Dressing for surgical wounds of the penis.

We describe a simple tubular elastic gauze dressing for surgical wounds of the penis. The amount of pressure placed on the penis is consistent and reproducible. The material is elastic enough to avoid vascular occlusion and is easily applied with a plastic tube. The dressing stays in place, can be used with stents or catheters, and is easily removed by the patients at home.

Pelvic lymphadenectomy can be omitted in selected patients with carcinoma of the prostate: development of a system of patient selection.

OBJECTIVES: The prevalence of pelvic lymph node metastases in men with clinically localized prostate cancer has decreased dramatically over the past decade, possibly due to efforts at early detection. With a significantly lower incidence of pelvic node involvement, it may be possible to identify a segment of patients for whom pelvic lymph node dissection (PLND) may be omitted. This study was conducted to develop a method to select patients for whom PLND could be omitted. METHODS: We analyzed serum prostate-specific antigen (PSA), clinical stage, biopsy Gleason score, and final pathologic stage in 481 men with clinically localized prostate cancer. These variables were compared to the risk of positive pelvic lymph nodes. RESULTS: Logistic regression analysis determined that combining all three variables provided the best determination of final pathologic stage. A series of probability curves have been created to estimate the risk of positive lymph nodes in a given patient. Based on the distribution of patients in this study and using these probability functions, PLND could be avoided in up to 50% of patients with localized prostate cancer diagnosed by contemporary methods. CONCLUSIONS: In properly selected patients, pelvic lymphadenectomy can be omitted in the staging and treatment of localized prostate cancer.

Clinical significance of fever after percutaneous nephrolithotomy.

OBJECTIVES: In the immediate postoperative period after percutaneous stone removal, body temperature elevations are common. Pyrexia after a percutaneous nephrolithotomy (PCNL) generates concern because of the possibility of urinary extravasation and bacteremia. We reviewed our experience with PCNL to determine the clinical significance of a postoperative fever before discharge from the hospital. METHODS: Between July 1994 and December 1996, 63 patients underwent 69 PCNLs. Each had documented negative urine cultures preoperatively and received prophylactic antibiotics at the time of surgery. For each case, clinical and operative charts were reviewed to determine stone composition, fever during hospital stay, postoperative bacteriologic cultures, postoperative white blood cell count (WBC), and clinical course. RESULTS: Complete data were available for 66 procedures. Eight patients (12%) had at least one body temperature reading between 38.0 and 38.5 degrees C. Eleven patients (16.7%) had at least one temperature greater than 38.5 degrees C. Each patient with a temperature greater than 38.5 degrees C was hemodynamically stable with negative blood and urine cultures. No patient with a fever between 38.0 and 38.5 degrees C was cultured. Stone analysis did not demonstrate any association between postoperative fever and stone composition (including 22 struvite stones). Postoperative WBC also did not predict pyrexia. Fever alone did not prolong hospital stay. CONCLUSIONS: In patients with negative urine cultures who are prophylaxed with immediate preoperative antibiotics and maintained on postoperative antibiotics, pyrexia after PCNL does not require an immediate bacteriologic evaluation in those who are hemodynamically stable.

Complete embedding and close step-sectioning of radical prostatectomy specimens both increase detection of extra-prostatic extension, and correlate with increased disease-free survival by stage of prostate cancer patients.

