoplasia in the foregut of FAP patients.

Partial colectomy and coloanal anastomosis for idiopathic megarectum and megacolon

Adult patients with an idiopathic megarectum or megacolon can experience severe constipation requiring surgical treatment. Some of these patients have a proximal colon of normal diameter, with dilatation involving only the left or distal colon and rectum. The results of partial colonic and rectal resection with coloanal anastomosis in such patients have been reviewed. Seven patients (two female and five male) underwent a coloanal anastomosis over a seven-year period. The median age at operation was 19 years, the mean age at onset of symptoms was five years, and the mean follow-up period was one year. Five patients experienced a return to normal bowel frequency with the loss of most symptoms. One patient has an ileostomy because of persistent constipation after the procedure. One subject died because of postoperative bleeding from the anastomosis and subsequent cardiac and respiratory complications. This operation may have a place in the treatment of severe constipation caused by idiopathic megarectum and megacolon, but careful preoperative motility studies and meticulous attention to operative technique are required for a good outcome.

Rectal Polyposis as a Guide to Duodenal Polyposis in Familial Adenomatous Polyposis

Almost all patients with familial adenomatous polyposis (FAP) develop duodenal polyps, the severity of which is graded stage 1 (minor) to stage V (cancer). Regular endoscopy is recommended for all patients with FAP. To test whether the development of severe duodenal polyposis could be predicted in another way, rectal and duodenal polyp severity were compared in 91 patients with FAP. The fulguration ratio (number of rectal fulgurations divided by number of years since colectomy) supplied the rectal polyp severity index. Patients with stage V duodenal polyposis had significantly higher fulguration ratios (median 0.38) than did patients with stage 1 disease (median 0; P=0.009). However, the wide scatter of results means that rectal polyp severity cannot be used as a guide to duodenal polyp severity in individual patients. The coexistence of populations with severe duodenal and rectal polyposis suggests that environmental factors are important in phenotypic expression in FAP.

Bacteriology of anal fistulae

Anal fistulae are said to arise from cryptoglandular infection of the anal glands, which lie within the intersphincteric space. The type and virulence of the micro-organism responsible may determine whether an anal fistula develops. The microbiology of chronic anal fistulae has not been reported previously. Twenty-five consecutive anal fistulae were studied prospectively (eight intersphincteric fistulae, 12 trans-sphincteric fistulae, two suprasphincteric fistulae, one extrasphincteric fistula, one superficial fistula, one anovaginal fistula). There were 18 men and seven women, with a median age of 42 (range 22-71) years. Patients with Crohn's disease or acute anorectal suppuration were excluded. In 18 patients, 0.1 ml granulation tissue from the track of the fistula was obtained and processed within 4 h using standard microbiological techniques. Sixty-nine isolates representing at least 17 species were obtained. The predominant organisms were Escherichia coli (22 per cent), Enterococcus spp. (16 per cent) and Bacteroides fragilis (20 per cent). The majority of the growths were obtained only from enrichment. Bacteria from only one patient grew at a dilution of 10(3). Granulation tissue from 25 patients was processed for mycobacterial culture, and Mycobacterium tuberculosis was grown from one patient. No other mycobacterium was isolated. The chronic inflammation in anal fistulae does not seem to be maintained by either excessive numbers of organisms or organisms of an unusual type.

Sutureless intestinal anastomoses

Sutureless intestinal anastomoses can be achieved either by compression, where two inverted rings of bowel are compressed by a hollow circular device that subsequently sloughs away and is passed anally, or by the use of tissue glues or laser welding. Compression devices used clinically with success are the Valtrac biofragmentable anastomotic ring, the polypropylene rings described by Rosati and the AKA guns. Glued anastomoses have only been used in animals and seem to be unsafe. However, laser-welded intestinal anastomoses appear highly promising in experimental studies and further development of this technique is warranted.