J. Stuart Wolf

The Extraperitoneal Approach and Subcutaneous Emphysema are Associated with Greater Absorption of Carbon Dioxide During Laparoscopic Renal Surgery

PURPOSEnWe investigated the association of carbon dioxide absorption with the approach (transperitoneal versus extraperitoneal) and other factors during laparoscopy.nnnMATERIALS AND METHODSnCarbon dioxide elimination during laparoscopic renal surgery was retrospectively calculated in 63 patients.nnnRESULTSnCarbon dioxide elimination increased with time. Multiple factorial analysis revealed that subcutaneous emphysema and the extraperitoneal approach were independently associated with a greater increase in carbon dioxide elimination. Pneumothorax and pneumomediastinum were more common during extraperitoneal procedures.nnnCONCLUSIONSnCarbon dioxide absorption during laparoscopic renal surgery increases with time, and is greatest in patients treated through an extraperitoneal approach and in those with subcutaneous emphysema. Nonetheless, with attentive ventilatory management adverse sequelae of hypercapnia can be avoided.

RETROSPECTIVE ANALYSIS OF THE EFFECT OF CROSSING VESSELS ON SUCCESSFUL RETROGRADE ENDOPYELOTOMY OUTCOMES USING SPIRAL COMPUTERIZED TOMOGRAPHY ANGIOGRAPHY

PURPOSEnUsing spiral computerized tomography (CT) angiography, we sought to evaluate the incidence of a crossing vessel in a group of adults with primary ureteropelvic junction obstruction who had previously undergone successful retrograde endopyelotomy.nnnMATERIALS AND METHODSnA total of 16 patients who had undergone successful Acucise balloon incision endopyelotomy for ureteropelvic junction obstruction, all with followup greater than 2 years, underwent a spiral CT angiogram with intravenous contrast material to identify those with a crossing vessel. Contrast enhanced CT was performed with dual phase technique on a Somatom-Plus-S CT scanner using prototype software. After 180-degree linear interpolation of the projection data, transaxial images of the affected kidney were reconstructed. In addition, at the time of the study all patients completed analog followup pain scales and quality of life assessment questionnaires.nnnRESULTSnAmong the 16 patients 6 (38%) had anterior or posterior crossing vessels based on spiral CT angiography. No patient had both types. By analog pain scale patients had 80% mean improvement in pain (range 63 to 100).nnnCONCLUSIONSnIn our series nearly 40% of patients with anterior or posterior crossing vessels had a long-term (greater than 2 years) successful outcome with retrograde endopyelotomy. Endopyelotomy continues to be our initial mode of therapy among adults with primary ureteropelvic junction obstruction. In our opinion the adverse influence of the crossing vessel is not sufficient to justify the added expense of preoperative angiography, spinal CT or endoluminal ultrasound.

LONG-TERM OUTCOME OF CALICEAL DIVERTICULA FOLLOWING PERCUTANEOUS ENDOSURGICAL MANAGEMENT

PURPOSEnWe review the morbidity and long-term outcome of percutaneous caliceal diverticulectomy and associated stone extraction.nnnMATERIALS AND METHODSnPercutaneous caliceal diverticulectomy was performed in 19 women and 11 men (age range 20 to 58 years), of whom 26 had stones (all 15 mm. or less). The diverticula were located throughout the kidney, including the upper (11 patients), middle (15) and lower (4) calices. Percutaneous caliceal diverticulectomy included 28 direct and 2 indirect accesses (1 via a previously placed nephrostomy tract and 1 due to stones in other areas of the kidney). In all cases the stone was removed and the diverticular neck was incised or dilated. Fulguration of the diverticular walls was performed in 22 cases. Transdiverticular percutaneous renal and ureteral drainage was maintained from 2 to 7 days until a nephrostogram demonstrated no extravasation.nnnRESULTSnThe average operating room time and hospital stay were 171 minutes (range 75 to 330) and 4.1 days (range 2 to 7), respectively. Major complications occurred in 6.6% of the cases, requiring 1 blood transfusion and 1 chest tube placement, and minor complications occurred in 13.4%. There was no mortality. Followup for more than 1 year was available in 27 patients. Stone-free rate was 93% with obliteration of the diverticulum in 76% of patients. Overall, 85% of patients are asymptomatic at average followup of 3.5 years (range 1 to 7.3).nnnCONCLUSIONSnDirect percutaneous endosurgical management provides a safe, efficacious and durable means of treating stone bearing caliceal diverticula, regardless of stone size or location of the diverticulum.

