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K A Kropp

Publications and source records attributed to K A Kropp.

At least 19 recordsLinked to original sources
PubMed2000

Pediatric urolithiasis in sub-saharan Africa: a comparative study in two regions of Cameroon.

OBJECTIVE: To determine the composition of caculi and the predisposing factors for stone nucleation and growth in children from two regions of Cameroon. METHODS: This was a cross-sectional study involving 21 children, 17 from the northern and 4 from the southern region, over a 6-year period. Data on age, diet, residence, clinical presentation, location of stone, and results of stone analysis were collated following a preestablished proforma. A computerized analysis of the data was carried out. The constituents of stone sections and nidus were assembled so as to determine the principal causes of stone nucleation and growth. RESULTS: Pediatric urolithiasis was more common in the northern Sahelian belt of Cameroon. Males and rural dwellers were more commonly affected. Endemic (bladder) stone disease was found in the majority of the patients. All stones were mixed. The most frequent constituents of the stones were ammonium urate, struvites, and whewellite in descending order of percentage mean volume per stone. The nidus was available for study in only 10 stones, and its composition revealed heterogeneity of causes of nucleation. The commonest cause for stone formation and growth were infection and hyperuricosuria (malnutrition). CONCLUSIONS: Pediatric bladder stone disease is not uncommon in northern Cameroon. Many factors combined to predispose to stone nucleation and growth, but the level of socioeconomic development was preponderant. Stone composition indicated that urolithiasis in children was a heterogeneous disorder, but hyperuricosuria, insufficient diuresis, and infection associated with malnutrition seemed to be the most common causes.

Adolescent↗
PubMed1999

Bladder neck reconstruction in children.

Bladder neck reconstruction in children is a challenging undertaking. Goals must be established for each patient, either continence or dryness. Knowledge of the various types of bladder neck reconstructive procedures and what they are designed to do is important when considering bladder neck reconstruction. A detailed description of urethral lengthening, reimplantation, and other bladder neck reconstructive procedures is presented.

Child↗
PubMed1997

Urethral lengthening and reimplantation: incidence and management of catheterization problems.

PURPOSE: Creation of a 1-way catheterizable valve has resulted in dryness for a large group of children with intractable urinary incontinence. We document the incidence, time course and management of catheterization problems in 49 children who underwent urethral lengthening and reimplantation for intractable incontinence. MATERIALS AND METHODS: We reviewed the records of 21 boys and 28 girls who underwent urethral lengthening and reimplantation between 1982 and 1995. Catheterization problems were defined as the inability of the patient or a family member to pass the catheter, and divided into early only, late only, recurrent and persistent problems. RESULTS: Of the 49 patients 46 had neurogenic incontinence secondary to myelomeningocele and 35 (72%) never had difficulty catheterizing. Of the 14 children (28%) who had difficulty 7 (50%) were boys and 7 (50%) were girls. Two children (4%) with early only difficult catheterization have had no further difficulties during the last 14 and 6 years, respectively. In 3 children (6%) late only difficult catheterization began 17, 24 and 35 months, respectively, after the original bladder neck surgery. These problems were solved by changing to a Coudé catheter and/or avoiding over distension. The 7 patients (14%) with recurrent catheterization problems, some with long intervals between episodes, now catheterize easily. The 2 children (4%) with persistent problems required alternate access to the bladder. CONCLUSIONS: The majority of children (72%) who undergo urethral lengthening and reimplantation never have any difficulty catheterizing. Those in whom difficult catheterization develops can be treated with minimally invasive methods without compromising the goals of the original surgery.

Child↗
PubMed1996

Proximal ureteral stent migration: an avoidable complication?

PURPOSE: The parameters responsible for proximal ureteral stent migration were quantitated. MATERIALS AND METHODS: We compared 16 patients seen between 1990 and 1993 with stent migration to 32 patients whose stents did not migrate. RESULTS: The stent indwelling time and number of stents with a proximal curl of less than 180 degrees were similar between the groups. More patients with migration had stents that were shorter than the ideal length, with a distal curl of less than 180 degrees and a proximal curl in the upper calix versus the renal pelvis. CONCLUSIONS: A shorter than ideal stent, inadequate distal curl and a proximal curl in the upper calix appear to be significant factors in the process of stent migration.

Case-Control Studies↗
PubMed1995

Use of ileal urinary diversion in conjunction with intraoperative radiotherapy.

Intraoperative radiotherapy (IORT) was introduced in the 1970s as a new modality of cancer therapy. It has been especially useful after local irradiation or surgical failure. We report on the use of IORT in 13 patients with pelvic tumors requiring urinary diversion. All 13 were managed with ileal conduits. Despite the associated problems of prior abdominal procedures (11/13 patients), prior external beam radiation to the pelvis (11/13 patients), systemic chemotherapy (4/13 patients), and prolonged operative time (> 10 hours), perioperative mortality (1/13) and morbidity rates were low. We conclude that in cases of prior colonic resection and pelvic radiation, potentially irradiated ileum can be safely used for urinary diversion.

