Sven Oehlschläger

Impact of resection margin status after nephron-sparing surgery for renal cell carcinoma

To evaluate whether the negative‐margin width after nephron‐sparing surgery for renal cell carcinoma (RCC) is associated with tumour recurrence.

Comparison of Transperitoneal versus Retroperitoneal Approach in Laparoscopic Radical Nephrectomy for Renal Cell Carcinoma: A Single-Center Experience of 63 Cases

Background: We report our experience with the retroperitoneal (RP) and transperitoneal (TP) approaches for laparoscopic nephrectomy for clinically localized renal cell carcinoma. Methods: Sixty-three patients with renal cell carcinoma were treated with laparoscopic nephrectomy, 34 by TP and 29 by RP approach between June 1999 and June 2003. Average age, ASA score, tumor stage and tumor size were similar in both groups. Early complications within 30 days and surgical time were retrospectively reviewed. Results: Surgical time was with a mean of 183 and 190 minutes equal for the TP and RP approach. Intraoperative complications occurred in 4 patients and were vascular, requiring blood transfusion in 2 patients each per group. Postoperative complications were thromboembolism in 1 patient and subcutaneous seroma in 1 patient, both in the TP group. Conclusions: Although the sample size is small, it appears that the tumor control and surgical time in laparoscopic nephrectomy are not significantly influenced by the approach.

Surgery for renal cell cancer extending into the inferior vena cava - evaluation of survival and perioperative complications using a standardized classification system.

Study Type – Therapy (case series)

Distal Ureteral Stenosis after Early Adjuvant Intravesical Mitomycin C Application for Superficial Bladder Cancer

We report a case of distal ureteral stenosis after transurethral resection of a small bladder tumor near the left ureteral orifice and early postoperative mitomycin C instillation for prevention of recurrence. The patient developed late recurrent stenosis of the ureteral orifice with histologic evidence of localized, severe benign inflammatory reaction. The recurrent stenosis was successfully managed by transurethral resection of the scar tissue and ureteric stenting. Although ureteral stenosis does occur after transurethral resection, the severity and time course of the stenosis in this case suggest an influence of the intravesical chemoprophylaxis used.

Bladder Tumor Recurrence after Primary Surgery for Transitional Cell Carcinoma of the Upper Urinary Tract

Objective: Primary transitional cell carcinoma (TCC) of the upper urinary tract represents 6–8% of all TCC cases. Nephroureterectomy with removal of a bladder cuff is the treatment of choice. The rates of TCC recurrence in the bladder after primary upper urinary tract surgery described in the literature range between 12.5 and 37.5%. In a retrospective analysis we examined the occurrence of TCC after nephroureterectomy for upper tract TCC in patients without a previous history of bladder TCC at the time of surgery. Methods: Between 1990 and 2002, 29 patients underwent primary nephroureterectomy for upper tract TCC. The mean age of the patients was 69.5 years. In 5 cases upper urinary tract tumors were multilocular, in the remaining cases unilocular in the renal pelvis (n = 12) or the ureter (n = 12). The follow-up was available for 29 patients with a mean follow-up of 3.37 (0.1–11.2) years. Results: 11/29 (37.9%) patients had TCC recurrence with 9/11 patients having bladder TCC diagnosed within 2.5 years (0.9–6.0) after nephroureterectomy. 13/29 patients are alive without TCC recurrence, 3/29 patients died due to systemic TCC progression and 5/29 died of unrelated causes without evidence of TCC recurrence. Conclusion: Our data indicate a high incidence of bladder TCC after nephroureterectomy for primary upper tract TCC of up to 6 years after primary surgery. Because of the high incidence of bladder TCC within the first 3 years of surgery, careful follow-up is needed over at least this period.

