Acute renal failure: outcomes and risk of chronic kidney disease

Acute renal failure (ARF) is a common condition, especially among the critically ill, and confers a high mortality. The incidence of ARF is increasing. Efforts such as the Acute Dialysis Quality Initiative (ADQI) are being undertaken to establish a consensus definition of ARF, and to distinguish between varying degrees of acute kidney injury that might confer a different prognosis. Data are emerging to allow comparison of the epidemiology of ARF across institutions internationally. There is ongoing recognition of the important interaction between ARF and chronic kidney disease and more information regarding recovery from ARF is available. Controversy exists regarding the optimal management of ARF. Recent publications emphasize the importance of timing and dose of renal replacement therapy rather than the modality of treatment (intermittent hemodialysis vs continuous therapies). These issues are explored in this review.

Calcification of Glutaraldehyde Cross-Linked Collagen in Bladder Neck Injections in Children With Incontinence: A Long-Term Complication

PURPOSE

We report the incidence of calcifications developing at the bladder neck/urethra in pediatric patients treated with glutaraldehyde cross-linked collagen for urinary incontinence.

MATERIALS AND METHODS

We reviewed charts of patients treated with glutaraldehyde cross-linked collagen injections for urinary incontinence between 1994 and 1999. Etiology of incontinence, pertinent medical history, operative details and postoperative imaging were examined.

RESULTS

Of 31 patients 4 (13%) had development of submucosal calcifications in the bladder neck/urethra. All 4 patients had received multiple injections of glutaraldehyde cross-linked collagen for incontinence secondary to neurogenic bladder. The calcifications were confirmed surgically. Pathology reports available for 2 of 4 patients showed chronic inflammation without dysplasia or malignant changes. Mean followup was significantly different between calcified and noncalcified cases (10.3 vs 7.2 years, p = 0.009), as was total volume of collagen injected (21 vs 12 cc, p = 0.012). Mean time to diagnosis of calcifications was 8.8 years (range 7 to 11) after first injection. A total of 24 patients without calcification underwent bladder imaging at a mean of 6.8 years (+/-2.2) after glutaraldehyde cross-linked collagen injection, which was not significantly different than the time to diagnosis (p = 0.089). The number of injections was not significantly different between the 2 groups (p = 0.426).

CONCLUSIONS

Of our patients 13% had development of calcifications at the site of prior glutaraldehyde cross-linked collagen injections for incontinence. These calcifications were surrounded by chronic inflammation. Patients who have undergone glutaraldehyde cross-linked collagen injections may benefit from long-term followup with bladder imaging to detect and follow calcifications at prior injection sites.

Cutaneous metastases from transitional cell carcinoma of the bladder

Cutaneous metastases from primary genitourinary malignancies are rare and usually represent a poor prognostic sign. Very few cases of skin metastases from urothelial carcinoma have been reported in the past, and most of them were treated with chemotherapy. We report a patient with transitional cell carcinoma of the bladder who developed skin metastases after cystectomy. The lesions did not respond to systemic chemotherapy but resolved with local radiation therapy. We discuss the need to have a high index of suspicion to identify these lesions and the treatment approaches.

Long-term efficacy of periurethral collagen injection for the treatment of urinary incontinence secondary to myelomeningocele

PURPOSE

The reports of efficacy of periurethral collagen injection (Contigen, Bard, Covington, Georgia) for treatment of urinary incontinence in the myelomeningocele population are limited and variable. We reviewed the efficacy of periurethral collagen in patients with myelomeningocele to provide long-term followup data.

MATERIALS AND METHODS

From 1994 to 1999, 19 children and 6 adults with myelomeningocele underwent periurethral injections of collagen with an average of 2 treatments per patient. Mean followup +/- SD from last injection in the pediatric and adult groups was 2.9 +/- 1.5 years and 4.7 +/- 2.6 years, respectively. Postoperative continence was defined as dry, improved or unchanged.

RESULTS

No pediatric patients became dry, 7 (37%) improved and 12 (63%) were unchanged. A single adult was dry (17%), 4 (67%) improved and 1 remained unchanged. Transient improvement was noted in 8 of the 13 patients who reverted to an unchanged status. Response rate was 66% in nonambulatory patients versus 42% in ambulatory patients (p = 0.38). Of 12 patients who responded and 13 who did not 8 in each group required 2 or more treatments. The responding group percentage of predicted bladder capacity was 97.6% versus 89.5% in those who remained unchanged (p = 0.66).

CONCLUSIONS

The initial transient improvement following collagen injection and the long-term improvement following repeat injections suggest that degradation of collagen decreased its efficacy. The long-term results of this minimally invasive technique are poor.

Long-term efficacy of periurethral collagen injection for the treatment of urinary incontinence secondary to myelomeningocele

PURPOSE

The reports of efficacy of periurethral collagen injection (Contigen, Bard, Covington, Georgia) for treatment of urinary incontinence in the myelomeningocele population are limited and variable. We reviewed the efficacy of periurethral collagen in patients with myelomeningocele to provide long-term followup data.

MATERIALS AND METHODS

From 1994 to 1999, 19 children and 6 adults with myelomeningocele underwent periurethral injections of collagen with an average of 2 treatments per patient. Mean followup +/- SD from last injection in the pediatric and adult groups was 2.9 +/- 1.5 years and 4.7 +/- 2.6 years, respectively. Postoperative continence was defined as dry, improved or unchanged.

RESULTS

No pediatric patients became dry, 7 (37%) improved and 12 (63%) were unchanged. A single adult was dry (17%), 4 (67%) improved and 1 remained unchanged. Transient improvement was noted in 8 of the 13 patients who reverted to an unchanged status. Response rate was 66% in nonambulatory patients versus 42% in ambulatory patients (p = 0.38). Of 12 patients who responded and 13 who did not 8 in each group required 2 or more treatments. The responding group percentage of predicted bladder capacity was 97.6% versus 89.5% in those who remained unchanged (p = 0.66).

CONCLUSIONS

The initial transient improvement following collagen injection and the long-term improvement following repeat injections suggest that degradation of collagen decreased its efficacy. The long-term results of this minimally invasive technique are poor.

Time-varying magnetic fields: effects of orientation on chondrocyte proliferation

The purpose of this study was to determine the effect of orientation of pulsed electromagnetic fields (PEMFs) on cellular proliferation and extracellular matrix synthesis. Bovine articular chondrocytes were cultured in PEMFs (repetitive pulse at 72 Hz) generated using Helmholtz coils oriented either parallel (horizontal) or perpendicular (vertical) to the plane of cell adhesion. Dissipation of signal energy in the form of heat increased the temperature of the PEMF coils by 2 degrees C and the tissue culture medium by 1 degree C. Therefore, control coils, which emitted no PEMFs, were heated to the temperature of PEMF coils by circulating water. Chondrocytes were cultured in 16-mm-well culture plates, and the data for individual wells were pooled as triplicates. Although not observed by microscopic examination of individual wells, positionally dependent electric field effects may be minimized by this approach. PEMFs generated by coils oriented vertically significantly decreased chondrocyte proliferation. The effect was dependent on the concentration of serum in the culture media. At 3% serum concentration, the total cell number attained after 10 days of culture was reduced by 50% in stimulated cultures when compared with controls. At 5% serum concentration, there was no effect. PEMFs applied by coils oriented horizontally did not alter proliferation of articular chondrocytes. PEMFs had no effect on synthesis of extracellular matrix by chondrocytes plated at high density, irrespective of orientation.