Aged↗
PubMed1995

Prostate cancer.

Explore the source record for details and available documents.

Humans↗
PubMed1994

Photochemical ablation of intestinal mucosa for bladder augmentation.

Complications associated with enterocystoplasty include mucus production, electrolyte abnormalities, infections, stones and cancer at the vesicoenteric anastomosis. Removal of the intestinal mucosa with subsequent urothelialization may obviate these problems. We describe a unique approach whereby photodynamic therapy is used to de-epithelialize an ileal segment before augmentation. Enterocystoplasty was performed in 32 female Fischer 344 rats using a 1.5 cm. patch of terminal ileum. Of the 32 rats 24 survived at least 6 weeks before euthanasia. The experimental group (10 rats) received hematoporphyrin derivative intravenously 24 hours before surgery. The ileal patch was treated with red light for 20 minutes and then used for augmentation. There were 3 control groups, including 1 group of 5 rats that underwent augmentation alone, while the other 2 groups were augmented but received either light treatment (4 rats) or hematoporphyrin derivative (5 rats). Histological analysis revealed urothelialization of the augments treated with hematoporphyrin derivative and light, which did not occur in the controls. The preoperative and postoperative bladder capacities increased substantially in all groups. Mucus production and bacterial colonization were reduced while stone formation increased in the treated animals.

Animals↗
PubMed1994

Conservative management of suspected bladder rupture after augmentation enterocystoplasty.

Bladder rupture after augmentation enterocystoplasty is a potentially life-threatening condition. We reviewed our experience with 13 patients who presented to our institution with 15 episodes of sudden onset of abdominal pain and rebound tenderness, and were diagnosed on clinical grounds to have peritonitis secondary to a suspected bladder augmentation rupture. (Three patients had had similar episodes treated previously elsewhere with abdominal exploration and repair of an augmentation rupture.) These episodes were initially managed with hospitalization, bladder drainage with an indwelling catheter, intravenous antibiotics and serial abdominal examinations. Cystogram and/or computerized tomography was diagnostic in only 3 of 7 cases in which it was performed. In 13 of 15 instances signs and symptoms of peritonitis quickly resolved, and intermittent catheterization was resumed after a mean of 12 days. In the remaining 2 patients delayed surgical repair of a bladder rupture was done in 1, and exploration and repair of an incarcerated internal hernia were done in 1. Although prompt abdominal exploration is the gold standard for suspected bladder augmentation rupture, treatment of peritonitis as bladder rupture in patients with a bladder augmentation by nonoperative techniques was successful in 87% of episodes.

Adolescent↗
PubMed1994

Cyclosporine versus azathioprine: a 5-year followup of 200 consecutive cadaver renal transplant recipients.

When cyclosporine was introduced as an immunosuppressive agent, there was concern that cyclosporine could be detrimental to long-term renal allograft function and survival. In response to this concern, we report a 5-year followup of 200 consecutive renal transplant recipients among whom initial immunosuppression and risk factors were similar except for the substitution of cyclosporine for azathioprine in the second 100 recipients. The azathioprine and cyclosporine groups had similar 1-year (89% versus 91%) and 5-year (74% versus 80%) patient survival rates. Cyclosporine treated patients had superior 1-year (83% versus 58%) and 5-year (61% versus 29%) graft survival rates. At the 5-year interval, cyclosporine treated grafts had an elevated, yet stable, mean serum creatinine level compared to azathioprine treated grafts. Despite ongoing mild renal dysfunction in cyclosporine treated grafts, cyclosporine does not induce an inexorable decrease in graft function and continues to provide long-term graft survival superior to azathioprine.

Azathioprine↗
PubMed1993

The hyponatremia of neonatal urinary ascites: clinical observations, experimental confirmation and proposed mechanism.

A case of neonatal urinary ascites with severe hyponatremia is reported. Critical review of the literature on neonatal urinary ascites, which included determination of serum electrolytes, revealed a 70% incidence of hyponatremia. In an attempt to explain the mechanism of the hyponatremia, urinary ascites was produced in rats by creation of either a unilateral (uretero-peritoneal) or bilateral (vesicoperitoneal) shunt. Hyponatremia did not occur in the unilateral group but it was profound in the bilateral group. At 48 hours postoperatively renin was unchanged in the unilateral group but it was significantly elevated in the bilateral group. Aldosterone was elevated in the unilateral group and markedly elevated in the bilateral group. Urine entering the peritoneal cavity equilibrates with plasma. The proposed mechanism of hyponatremia in the bilateral group is autodialysis with intraperitoneal urine containing progressively lower sodium concentration secondary to increased renin and aldosterone.

Aldosterone↗
PubMed1992

A new technique for bladder washing.

