Unni M.M. Mooppan

Penile fracture: preoperative evaluation and surgical technique for optimal patient outcome

To review the preoperative diagnostic evaluation and surgical treatment of penile fracture, as the condition is a urological emergency that requires immediate surgical exploration and repair.

Diagnosis and Treatment of Urethral Prolapse in Children: Experience With 34 Cases

OBJECTIVESnTo retrospectively review 34 cases of urethral prolapse at an inner-city institution with an emphasis on diagnosis and treatment in the pediatric population.nnnMETHODSnWe performed a retrospective chart review of 34 patients of all age groups with urethral prolapse treated at our institution and reviewed the relevant published data.nnnRESULTSnA total of 34 patients with urethral prolapse were treated at our institution during a 23-year period. The diagnosis was made mainly by physical examination. The findings from the history, physical examination, and pertinent laboratory investigations were reviewed. Most patients were treated successfully with excision of the prolapsed mucosa circumferentially over a Foley catheter and discharged home within 24 hours of the operation. No major complications occurred.nnnCONCLUSIONSnUrethral prolapse primarily affects premenarchal black girls and should be treated promptly with excision of the prolapsed mucosa and early hospital discharge.

Complications from external (condom) urinary drainage devices

External urinary drainage devices are usually considered safe and are in wide clinical use. There are only a few reports of complications arising from their improper use. We present 6 patients who suffered major complications from external condom drainage at home. The etiology and preventive measures are discussed.

Multi-drug-resistant bacteremia after transrectal ultrasound guided prostate biopsies in hospital employees and their relatives.

OBJECTIVESnTo evaluate the incidence of multi-drug-resistant (MDR) organisms causing bacteremia in hospital employees and their relatives after transrectal ultrasound (TRUS) guided prostate biopsies.nnnMETHODSnWe retrospectively reviewed all TRUS-guided prostate biopsies between November 2006 and November 2007. Of the 378 patients, we identified 4 cases of post-procedure bacteremia requiring hospital admission. All 4 of these patients had MDR organisms causing bacteremia. These patients were then contacted to determine whether they or their relatives were hospital employees.nnnRESULTSnWe identified 4 patients among a total of 378 who developed MDR bacteremia after TRUS prostate biopsy (1.06%). Three of these patients or their relatives were hospital employees (75%). All 3 of these patients had bacteremia caused by Escherichia coli that was resistant to ciprofloxacin and levofloxacin, the perioperative antibiotic given.nnnCONCLUSIONSnIn addition to the standard TRUS biopsy preoperative questions it is beneficial to ask patients whether they are hospital employees or live in the same household as hospital employees. This way, if patients return postoperatively with fever and chills, there is a higher index of suspicion that bacteremia may be caused by MDR organisms and empiric broad spectrum parenteral antibiotics can be started immediately.

Contribution of Endothelin-1 to Renal Vasoconstriction in Unilateral Ureteral Obstruction: Reversal by Verapamil