Ureterolysis for Extrinsic Ureteral Obstruction: A Comparison of Laparoscopic and Open Surgical Techniques

PURPOSEnWe evaluated the role of laparoscopy in the management of extrinsic ureteral obstruction due to benign retroperitoneal fibrosis or ovarian pathology. The results of laparoscopic ureterolysis were compared to those of a contemporary series of open ureterolysis performed for the same pathological conditions.nnnMATERIALS AND METHODSnWe compared 6 patients undergoing unilateral laparoscopic ureterolysis for extrinsic ureteral obstruction to 7 undergoing open unilateral ureterolysis for similar pathological conditions. Patient demographic, operative, and early and late postoperative data were collected.nnnRESULTSnLaparoscopic ureterolysis was associated with less intraoperative blood loss and need for parenteral pain medications, and significantly shorter hospital stay and convalescence than open surgery. Although there were no intraoperative or postoperative complications in the laparoscopy group, 1 patient in the open surgery group had an intraoperative ureteral avulsion and 4 had minor postoperative complications (blood transfusion, ileus and/or wound cellulitis). Operative time was longer in the laparoscopy group (255 versus 232 minutes). Subjective followup with an analog pain scale and/or telephone interview showed improvement in all patients in the laparoscopy group and all 6 contacted in the open surgery group. Likewise, excretory urography and/or renal scan showed improved renal function and relief of obstruction in all patients.nnnCONCLUSIONSnLaparoscopic unilateral ureterolysis for extrinsic ureteral obstruction is a less morbid, yet equally effective procedure with several clinical advantages over conventional open surgical ureterolysis.

Impact of ischemia on renal function after laparoscopic partial nephrectomy: a multicenter study.

PURPOSEnWe assessed the influence of renal ischemia on long-term global renal function after laparoscopic partial nephrectomy in patients with 2 functioning kidneys in a large, multicenter cohort.nnnMATERIALS AND METHODSnCollected data included demographic, clinical and surgical characteristics, tumor parameters and renal function outcomes at 4 institutions in a total of 401 patients with 2 functioning kidneys who underwent laparoscopic partial nephrectomy. Renal function was assessed in the immediate postoperative period (days 1 to 3) and at last followup (greater than 1 month) using the estimated glomerular filtration rate calculated by the 4-variable Modification of Diet in Renal Disease equation. Ischemia time and covariates were modeled on the percent change in the estimated glomerular filtration rate using linear regression.nnnRESULTSnMedian ischemia time was 29 minutes (IQR 22, 34). The postoperative change and the last (long-term) change in the estimated glomerular filtration rate were -16% and -11%, respectively. Median time to the last estimated glomerular filtration rate measurement was 13 months (IQR 6, 24). On multivariate analysis shorter ischemia and operative times, external or ureteral irrigation with cold saline and female gender were associated with less postoperative percent change in the estimated glomerular filtration rate. Smaller tumor size and absent diabetes were associated with less of a final percent change in the estimated glomerular filtration rate. Ischemia time was not associated with a percent change in the estimated glomerular filtration rate at last followup.nnnCONCLUSIONSnWithin the range of times in these series renal ischemia did not have a clinically significant impact on global renal function in patients with 2 functioning kidneys who underwent laparoscopic partial nephrectomy, as measured by the estimated glomerular filtration rate.

Subcutaneous urinary diversion utilizing a nephrovesical stent: A superior alternative to long-term external drainage?

OBJECTIVESnThe use of external percutaneous nephrostomy drainage in patients with end-stage ureteral obstruction in whom ureteral stenting has failed presents significant compromises in the patients quality of life. Toward this end, we present the initial experience in the United States with an intracorporeal nephrovesical stent.nnnMETHODSnWe performed successful subcutaneous urinary diversion in 2 patients with malignant, metastatic periureteral obstruction. Both patients had previously been managed with a chronic percutaneous nephrostomy that was both painful and inconvenient. The nephrovesical stent was inserted utilizing percutaneous access to both the kidney and bladder followed by creation of a subcutaneous tunnel between the two sites.nnnRESULTSnThe nephrovesical stents are patent at 6 and 9 weeks postoperatively and both patients have had their nephrostomy tubes removed. Both patients have noted a marked improvement in their overall comfort and quality of life since the stent has been in place.nnnCONCLUSIONSnSubcutaneous urinary diversion with a nephrovesical stent provides effective urinary drainage and may improve the quality of life of patients with malignant metastatic ureteral obstruction. Further long-term studies are needed.

