Urolithiasis risk factors in continent reservoir ileostomy patients

Conventional ileostomy patients are at an increased risk to urinary stone formation compared to normal controls. This study was designed to evaluate any further risk factors to urinary stone formation in patients with Kock ileostomies. Nine Kock ileostomy patients were matched for age, sex, and body weight with nine conventional ileostomy patients and nine controls. Two 24-hour urine samples from each patient were analyzed for volume, pH, Na⁺/K⁺ ratio, oxalate, and uric acid concentration. Both ileostomy groups demonstrated reduced urinary volume and Na⁺/K⁺ ratio as compared to the control groups (P<0.05). The Kock ileostomy group had the lowest urinary volume. There was no significant reduction in urinary pH or elevation in urine uric acid concentration in the Kock ileostomy group. The results suggest that there is no significantly added risk to uric acid stone formation in Kock ileostomy patients     

Volume capacity and pressure characteristics of the continent ileostomy reservoir

The volume capacity and the pressure characteristics of the ileal reservoir were studied at intervals postoperatively in 28 patients with continent ileostomy. The reservoir volume increased during the first 6 months from 100 ml to approximately 700 ml, after which it remained stable. The basal pressure increased during filling to a maximum of roughly 10 cm H2O. Under 'physiological conditions' the basal pressure was around 4 cm H2O before emptying. Two types of pressure waves occurred, small pressure fluctuations with a frequency of 7-8/min and larger phasic waves appearing when approximately 40% of the reservoir volume capacity had been reached. The occurrence of both types of pressure waves decreased with time. The total motor activity, expressed as the area underneath the pressure waves, decreased considerably during the 1st year after operation, indicating an adaptation of the intestinal smooth muscle to distension. The results confirm the original concept proposed by Kock that the ileal reservoir constructed in this manner is a low-pressure reservoir.     

Multiple adenomatous polyps arising in a continent reservoir ileostomy

In a 29-year-old man who presented with leakage from a continent ileostomy after proctocolectomy, endoscopic evaluation of the reservoir revealed extensive adenomatous polyposis. The polyps were not present at the time of revision of the reservoir 4 years earlier. Because it was not possible to fashion an adequate nipple valve in the presence of so many polyps and the concern over possible malignant transformation, the reservoir was excised. This is the second reported case of polyposis involving a continent reservoir ileostomy. Patients with a continent ileostomy constructed after proctocolectomy for polyposis coli should be evaluated endoscopically at regular intervals.     

Mucosal alterations in the reservoir of patients with Kock's continent ileostomy

Mucosal alterations in the reservoir of 10 patients with Kock's continent ileostomy were investigated and compared with normal ileal mucosa. Morphometric measurements showed a decreased villus length and an increased crypt length as compared with the control group. When the villus to crypt ratio was related to the time elapsed after the continent ileostomy operation, a decrease could be found. Light microscopy evaluations showed colon-like characteristics, which was confirmed by the detection of goblet-cell hyperplasia and the occurrence of sulphomucin-producing cells in the reservoir's mucosa. The number and type of neuroendocrine cells, however, remained unaltered. Dysplastic changes did not occur.     

Evolution of continent ileostomy

Continent ileostomy can be defined as a surgical procedure that facilitates planned intermittent evacuation of a bowel reservoir through an ileostomy. It was devised by Nils Kock in 1969. Subsequently, continent ileostomy (or Kock pouch) became a viable alternative in the management of patients who had traditionally required an end ileostomy. Kock pouch appeared to provide substantial physical and psychosocial benefits over a conventional ileostomy. The procedure became popular until ileal pouch anal anastomosis (IPAA) was introduced in 1980. Despite its benefits, continent ileostomy had many short term complications including intubation problems, ileus, anastomotic leaks, peritonitis and valve problems. Operative mortalities have also been reported in the literature. Most of these problems have been eliminated with increasing experience; however, valve-related problems remain as an "Achilles' heel" of the technique. Many modifications have been introduced to prevent this problem. Some patients have had their pouch removed because of complications mainly related to valve dysfunction. Although revision rates can be high, most of the patients who retain their reservoirs are satisfied with regard to their health status and quality of life. Today, this procedure is still appropriate for selected patients for whom pouch surgery is not possible or for patients who have failed IPAA. Both the patient and their physician must be highly motivated to accept the risk of failure and the subsequent need for revisional operations.     

Fistula following continent ileostomy

A patient who developed a fistula secondary to Marlex mesh in the nipple valve of a continent ileostomy is reported. Etiology and management of fistula following continent ileostomy are discussed. Fistula formation should be recognized as a potential hazard of the use of prosthetic material to stabilize the nipple valve of a continent ileostomy.     

Facts about the kock continent ileostomy

A great number of publications on the results obtained by different techniques employed for construction of the continent ileostomy have been published over the years. Unfortunately, many reports are incomplete or presented in such a way that they do not allow for proper interpretation or mutual comparison. Analysis of the collective results obtained from studies where the different techniques employed are accurately described and complications properly specified demonstrates more clearly what measures may improve the success rate and which factors have to be taken into account for anyone who is going to adopt the method. Maintaining a continuing flow of appropriate material for this section is impossible, at least currently. Nevertheless, from time to time, we do receive unsolicited review articles that furnish concise, up-to-date information on specific subjects, and they will appear in this section. Subjects covered, obviously, will depend upon our contributors.     

