Search PubMed⌕ Search

Biomedical subjects

N G Kock

Publications and source records attributed to N G Kock.

At least 19 recordsLinked to original sources
PubMed1992

Ileostomy output of gas and feces before and after conversion from conventional to reservoir ileostomy.

In 28 patients who had previously had a proctocolectomy for ulcerative colitis, the ileostomy output of feces was determined before and after conversion to continent reservoir ileostomy, as was the output of gas in 20 of the patients. The median output of feces/24 hours collected in the hospital was 576 g before and 692 g after conversion (P less than 0.05); when collected at home the corresponding figures were 734 g and 740 g, respectively. In the majority of patients, the change in fecal ileostomy output after the conversion was not considerable, while in a few patients there was a marked increase. The fecal output was 24 percent (P less than 0.01) and 11 percent (P less than 0.01) larger at home than in hospital before and after conversion, respectively. The proportion dry weight of ileostomy discharge decreased after conversion (P less than 0.01). The median gas volume in the ileostomy output/24 hours was 1,664 ml before and 1,450 ml after conversion. The gas constituted 58 percent of the output and is significant with respect to the required reservoir capacity. Recording the emptying volumes and frequency in patients with reservoir ileostomy showed that, in general, patients with large output expand their reservoir capacity instead of increasing their emptying frequency.

Adult↗
PubMed1992

Further experience with the urethral Kock pouch.

In 185 men a urethral Kock pouch was constructed as a bladder substitute after radical cystectomy for cancer. A total of 117 patients was followed for a minimum of 1 year and is fully evaluable. Of the patients 108 (92%) are completely continent during the day, while 85 (73%) are dry at night. Also, 8 patients had an excellent response to imipramine hydrochloride. Stability or improvement in the configuration of the upper tract was noted in 210 renal units (90%). A total of 24 renal units showed evidence of deterioration due to reflux (16) and an anastomotic stricture (8). Stability of the antireflux nipple valve was ensured by creation of a window in the mesentery of the corresponding bowel segment and by anchoring the valve to the wall of the pouch by an additional row of staples. On the basis of this favorable outcome the procedure is recommended for male patients for whom cystectomy is indicated and in whom the urethra can be preserved.

Cystectomy↗
PubMed1992

Further experience with the modified rectal bladder (the augmented and valved rectum) for urine diversion.

Continent diversion with the modified rectal bladder was done in 83 patients and 65 are currently evaluable with followup ranging from 6 to 36 months. There was no postoperative mortality and the morbidity rate was acceptable. Renal function and configuration were maintained in most patients (91%). Dessusception of the colorectal valve was observed in 7.6% of the patients. Evidence was provided that this valve is effective in prevention of regurgitation of the rectal contents to the proximal colon. All patients were continent during the day. Enuresis was noted in 6 patients and all of them responded to imipramine hydrochloride therapy. The results support earlier observations that the procedure offers distinct advantages over ureterosigmoidostomy and the simple rectal bladder.

Adult↗
PubMed1992

Significance of the antireflux valve for upper urinary tract pressure. An experimental study in patients with urinary diversion via a continent ileal reservoir.

When bladder substitution is required, a low pressure receptacle and an antireflux valve with low resistance to flow is essential for preservation of the upper urinary tract. The aim of this study was to evaluate whether these criteria are attained in the continent ileal reservoir used for urinary diversion. The investigations were performed in six patients more than one year after supravesical urinary diversion via a continent ileal reservoir. The pressure was recorded simultaneously both in the afferent loop and in the reservoir during filling of the reservoir. There was a slow parallel increase in the basal pressure in the reservoir and the afferent loop. Pressure waves appeared sometimes simultaneously and sometimes in only one compartment at a time. Only during short periods of time did the pressure exceed 25 cm of water. The frequency of pressure waves increased with increased filling of the reservoir. The "total pressure" was larger in the reservoir than in the afferent loop. It is the antireflux valve which prevents pressure rises in the reservoir from being conveyed to the upper urinary tract. The resistance to urinary flow was moderate.

Humans↗
PubMed1992

[Evolution of urinary bladder substitution].