Evaluation of Chemical Composition of Urinary Calculi by Conventional Radiography

BACKGROUND AND PURPOSE The choice of the most efficient treatment modality for renal calculi could be facilitated by determining the precise chemical stone composition before treatment. We investigated the possibility of using conventional X-ray imaging to determine stone composition and to find a simple method of predicting stone fragility for treatment planning. MATERIALS AND METHODS The X-ray density of 92 stones with known infrared spectroscopy analyses (calcium oxalate monohydrate, calcium oxalate dihydrate, struvite, and calcium phosphate) was retrospectively investigated by scanning the films with a digital camera. The data analysis was done using a commercially available graphics program to compare the total gray-scale levels of the stones. RESULTS There was a significant difference in the mean gray-scale level of calcium phosphate and calcium oxalate stones (P < 0.01). The mean gray-scale difference between calcium oxalate dihydrate and calcium oxalate monohydrate was also significant (p < 0.02). All calcium oxalate, struvite, and calcium phosphate stones were correctly identified. Of the calcium oxalate monohydrate and calcium oxalate dihydrate stones, 98.4% and 66.6%, respectively, were correctly identified. CONCLUSION The method allows a reliable diagnosis of stone composition from radiographs, which can be useful in stone treatment planning.

Nephron-sparing surgery for renal cell carcinoma in the solitary kidney

Objective. Partial nephrectomy in solitary kidneys carries the risk of tumour progression as well as loss of renal function. We evaluated complications and outcome in patients with renal cell cancer in solitary kidneys who were treated by means of nephron-sparing surgery. Material and methods. Between 1993 and 2003, 38 patients with renal cell carcinoma in a solitary kidney underwent nephron-sparing surgery (partial nephrectomy, n=37; work-bench resection, n=1). Of these patients, 21 had asynchronous and eight had synchronous bilateral tumours and underwent contralateral radical nephrectomy. The variables examined were tumour size, disease progression, pre- and postoperative renal function and early (within 30 days of nephron-sparing surgery) and late complications. Results. After a mean follow-up period of 41.7 months (range 8–93 months) the mean serum creatinine level had increased from 1.25 mg/dl preoperatively to 1.62 mg/dl postoperatively. Seventeen patients retained normal renal function and 21 developed some degree of renal insufficiency. New-onset chronic renal insufficiency after nephron-sparing surgery with creatinine levels >2 mg/dl was the only late complication observed, occurring in 10 cases. None of the patients required dialysis. Transient urinary leakage was the most frequent early complication, occurring in four cases. Recurrence and/or progression were seen in six patients: four with local recurrence (three of whom also had distant metastases) and two with pure metastatic progression. Nephron-sparing surgery was repeated for the patient with isolated local tumour recurrence. The mean tumour size was 3.8 cm (range 0.7–9.9 cm). Tumour size was markedly greater in patients who developed disease progression (6.2 vs 3.5 cm) and in those who developed renal insufficiency (5.2 vs 3.3 cm). Conclusions. Nephron-sparing surgery for renal cell carcinoma involving a solitary kidney provides effective curative treatment for small tumours, with preservation of renal function. However, patients who undergo partial nephrectomy for locally extensive tumours are at high risk of disease progression.

Early changes of oxalate and calcium urine excretion in those with calcium oxalate stone formation after extracorporeal shock wave lithotripsy

OBJECTIVES To determine the extent of transient changes of tubular function in idiopathic calcium-oxalate (CaOx) stone-bearing patients after extracorporeal shock wave lithotripsy (ESWL), calcium and oxalate excretion were measured before and after ESWL. METHODS In 22 patients with renal CaOx stones, the plasma values and urine excretion of creatinine, calcium, oxalate, magnesium, and citrate were measured before and on days 1 and 2 after ESWL under conditions of a standardized diet. Overnight urine collection for an 8-hour period was used to measure the urine excretion, and the values were extrapolated to a 24-hour period. For calculation of the urine ion activity, the AP(CaOx) index EQ(s) and the CaOx risk index were used. RESULTS After ESWL, hyperoxaluria was noted in 10 patients compared with 2 before ESWL. Hypercalciuria was seen in 11 patients after ESWL compared with 3 before. Combined hyperoxaluria and hypercalciuria was found in 7 patients after ESWL compared with 1 before. Both the oxalate/creatinine and calcium/creatinine ratios were significantly increased after ESWL. The AP(CaOx) index EQ(s) and the CaOx risk index were significantly increased after ESWL in patients with increased post-ESWL calcium and/or oxalate excretion. CONCLUSIONS Increased calcium and/or oxalate excretion can be seen in patients with CaOx stones early after ESWL. This increased excretion of lithogenic substances represents an increased risk of fragment apposition after ESWL for the group with a significantly increased AP(CaOx) index EQ(s) and CaOx risk index. Therefore, prophylactic measures in patients at risk early after ESWL might be warranted to prevent possible recurrent stone formation.