The objectives of this work were to evaluate the efficacy of controlled close step-sectioned and whole-mounted radical prostatectomy specimen processing in prediction of clinical outcome as compared to the traditional processing techniques. Two-hundred and forty nine radical prostatectomy (RP) specimens were whole-mounted and close step-sectioned at caliper-measured 2.2-2.3 mm intervals. A group of 682 radical prostatectomy specimens were partially sampled as control. The RPs were performed during 1993-1999 with a mean follow-up of 29.3 months, pretreatment PSA of 0.1-40, and biopsy Gleason sums of 5-8. Disease-free survival based on biochemical or clinical recurrence and secondary intervention were computed using a Kaplan-Meier analysis. There were no significant differences in age at diagnosis, age at surgery, PSA at diagnosis, or biopsy Gleason between the two groups (P<0.05). Compared with the non-close step-sectioned group, the close step-sectioned group showed higher detection rates of extra-prostatic extension (215 (34.1%) vs, 128 (55.4%), P<0.01), and seminal vesicle invasion (50 (7.6%) vs 35 (14.7%), P<0.01). The close step-sectioned group correlated with greater 3-y disease-free survival in organ-confined (P<0.01) and specimen-confined (P<0.01) cases, over the non-uniform group. The close step-sectioned group showed significantly higher disease-free survival for cases with seminal vesicle invasion (P=0.046). No significant difference in disease-free survival was found for the positive margin group (P=0.39) between the close step-sectioned and non-uniform groups. The close step-sectioned technique correlates with increased disease-free survival rates for organ and specimen confined cases, possibly due to higher detection rates of extra-prostatic extension and seminal vesicle invasion. Close step-sectioning provides better assurance of organ-confined disease, resulting in enhanced prediction of outcome by pathological (TNM) stage.

Laparoscopic retroperitoneal renal biopsy.

Histologic information can be pivotal in making treatment decisions. Ultrasound-guided percutaneous biopsy is the current standard, but if this procedure fails or is considered to be high risk, laparoscopic biopsy may be appropriate. A CT or ultrasound scan is obtained to determine whether there is any condition that would mandate biopsy of a particular kidney. The retroperitoneal space is entered with a visual obturator, and, after CO2 insufflation to 15 to 20 mm Hg, the space is enlarged initially by blunt dissection with the laparoscope. Two-tooth biopsy forceps are used to obtain tissue, and hemostasis is achieved with the argon beam coagulator with care to vent the increased pressure created by the flow of gas. Postoperatively, specific attention is given to blood pressure control. Hemorrhage is the most common serious complication, so any anticoagulation regimen must be reinstituted cautiously.

The broken stone basket: configuration and technique for removal.

PURPOSE: We investigated the ease of breakage of endoscopic stone baskets with the holmium:yttrium-aluminum-garnet (YAG) laser and their resultant configuration. More importantly, possible safe methods of retrieval were evaluated. MATERIALS AND METHODS: Endoscopic stone baskets from Bard (Platinum Class 2.4F Flat and 3.0F Helical Wire), Cook (3.2F Captura, 3.2F Atlas, 3.0F N-Circle, 4.5F N-Force), and Microvasive (2.4F Zero Tip, 3.0F Gemini, 3.0F Segura) were broken once using the holmium:YAG laser. The energy (kJ) required to break one of the wires was recorded. Configuration was documented using photographs. Baskets were disassembled and assessed for extraction through a 7F open-ended catheter, an 8F/10F set, and a 20F peel-away sheath. RESULTS: Tipless baskets (N-Circle, Zero Tip) broke the easiest (range 0.02-0.03 kJ). Tipped baskets (Segura, Platinum Class Flat and Helical, Gemini, Captura, N-Force, Atlas) were more resistant, but all broke within the range (0.06-0.78 kJ) typically used for intracorporeal lithotripsy. Broken segments of wire tended to protrude outward, with tipless baskets having less change in configuration than tipped baskets. Tipless baskets could easily be pulled into any of the extracting devices, whereas tipped baskets could not. CONCLUSIONS: Baskets break at typical holmium:YAG intracorporeal lithotripsy energy settings. Tipless baskets break easiest and assume a safer configuration. Tipless baskets are extracted easily through a 7F open-ended catheter, 8F/10F set, or 20F sheath, while tipped baskets are unable to be extracted through any of these.

Laser lithotripsy and cyanide.