The historical background to the currently used methods for continent bladder substitution is shortly outlined. The significance for the patient's quality of life of various methods for bladder reconstruction or urinary diversion is briefly discussed. The importance of reservoir configuration for achieving a high compliant urinary receptacle is pointed out. Factors affecting reabsorption of urinary constituents are stressed and the significance of an antireflux mechanism is discussed. Currently the majority of patients undergoing cystectomy for cancer or for other reasons can be offered bladder substitutes providing continence and easy emptying; that is, complete control over voiding. This can be achieved by orthotopic bladder reconstruction or by diverting the urine to the augmented and valved rectum or to the skin via a continent intestinal reservoir.

Cystectomy↗
PubMed1991

Decreased absorption of 22Na and 36Cl in ileal reservoirs after exposure to urine. An experimental study in patients with continent ileal reservoirs for urinary or fecal diversion.

After urinary diversion to intestinal segments, reabsorption of chloride, ammonium, and hydrogen ions occurs, sometimes leading to hyperchloremic acidosis. The mucosa of ileal reservoirs exposed to urine show substantial atrophy, indicating a loss of absorptive capacity. In ten patients with urinary diversion via a continent ileal reservoir, the absorption of [22Na] and [36Cl] was studied after instillation for 15 min into the reservoir of a test solution containing 50 kBq [22Na] and 50 kBq [36Cl]. The activity of the radionuclides was determined in serum samples after 60 and 180 min and the fractions absorbed were calculated. Absorption of the two radionuclides was also calculated by comparison of the activities in samples of the test solution taken before and 15 min after instillation into the reservoir. The same investigations were performed in seven patients with continent ileostomy reservoirs. The study demonstrated a decreased capacity to absorb [22Na] and [36Cl] across the mucosa of the reservoirs exposed to urine compared to the mucosa of those exposed to feces. Due to the transformation of the ileal mucosa after exposure to urine, the risk for development of metabolic disturbances should be minimal after urinary diversion to a continent ileal reservoir.

Chlorine↗
PubMed1991

Bladder substitutes controlled by the anal sphincter: a comparison of the different absorption potentials.

A comparative study of the absorption potentials of the simple rectal bladder (10 patients), modified rectal bladder (20) and ureterosigmoidostomy (10) was done with intrarectal instillation of 22sodium. Results indicate that absorption is significantly greater among patients with ureterosigmoidostomy. The emptying patterns of ureterosigmoidostomy and the modified rectal bladder were also studied by ascending scintigraphy with 99mtechnetium. Evidence was provided that in cases with ureterosigmoidostomy the isotope is distributed throughout the entire colon. These studies proved the role of the colorectal valve in preventing reflux of urine from the rectum to the proximal colon. Consequently, the surface area of colonic mucosa exposed to urine is decreased and the rate of reabsorption is limited.

Absorption↗
PubMed1991

Pregnancy and delivery in patients with urinary diversion through the continent ileal reservoir.

The social and psychologic sequelae after external urinary diversion are known to be fewer in patients with urinary diversion through the continent ileal reservoir (Kock pouch) compared with those with diversion through the incontinent ileal conduit. Therefore, in young female patients treated surgically with urinary diversion through the continent ileal reservoir, a number of pregnancies can be expected. We report herein the results of four pregnancies in three women with this type of reservoir. All deliveries were vaginal. One patient showed urinary obstruction at the end of the pregnancy and delivery was induced. This particular infant was treated with phototherapy because of hyperbilirubinemia; the other three infants were mature. No damage to renal function was noted and revisional surgical treatment of the reservoir was not necessary in any. Consequently, pregnancy is not contraindicated after urinary diversion through the continent ileal reservoir (Koch pouch).

Adult↗
PubMed1990

Long-term follow-up of patients with continent ileostomies.

Thirty-six patients were evaluated after having continent ileostomies for 16 to 20 years. Follow-up included clinical examination, response to a questionnaire, blood tests, and radiologic studies of the gallbladder. In addition, reservoir biopsies from 15 patients were examined. The patients were in excellent general health, all but one having gained weight postoperatively. There was no increased risk for gallstone formation or for urinary tract stone development. Although 11 of the 36 patients had reservoirs that were not provided with a valve, 92 percent of all patients were continent. Working capacity was normal in most patients and no harmful effects of the reservoir were revealed by morphologic or biochemical studies. In conclusion, no deleterious long-term effects were found as a result of the continent ileostomy.