Role of Cellular Oxalate in Oxalate Clearance of Patients With Calcium Oxalate Monohydrate Stone Formation and Normal Controls

OBJECTIVES To examine the cellular, plasma, and urinary oxalate and erythrocyte oxalate flux in patients with calcium oxalate monohydrate (COM) stone formation vs normal controls. Pathologic oxalate clearance in humans is mostly integrated in calcium oxalate stone formation. An underlying cause of deficient oxalate clearance could be defective transmembrane oxalate transport, which, in many tissues, is regulated by an anion exchanger (SLC26). METHODS We studied 2 groups: 40 normal controls and 41 patients with COM stone formation. Red blood cells were divided for cellular oxalate measurement and for resuspension in a buffered solution (pH 7.40); 0.1 mmol/L oxalate was added. The supernatant was measured for oxalate immediately and 1 hour after incubation. The plasma and urinary oxalate were analyzed in parallel. RESULTS The mean cellular oxalate concentrations were significantly greater in the normal controls (5.25 +/- 0.47 micromol/L) than in those with COM stone formation (2.36 +/- 0.28 micromol/L; P < .01). The mean urinary oxalate concentrations were significantly greater in those with COM stone formation (0.31 +/- 0.02 mmol/L) than in the controls (0.24 +/- 0.02 mmol/L; P < .01). The cellular oxalate concentrations correlated significantly with the plasma (r = 0.49-0.63; P < .01) and urinary oxalate (r = -0.29-0.41; P < .03) concentrations in both groups. The plasma oxalate concentrations correlated significantly with the urinary oxalate concentrations (r = -0.30; P < .03) in the controls and with the erythrocyte oxalate flux (r = 0.25; P < .05) in those with COM stone formation. CONCLUSIONS Our data implicate the presence of a cellular oxalate buffer to stabilize plasma and urinary oxalate concentrations in normal controls.

Importance of Erythrocyte Band III Anion Transporter (SLC4A1) on Oxalate Clearance of Calcium Oxalate Monohydrate Stone-formering Patients vs. Normal Controls

OBJECTIVES To examine erythrocyte band III transport protein (SLC4A1), erythrocyte oxalate flux, and plasmatic, cellular, and urine oxalate concentrations and blood gas analyses in calcium oxalate monohydrate stone-forming patients (COM) in comparison with normal controls (NC). METHODS Isolated red cells from 51 NC and 25 COM cases were divided for cellular oxalate measurement and for measurement of transcellular erythrocyte oxalate flux (pH 7.48-8.24). SLC4A1 protein levels were determined by Western blot analyses. Plasmatic and urinary oxalate levels and the venous blood gas analysis were measured simultaneously. RESULTS SLC4A1 protein levels were significantly higher in COM (8.76 ± 2.12) than in NC (4.17 ± 0.61; P < .02). Cellular oxalate and venous HCO(3)(-) were significantly lower in COM (2.35 ± 0.26 μmol/L) and (24.06 ± 0.24 mmo/l) than in NC (4.03 ± 0.49 μmol/L; P < .05) and (24.93 ± 0.17 mmol/L; P < .01). Urinary oxalate was significantly higher in COM (0.31 ± 0.02 mmol/L) than in NC (0.25 ± 0.01 mmol/L; P < .04). The erythrocyte transmembrane oxalate flux correlated with the pH value and with the urinary oxalate in both groups (r = .25-.55; P = .01). With increased pH values, the oxalate flux showed inverse effects in both groups. CONCLUSIONS SLC4A1 associated changes of HCO(3)(-) and pH levels influenced the cellular oxalate levels and urinary oxalate clearance. Under normal conditions (pH 7.55) the oxalate efflux in COM was comparable with the acid stimulated oxalate efflux in NC. The addition of HCO(3)(-) compensated the flux of COM stone formers to the levels of normal controls.