PURPOSEnIn unilateral ureteral obstruction (UUO) vasoconstriction occurs both during and after release of UUO. ET-1, an endogenous peptide, causes marked vasoconstriction mediated by an increase in cytosolic calcium. We measured renal output of endothelin-1 (ET-1) in dogs with UUO and examined if the renal vasoconstriction that persisted after release of UUO could be reversed by a calcium antagonist, verapamil.nnnMATERIALS AND METHODSnHemodynamic and clearance experiments were performed in anesthetized mongrel dogs in three groups. Group I consisted of 9 dogs with sham-operation. Group 2 consisted of 7 dogs in whom ureteral obstruction was released 1.9 hours after UUO. Group 3 consisted of 5 dogs in whom verapamil was infused into the renal artery at two doses (5 and 10 microg./min., respectively) after release of UUO of 19-hour duration. ET-1 concentrations (measured by radioimmunoassay) were determined for renal venous and arterial plasma.nnnRESULTSnIn Group 1 renal venous plasma ET-1 level was 16.7 +/- 2.2, significantly lowered than 22.8 +/- 3.2 pg./ml. in arterial plasma, indicating a net clearance of ET-1. In Group 2 and 3, renal venous plasma ET-1 levels (28.2 +/- 5.2 and 27.2 +/- 2.4 pg./ml., respectively) were significantly greater than those in arterial plasma (24.2 +/- 5.7 and 17.4 +/- 0.8 pg./ml., respectively), indicating a net output of ET-1 in the kidney, In addition, renal vasoconstriction occurred in Groups 2 and 3 as indicated by significantly lower renal blood flow and GFR than those in Group 1. In Group 3, intrarenal infusion of verapamil at two doses did not change arterial pressure but caused an ipsilateral, significant increase in RBF (from 132 +/- 4 17 to 1.84 +/- 19 and 180 +/- 16 ml./min., respectively) and dose-dependent increases in GFR (from 12 +/- 2 to 25 +/- 3 and 38 +/- 7 ml./min., respectively), associated with a profound dose-dependent ipsilateral diuresis and natriuresis.nnnCONCLUSIONnProfound renal vasoconstriction in UUO was associated with an increase in renal production of ET-1, possibly contributing to renal vasoconstriction, and was reversed by intrarenal infusion of verapamil.

Activation of the Endothelium-Derived Relaxing Factor System in Acute Unilateral Ureteral Obstruction

PURPOSEnTo investigate the effects of 1-arginine, a substrate for nitric oxide (NO) synthase, on renal hemodynamics in acute ureteral obstruction (UUO).nnnMATERIALS AND METHODSnRenal blood flow (RBF) and ureteral pressure (UP) were measured in anesthetized dogs with or without UUO.nnnRESULTSnIn 9 dogs (Group 1), RBF was 212 +/- 13 ml./min. before UUO, and significantly increased to 302 +/- 18 and 268 +/- 9 ml./min. at 90 and 140 min. post-UUO, respectively, associated with a marked increase in UP from 3 +/_ 1 mm. Hg to 73 +/- 5 and 83 +/-2 mm. Hg at 90 and 140 min. post-UUO, respectively. In 6 dogs (Group 2) prostaglandin synthesis was inhibited with meclofenamate (5 mg./kg., i.v.). After UUO, RBF did not change significantly and the increase in UP was markedly attenuated when compared with Group 1, as UP rose only to 27 +/-3 and 34 +/- 4 mm. Hg at 90 and 140 min. post-UUO, respectively. In 6 dogs pre-treated with meclofenamate, L-arginine was infused into the renal artery at 5 mg./kg./min. at 90 min. after UUO (Group 3). Prostaglandin synthesis inhibition prevented renal vasodilation after UUO and significantly attenuated the increase in UP. Upon infusion of L-arginine, RBF and UP rose sharply from 202 +/- 16 ml./min. and 24 +/- 6 mm. Hg to 264 +/- 22 ml./min. and 70 +/- 4 mm. Hg, respectively, at 140 min. post-UUO (p <0.001), values approaching those in Group 1. In sham-operated dogs, L-arginine infusion did not alter RBF in dogs with or without pretreatment with meclofenamate.nnnCONCLUSIONnIn UUO the L-arginine-NO pathway is activated, contributing to renal vasodilation and a marked increase in UP.

Atorvastatin Ameliorates Tubulointerstitial Fibrosis and Protects Renal Function in Chronic Partial Ureteral Obstruction Cases