Long-term results of continent ileostomy

The long-term results of 76 Kock continent ileostomy operations were evaluated at an average 9 years postoperatively. The early complication rate was 36%: 11 (14%) patients underwent reoperation including one (1.3%) pouch removal, and one patient died. Late complications occurred in 54 (73%) patients. These included two (2.7%) pouch-related deaths, 30 (41%) cases of nipple-valve sliding, 22 (30%) clinically observed cases of pouchitis, 12 (16%) patients with stomal strictures, and intestinal obstruction (7), ventral hernia (4), nipple-valve fistula (7), intra-abdominal abscess (4) and foreign body in the reservoir (7). Revisional surgery was required in 49 (66%) patients. Despite this high cumulative complication rate a good functional result was ultimately attained in 62 (83%) patients. Only four reservoirs were removed, and only three patients had to wear an appliance. Increasing experience with the method resulted in a marked decrease of both early and late complications. The high degree of patient satisfaction supports continuation of Kock ileostomy constructions even though prolonged follow-up and frequent reoperations may be required.     

Stagnant loop syndrome in patients with continent ileostomy (intra-abdominal ileal reservoir).

Intestinal absorption and bacteriology of the ileal contents were compared in seven patients with continent ileostomy and seven patients with conventional ileostomy. The absorption of vitamin B12 was reduced in five patients with continent ileostomy and subnormal in two patients with conventional ileostomy. Steatorrhoea was present in four patients with continent and one patient with conventional ileostomy. Increased concentrations of total anaerobic bacteria and Bacteroides were found in the ileum of the patients with continent ileostomy. After an oral dose of (1-14C) glycocholic acid there was no difference in the faecal excretion of radioactivity, whereas the 14CO2-expiration was increased in two patients with continent ileostomy. In four patients with continent ileostomy and malabsorption of B12, there was evidence of a stagnant loopsyndrome as oral lincomycin treatment resulted in increased absorption of B12 decreased excretion of faecal fat, and decreased concentrations of Bacteroides in the ileum.     

Diarrhoea after continent ileostomy.

To determine the nature and frequency of malabsorption in patients with continent ileostomies, faeces and urine from 42 patients with ileal pouches and from 19 patients with conventional ileostomies were analysed and compared. The patients with conventional ileostomy were matched with patients with ileal pouches. Thirteen of the patients with pouches were found to have excessive faecal volumes which were accompanied by increased faecal losses of electrolytes, nitrogen, and fat, and by decreased vitamin B12 uptake. The remaining patients with continent ileostomies had faecal and urinary outputs which were similar to those of patients with conventional ileostomies. Thus, evidence of malabsorption was found in approximately 30% of this group of patients with continent ileostomies.     

Technique for revision of continent ileostomy

A technique is described for revising an incompetent nipple valve of a continent ileostomy. The procedure involves preserving the incompetent valve and using it as a collar around the base of the new valve to improve function.     

A new type of continent ileostomy

Kock's continent ileostomy is a well-established technique, however, it is technically difficult to construct and has a high incidence of complications. This study evaluates a new type of mucosal valve constructed in continuity with an intestinal reservoir. The valve is created along the antimesenteric border of the efferent limb 0.5 cm distal to the reservoir. The seromuscular layer is “stripped” from the mucosal layer for 50 per cent of the bowel circumference and then excised. The remaining seromuscular borders are then sutured to the apex of the pouch and along the antimesenteric border of the afferent limb. In this way the valve is created and, upon distention of the afferent limb and apex of the pouch, the valve closes. In seven dogs such a continent ileostomy was constructed and all were clinically continent. The reservoirs were intubated through the ileostomy two to three times a day. The mean volume aspirated was 143 ml/day. After eight weeks, radiographic and volume-pressure studies were performed. Prior to sacrifice, increasing volumes of barium were instilled into each pouch via the afferent limb and radiographs were taken: these studies confirmed the continence in all seven ileostomies. Following this the reservoirs were intubated and the instilled barium was aspirated. Then Ringer's solution was instilled into each pouch with continuous intrapouch pressure measurements. The pressure remained at 0 cm H₂O until a mean volume of 243 ml was exceeded. The mean volume at which incontinence occurred was 415 ml.     

Faecal excretion of intravenously injected 14C-cholic acid in patients with conventional ileostomy and in patients with continent ileostomy reservoir.

Bile salt absorption, as determined by the faecal excretion in i.v. injected 14C-cholic acid (FBS) was studied in 13 ileostomy patients before and after conversion to Kock's continent ileostomy reservoir. The result was compared with that obtained in 8 ileostomy patients in whom about 50 cm of the terminal ileum has also been removed. As compared with 16 healthy controls, FBS was moderately increased in the conventional ileostomy patients, but still within normal limits. After conversion to ileostomy reservoir all patients had pathological FBS, although less severe than in the ileostomy patients with ileal resection. Bacterial contamination probably contributes more than the structural mucosal changes to the bile malabsorption in the pouch, whereas reduced mucosal surface and short small-intestinal transit time are the main causes of malabsorption in ileostomy patients in whom an appreciable amount of the terminal ileum has been resected.