Ureteral Cell Cultures II: Collagen Production and Response to Pharmacologic Agents

PURPOSEnTo investigate the in vitro response of ureteral cells to potentially anti-fibrotic agents.nnnMATERIALS AND METHODSnCultured human uroepithelial cells, smooth muscle cells, and myofibroblasts were assayed for proliferation and production of collagen types I and III, with and without the presence of hydrocortisone, colchicine, retinol, verapamil, and D-penicillamine.nnnRESULTSnHydrocortisone stimulated the proliferation of all three cell types and reduced the type I and type III collagen production by myofibroblasts and smooth muscle cells, respectively. Verapamil enhanced the growth of uroepithelial cells and decreased collagen III production by both uroepithelial and smooth muscle cells. D-penicillamine increased the proliferation of uroepithelial and smooth muscle cells, and inhibited collagen type III production by all three cell types.nnnCONCLUSIONSnIn vitro evidence suggests that hydrocortisone, verapamil, and D-penicillamine have effects that could favorably alter the healing of endoscopic ureteral incisions.

Carbon Dioxide and Helium Insufflation During Laparoscopic Radical Nephrectomy in a Patient With Severe Pulmonary Disease

Carbon dioxide pneumoperitoneum produces variable degrees of hypercapnia. Excessive hypercapnia may result in cardiovascular depression and even cardiac arrest. We report on a woman with marked chronic obstructive pulmonary disease in whom significant hypercapnia and respiratory acidosis developed during laparoscopy with carbon dioxide insuflation, which was reversed when carbon dioxide was replaced with helium. CASE REPORT

Immediate Unplanned Hospital Admission After Outpatient Ureteroscopy for Stone Disease

PURPOSEnMedicare recently changed reimbursement for ureteroscopy, encouraging migration to ambulatory surgical centers. To our knowledge the risk of immediate unplanned hospital admission, which may discourage ureteroscopy at ambulatory surgical centers, is unknown. We determined the rate of immediate unplanned hospital admission, identified factors associated with admission and developed a risk stratification tool to assist with location selection for outpatient ureteroscopy.nnnMATERIALS AND METHODSnWe retrospectively reviewed the records of 1,798 consecutive outpatient ureteroscopic procedures for urolithiasis performed from 1998 to 2008 at our institution. Patients requiring immediate hospital admission were matched 1 to 3 by provider, gender and date with controls who did not require admission. Patient demographics, comorbid conditions, stone history and burden, and operative technique were assessed for impact on admission by bivariate and multivariate logistic regression. A scoring system was developed and estimated admission rates were calculated.nnnRESULTSnThere were 70 immediate unplanned admissions (3.9%). Based on multivariate analysis the factors associated with unplanned admission were any previous admission related to stones (p <0.001), history of psychiatric illness (p = 0.016) and bilateral procedure (p = 0.019). Patients with distal ureteral stones were less likely to require admission (p = 0.026). One point was added for each positive factor and 1 was subtracted for a distal ureteral stone. A risk factor score of 2 or greater in 9% of the cohort was associated with an estimated 20.0% admission rate while lower scores in 91% of the cohort were associated with a 2.9% admission rate.nnnCONCLUSIONSnReadily identifiable factors can stratify the risk of unplanned hospital admission and help guide the selection of the most appropriate facility for outpatient ureteroscopy.

Ureteral cell cultures. I. Characterization and cellular interactions

PURPOSEnTo further understand the biology of ureteral cells, we studied the growth characteristics and in vitro cellular interactions of human ureteral uroepithelial cells, smooth muscle cells and myofibroblasts.nnnMATERIALS AND METHODSnThe proliferation, morphology and immunohistochemical characteristics of human ureteral cells grown in vitro were evaluated under varying conditions.nnnRESULTSnThe growth and morphology of ureteral cells were dependent upon media characteristics, especially the calcium concentration and presence of epidermal growth factor and bovine pituitary extract. Cells demonstrated specific stimulatory interactions via both soluble and insoluble factors. Most important, uroepithelial cells and smooth muscle cells displayed reciprocal enhancement of growth.nnnCONCLUSIONSnThe favorable interactions between ureteral cell types in vitro have implications for future work involving these cells.