We describe a simple adaptation of the Water Pik (Teledyne Water Pik, Fort Collins, Colorado) irrigating device which allows vigorous, direct-vision agitation of the bladder wall. Three groups of mongrel dogs were subjected to cystoscopy and either syringe barbotage, half-speed Water Pik irrigation, or full-speed Water Pik irrigation of the bladder wall. Transitional cell counts were then done on centrifuged aliquots of each bladder wash specimen. The average number of transitional cells per high-power field were similar between the control group and the syringe barbotage group (2.5 and 1.5 respectively). However, both the half-speed and the full-speed Water Pik groups demonstrated statistically higher cell counts (5.7 and 13.7) when compared to both the controls and syringe barbotage groups. We conclude that Water Pik irrigation is an effective method to increase cell yield in bladder wash specimens.

Animals↗
PubMed1991

Urodynamic evaluation of the continence mechanism following urethral lengthening--reimplantation and enterocystoplasty.

In an attempt to create continence in myelomeningocele children we performed urethral lengthening/submucosal reimplantation, a form of bladder neck reconstruction, to create a valve allowing catheterizable access to the bladder. We present the urodynamic findings of 23 patients 4 to 89 months (mean 43.1 months) after bladder neck reconstruction and enterocytoplasty to determine the continence mechanism of this 1-way valve and characteristics of the augmented bladder. Standard cystometrograms with simultaneous pressure recording of the submucosal portion of the neourethra were undertaken with a 10F, triple lumen, urethral pressure profile catheter. Baseline pressures in the submucosal neourethra were higher than in the bladder (mean 25.3 versus 13.4 cm, water, p less than 0.001). Submucosal tunnel and bladder pressures paralleled throughout filling, with mean tunnel pressures remaining greater at the time of first (53.6 versus 45.5 cm. water, p less than 0.01) and peak (62.9 versus 55.8 cm. water, p greater than 0.05) cystoplasty contractions. Bladders augmented with detubularized ileum had fewer significant contractions (greater than 40 cm. water) than other types of cystoplasties (36% versus 92%) and over-all they had first and peak contractions at greater volumes and lesser magnitude. We conclude that continence following urethral lengthening/reimplantation results from an anatomical arrangement allowing transmission of dynamic bladder pressure changes to the submucosal neourethra and that urethral pressure exceeds bladder pressure throughout filling. Additionally, our data suggest that detubularized ileum provides a large capacity, low pressure reservoir suitable for augmentation.

Adolescent↗
PubMed1990

Management of urinary incontinence by bladder tube urethral lengthening and submucosal reimplantation.

We reviewed the first 25 urethral lengthening and reimplantation procedures done at our institution in 24 patients. All patients had failed to achieve dryness on medical or surgical therapy for total urinary incontinence. A total of 32 patients had neurogenic incontinence. The patients were followed for 1.5 to 7 years. Late complications included catheterization difficulties, vesicoureteral reflux, febrile urinary tract infection, calculi and peritonitis. Reoperations were required in 19 patients primarily because of our initial failure to recognize the necessity of providing a low pressure, high capacity reservoir. The reoperation rate on the continence mechanism was low. Of 24 patients 20 are continent and require no pads or diapers.

Adolescent↗
PubMed1990

Effects of hypothermia on testicular ischemia.

The ischemic effects of prolonged testicular torsion have been well documented; however, prevention or arrest of the damaging effects of prolonged ischemia has been incompletely studied. Two groups of Sprague-Dawley rats were subjected to varying lengths of bilateral testicular ischemia. Group I underwent normothermic ischemia for two, four, and six hours. Likewise, Group II underwent similar time periods of ischemia, however, after thirty minutes of normothermic ischemia the scrotum of each animal was placed into an ice bath maintained at 4C. Two weeks postoperatively, bilateral orchiectomy was performed. Histology of the testes of the two groups was compared. Neither group revealed significant destruction of the germinal epithelium after two hours of ischemia. Group I revealed only 25% preservation of the germinal epithelium at four hours and only 8% preservation at six hours of ischemia. In contrast, Group II which received ice showed 90% preservation of germinal epithelium at four hours and 85% preservation at six hours of ischemia. We conclude that external ice application significantly preserves seminiferous tubules at four and six hours of ischemic injury in the rat testicle.

Animals↗
PubMed1989

Cyclosporine versus azathioprine: a review of 200 consecutive cadaver renal transplant recipients.

Most renal transplant centers report an increase in graft survival when cyclosporine is used as a primary immunosuppressant. We report the outcome of 200 consecutive cadaver renal transplant recipients among whom initial immunosuppression and risk factors were similar except for the substitution of cyclosporine for azathioprine in the second 100 recipients. Azathioprine-treated recipients had significantly increased (p less than 0.05) mean hospital stays (31.9 versus 18.3 days), incidence of first rejection episodes (85 versus 31) and methylprednisolone dose (3.38 versus 0.06 gm. per patient). Cyclosporine-treated recipients had a significantly higher 1-year mean serum creatinine level (1.85 versus 1.56 mg. per dl.) and 1-year actual graft survival (83 versus 58 per cent). Despite mild nephrotoxicity, cyclosporine is superior to azathioprine as a primary immunosuppressant in cadaver kidney transplantation.

Azathioprine↗