Activities of Daily Living↗
PubMed1989

Ileoanal anastomosis with interposition of the ileal 'Kock pouch'. Preliminary results.

For patients needing proctocolectomy, there are several alternatives available today for the previously dominating conventional ileostomy. Currently, the ileal pouch-anal anastomosis attracts major interest. Various reservoir procedures have been proposed, but the ideal reservoir design is still debated. The double-folded ileal reservoir (Kock pouch) has a large capacity, low pressure, and is expandable. It is successfully used for the construction of continent ileostomies, continent urostomies, and for replacing the urinary bladder by connecting the reservoir to the urethra. In view of these facts, it was decided to interpose the Kock pouch between the ileum and the anus after colectomy and mucosal proctectomy in a small number of patients, and to study and evaluate its merits in this position. Six consecutive patients formed the study group. Three months after ileostomy closure the stool frequency was 4 every 24-hours, range 3 to 5, and remained so during the follow-up period. All patients could sleep through the night without bowel movements or soiling. None of the patients used pads. The capacity of the reservoir increased from a mean of 100 ml preoperatively to 550 ml one year after ileostomy closure. The large reservoir capacity and the low pressure can explain the good functional results.

Adolescent↗
PubMed1989

Renal function and upper urinary tract configuration following urinary diversion to a continent ileal reservoir (Kock pouch): a prospective 5 to 11-year followup after reservoir construction.

We followed 17 patients who underwent urinary diversion via a continent ileal reservoir (Kock pouch) with yearly examinations for 5 to 11 years postoperatively. The examinations involved control of renal function and configuration of the upper urinary tract. In 5 patients the upper urinary tract had become dilated during followup and in 2 of these renal scarring also had developed. All 5 patients had endured temporary outflow obstruction or reflux (stricture, overdistension of the reservoir or a defective antireflux valve). Of the patients 1 had a marked decrease in renal function before the outflow obstruction was corrected by an operation. Routine blood chemistry study was normal and hyperchloremic acidosis was not noted in any patient. After peroral loading of 6 patients with ammonium chloride significant excretion of titratable acid was found in the urine. Substitution with vitamin B12 was given to 6 patients due to subnormal values in 2 and borderline values in 4.

Follow-Up Studies↗
PubMed1989

Replacement of the bladder by the urethral Kock pouch: functional results, urodynamics and radiological features.

After cystoprostatectomy for cancer of the bladder 43 men were provided with a detubularized, low pressure ileal reservoir (Kock pouch) connected to the urethra. Reflux was prevented by an intussusception valve. There was no operative mortality and few early complications. At followup the mean postoperative observation time was 13 months, with a range of 5 to 20 months. Late complications included manifestations of local tumor recurrence or distant metastases in 9 patients within 6 months postoperatively, which made adequate functional evaluation impossible. In 18 patients reflux to the upper urinary tract due to eversion or sliding of the antireflux valve occurred at various postoperative intervals. In 16 of these patients incontinence developed as a consequence of the reflux. Surgical correction of the failing antireflux valve restored reflux prevention and continence. Within 3 to 6 months the capacity of the reservoirs had reached an ultimate volume of approximately 600 ml. Pressure waves exceeding 40 cm. water seldom occurred in the mature reservoirs and then only at high filling volumes. The mean urethral resting resistance to flow was 64 cm. water. The configuration and function of the upper urinary tract improved or stabilized postoperatively. Of 34 evaluable patients 30 were continent during the day with a voiding frequency of 3 to 5 times and dry at night with a frequency of 0 to 2.

Adult↗
PubMed1989

Voiding pattern, urinary volume, composition and bacterial contamination in patients with urinary diversion via a continent ileal reservoir.

A series of 41 patients with a continent ileal reservoir for urinary diversion (Kock pouch) was studied with regard to voiding pattern (voiding frequency), voided volume, urinary composition, bacterial contamination and mucus secretion. The mean voiding frequency in 21 patients was 5/24 h and the time required for the procedure, including the time to cover the stoma with a bandage, was 3 to 5 min; 2 patients voided once or twice at night, while 19 patients never did so. The mean volume voided during the day were significantly smaller than the volume voided in the morning. The total 24-h urinary volume exceeded that of normal individuals but the 24-h secretion of electrolytes was within normal limits. Bacterial contamination was found in most samples of urine. Evacuation was not impeded by the rich mucus content of the urine and mucus production did not diminish with time.

