Krambeck, Amy E.

Objectives To evaluate short‐term outcomes of holmium laser enucleation of the prostate ( HoLEP ) and photoselective vaporisation of the prostate ( PVP ) in patients with benign prostatic hyperplasia (BPH) and chronic urinary retention ( CUR ). Patients and Methods A retrospective chart review was performed of all patients with CUR who underwent HoLEP or PVP at our institution over a 3‐year period. CUR was defined as a persistent post‐void residual urine volume ( PVR ) of >300 mL or refractory urinary retention requiring catheterisation. Results We identified 72 patients with CUR who underwent HoLEP and 31 who underwent PVP . Preoperative parameters including median catheterisation duration (3 vs 5 months, P = 0.71), American Urological Association Symptom Index score ( AUASI ; 18 vs 21, P = 0.24), and PVR (555 vs 473 mL, P = 0.096) were similar between the HoLEP and PVP groups. The HoLEP group had a larger prostate volume (88.5 vs 49 mL, P < 0.001) and higher PSA concentration (4.5 vs 2.4 ng/mL, P = 0.001). At median 6‐month follow‐up, 71 (99%) HoLEP patients and 23 (74%) PVP patients were catheter‐free ( P < 0.001). Of the voiding patients, postoperative AUASI (3 vs 4, P = 0.06), maximum urinary flow rate (23 vs 18 mL/s, P = 0.28) and PVR (56.5 vs 54 mL, P = 1.0) were improved in both groups. Conclusions Both HoLEP and PVP are effective at improving urinary parameters in men with CUR . Despite larger prostate volumes, HoLEP had a 99% successful deobstruction rate, thus rendering patients catheter‐free.

The sequence of events by which primary hyperoxaluria type 1 (PH1) causes renal failure is unclear. We hypothesize that proximal tubule (PT) is vulnerable because oxalate secretion raises calcium oxalate (CaOx) supersaturation (SS) there, leading to crystal formation and cellular injury. We studied cortical and papillary biopsies from two PH1 patients with preserved renal function, and seven native kidneys removed from four patients at the time of transplant, after short-term ( 2 ) or longer term ( 2 ) dialysis. In these patients, and another five PH1 patients without renal failure, we calculated oxalate secretion, and estimated PT CaOx SS. Plasma oxalate was elevated in all PH1 patients and inverse to creatinine clearance. Renal secretion of oxalate was present in all PH1 but rare in controls. PT CaOx SS was >1 in all nonpyridoxine-responsive PH1 before transplant and most marked in patients who developed end stage renal disease (ESRD). PT from PH1 with preserved renal function had birefringent crystals, confirming the presence of CaOx SS, but had no evidence of cortical inflammation or scarring by histopathology or hyaluronan staining. PH1 with short ESRD showed CaOx deposition and hyaluronan staining particularly at the corticomedullary junction in distal PT while cortical collecting ducts were spared. Longer ESRD showed widespread cortical CaOx, and in both groups papillary tissue had marked intratubular CaOx deposits and fibrosis. CaOx SS in PT causes CaOx crystal formation, and CaOx deposition in distal PT appears to be associated with ESRD. Minimizing PT CaOx SS may be important for preserving renal function in PH1.