PURPOSEnTubulointerstitial fibrosis, the histological feature of chronic obstructive nephropathy, is delineated in complete unilateral ureteral obstruction models. Histological changes during chronic partial ureteral obstruction are not well studied. We describe changes in a rat model of partial ureteral obstruction. We examined the effects of atorvastatin on histological alterations, fibrosis and function in this model.nnnMATERIALS AND METHODSnAll rats underwent right nephrectomy. To create partial ureteral obstruction the left ureter was incorporated into the psoas muscle, which was split and reapproximated. Excretory urogram, histology, Western blot of alpha-smooth muscle actin and renal clearance were examined in rats with sham, 14-day or 30-day partial ureteral obstruction. Obstructed rats received a regular or a diet supplemented with 50 mg/kg body weight atorvastatin per day.nnnRESULTSnAt 14 days of partial ureteral obstruction pyelogram showed hydronephrosis, which was more pronounced on obstruction day 30. Histological studies on obstruction days 14 and 30 revealed tubulointerstitial fibrosis in the medulla and cortex. Atorvastatin significantly decreased tubulointerstitial fibrosis seen in alpha-smooth muscle actin expression. On obstruction day 14 or 30 the glomerular filtration rate in rats on a regular diet was significantly lower than in sham PUO rats or rats on atorvastatin.nnnCONCLUSIONSnThis model of partial ureteral obstruction enables chronic studies of morphological and histological changes of the obstructed kidney. It showed progressive fibrosis and decreased filtration function. Atorvastatin ameliorated fibrosis and helped preserve kidney filtration function.

Atorvastatin protects renal function in the rat with acute unilateral ureteral obstruction.

OBJECTIVESnTo examine the effects of atorvastatin on renal hemodynamics and urinary microalbumin levels in rats with acute unilateral ureteral obstruction (UUO). Previous studies have demonstrated that treatment with statins attenuated renal structural damages in rodents with chronic UUO. However, it is not known whether statins afford protection of renal function.nnnMETHODSnUUO was created by ligation of the left ureter in rats maintained on a regular diet or the same diet but supplemented with atorvastatin (50 mg/kg/d) for 2 weeks. Renal clearance experiments were performed after release of UUO at 1 hour, 6 hours, or 12 hours.nnnRESULTSnAtorvastatin treatment lowered plasma triglyceride but not cholesterol levels. Both glomerular filtration rate and effective renal plasma flow were significantly greater in atorvastatintreated rats after release of UUO at 1 hour, 6 hours, and 12 hours. Significant reduction of urinary microalbumin to creatinine ratios occurred in the atorvastatin-treated group at 12 hours but not earlier.nnnCONCLUSIONSnAtorvastatin treatment affords protection of renal function in acute UUO and reduces urinary microalbumin levels without lowering cholesterol levels. This pleiotropic action of atorvastatin on preservation of renal hemodynamics may be important in attenuating subsequent renal structural injury in chronic UUO.

RENAL ACTIONS OF ENDOTHELIN-1 UNDER ENDOTHELIN RECEPTOR BLOCKADE BY BE-18257B

PURPOSEnEndothelin-1 (ET-1), a peptide produced by the vascular endothelium, causes profound renal vasoconstriction by binding to ET-A receptors. The present study examined the renal actions of ET-1 after ET-A receptors were blocked by BE-18257B to unmask the functions of ET-B receptors.nnnMATERIALS AND METHODSnRenal hemodynamics and clearance measurements were obtained in anesthetized dogs after intrarenal infusion of BE-18257B at 100 ng./kg./min. (Group 1), after intrarenal infusion of ET-1 at 2 ng./kg./min. (Group 2), or after intrarenal infusion of ET-1 superimposed on BE-18257B (Group 3).nnnRESULTSnIn Group 1, BE-18257B infusion did not alter arterial pressure, renal blood flow (RBF), GFR or tubular function. In Group 2, ET-1 infusion led to a significant decrease in RBF and GFR (37 and 40%, respectively) without altering arterial pressure. Urinary volume and sodium excretion were not changed but osmolality decreased significantly. In Group 3, BE-18257B infusion significantly attenuated the decrease in RBF caused by ET-1 and increased GFR by 40% without altering arterial pressure, associated with significant diuresis and natriuresis.nnnCONCLUSIONnRenal vasoconstriction caused by ET-1 is attenuated by ET-A receptor blockade with BE-18257B, which unmasks the hemodynamic and tubular actions of ET-B receptors. As a result, it limits the ET-1 induced decrease in RBF and raises GFR, and leads to a diuresis and natriuresis.