Adult↗
PubMed1988

Absorption of L-phenylalanine in human ileal reservoirs exposed to urine.

The mucosa of ileal reservoirs exposed to urine undergoes successive structural changes, indicating a loss of absorptive capacity. In patients with urinary diversion via a continent ileal reservoir, the active absorption of L-phenylalanine from the reservoir was studied at different postoperative time intervals. A test solution containing L-phenylalanine was instilled into the reservoir and samples were taken at intervals during a period of one hour for determination of phenylalanine. In one group of patients, urine from the kidneys by-passed the reservoir via a catheter inserted into the afferent segment. Within three months after construction of the ileal reservoir, the uptake was significantly slower than that in ileostomy reservoirs and the absorption decreased even more with longer observation times. Mixing of urine with the reservoir contents did not influence the uptake of L-phenylalanine to any significant degree. The reduced absorption of L-phenylalanine indicates that the uptake of other substances from this type of ileal reservoirs might be decreased also.

Absorption↗
PubMed1988

Quality of life in ileostomy patients before and after conversion to the continent ileostomy.

In a prospective study the quality of life was evaluated in 31 consecutive patients before and after conversion from a conventional to a continent ileostomy. Patient expectations, immediate emotional reactions after the operation and attitudes at the time of the interview were more positive towards the continent ileostomy than the conventional ileostomy. An improved working capacity was affirmed after conversion to the continent ileostomy. Leisure activities and the quality of sexual life were most positively influenced by the continent ileostomy, whereas established family and social relations were not considerably influenced by either type of ileostomy. In conclusion the continent ileostomy improves the quality of life in patients requesting conversion from a conventional ileostomy.

Adaptation, Psychological↗
PubMed1988

Urinary diversion to the augmented and valved rectum: preliminary results with a novel surgical procedure.

A new method for urinary diversion to the rectum was elaborated in animal experiments and currently has been used in 19 patients. Reflux of the rectal content to the colon and to the upper urinary tract is prevented by the fashioning of an intussusception valve at the rectosigmoid junction. The rectum is augmented by anastomosing an ileal patch to the anterior rectal wall. A transverse colostomy protects the construction for 6 to 8 weeks. Of the 19 patients 3 had local recurrence or metastasis within 6 months. Thus, 16 patients with a followup of 3 to 14 months are evaluable. All patients are continent during the daytime with an emptying frequency of 3 to 5 times and dry at night with a frequency of 0 to 2. In 3 patients partial sliding of the sigmoid intussusception valve occurred causing reflux of rectal contents to the sigmoid and to the right ureter in 1. Reflux to the upper urinary tract has not been revealed in any of the other patients. With 1 exception excretory urography has demonstrated either improvement or stabilization of the upper urinary tract post-operatively. The rectal capacity increased from 200 to 700 ml. after 6 months. With the reservoir full the mean basal pressure was 17 cm. water and the mean maximum pressure was 24 cm. water.

Adult↗
PubMed1988

Urinary diversion to the augmented and valved rectum. An experimental study in dogs.

A new model for diverting urine to the rectum was tried in dogs. An intussusception valve was constructed at the junction of the sigmoid colon and the rectum allowing passage only in aboral direction. The rectum was augmented by patching it with an opened and folded ileal segment. The ureters were implanted into the rectum by a new anti-reflux method. All three dogs survived the operation. The volume of the augmented rectum increased from 80-150 ml at operation to a maximum of 750 ml six months after the operation. The pressure in the rectum did not exceed 18 cm of water during maximal filling. No reflux to the bowel proximal to the intussusception valve or to the ureters could be observed even during maximal filling of the augmented rectum. No signs of obstruction of the fecal stream by the intussusception valve were seen. In three out of five implanted renal units strictures developed at the implantation sites and resulted in impaired renal function. In the two renal units without strictures, no impairment of kidney function was found. Involuntary leak from the anus was not observed and no masceration was found around the anus. These experiments are regarded as very encouraging an a clinical trial is now under way.

Animals↗