BACKGROUND AND PURPOSE: Holmium:YAG lithotripsy of uric acid calculi produces cyanide. The laser and stone parameters required to produce cyanide are poorly defined. In this study, we tested the hypotheses that cyanide production: (1) varies with holmium:YAG power settings; (2) varies among holmium:YAG, pulsed-dye, and alexandrite lasers; and (3) occurs during holmium:YAG lithotripsy of all purine calculi. MATERIALS AND METHODS: Holmium:YAG lithotripsy of uric acid calculi was done using various optical fiber diameters (272-940 microm) and pulse energies (0.5-1.5 J) for constant irradiation (0.25 kJ). Fragmentation and cyanide were quantified. Cyanide values were divided by fragmentation values, and fragment sizes were characterized. To test the second hypothesis, uric acid calculi were irradiated with Ho:YAG, pulsed-dye, and alexandrite lasers. Fragmentation and cyanide were measured, and cyanide per fragmentation was calculated. Fragment sizes were characterized. Finally, Ho:YAG lithotripsy (0.25 kJ) of purine and nonpurine calculi was done, and cyanide production was measured. RESULTS: Fragmentation increased as pulse energy increased for the 550- and 940-microm optical fibers (P < 0.05). Cyanide increased as pulse energy increased for all optical fibers (P < 0.002). Cyanide per fragmentation increased as pulse energy increased for the 272-microm optical fiber (P = 0.03). Fragment size increased as pulse energy increased for the 272-microm, 550-microm, and 940-microm optical fibers (P < 0.001). The mean cyanide production from 0.25 kJ of optical energy was Ho:YAG laser 106 microg, pulsed-dye 55 microm, and alexandrite 1 microg (P < 0.001). The mean cyanide normalized for fragmentation (microg/mg) was 1.18, 0.85, and 0.02, respectively (P < 0.001). The mean fragment size was 0.6, 1.1, and 1.9 mm, respectively (P < 0.001). After 0.25 kJ, the mean amount of cyanide produced was monosodium urate stones 85 microg, uric acid 78 microg, xanthine 17 microg, ammonium acid urate 16 microg, calcium phosphate 8 microg, cystine 7 microg, and struvite 4 microg (P < 0.001). CONCLUSIONS: Cyanide production varies with Ho:YAG pulse energy. To minimize cyanide and fragment size, Ho:YAG lasertripsy is best done at a pulse energy < or = 1.0 J. Cyanide production from laser lithotripsy of uric acid calculi varies among Ho:YAG, pulsed-dye, and alexandrite lasers and is related to pulse duration. Cyanide is produced by Ho:YAG lasertripsy of all purine calculi.

Utility of the harmonic scalpel for laparoscopic partial nephrectomy.

Laparoscopic partial nephrectomy (LPN) remains a technically challenging procedure largely because of the lack of methods for obtaining consistent parenchymal hemostasis. The objective of this study was to determine if the extent of resection influences the ability of the harmonic scalpel to achieve hemostasis and to define the cases in which the harmonic scalpel is appropriate for LPN. Thirty LPNs were performed in a 25-kg domestic pig model. The blunt blade of the laparoscopic harmonic scalpel (LaparoSonic Coagulating Shears; Ethicon Endo-Surgery, Cincinnati, OH) at power level 5 was used to divide the parenchyma. Control of the renal hilar vessels was not obtained. Three standardized types of resections were performed: I = peripheral wedge biopsy; II = upper- or lower-pole nephrectomy; and III = heminephrectomy. Bleeding was graded on a scale from 0 to 4: 0 = no hemostasis; 1 = steady bleeding; 2 = moderate bleeding; 3 = parenchymal oozing; and 4 = dry. Hemostasis grades of 2 or less were clinically significant bleeding necessitating supplemental coagulation. The mean hemostasis scores showed a significant (P < 0.02) trend toward inadequate hemostasis with increasing extent of resection: 3.3 for Type I, 3.0 for Type II, and 2.4 for Type III. The percent of kidneys with grade 2 bleeding or worse was 9% for Type I surgery, 25% for Type II, and 57% for Type III. Successful hemostasis with the harmonic scalpel correlates with the extent of parenchymal resection in the porcine model. Most wedge excisions can be done with the harmonic scalpel alone, whereas larger resections necessitate supplemental coagulation. On the basis of this study, heminephrectomies with the harmonic scalpel are not recommended because of the high incidence of significant hemorrhage.

Laparoscopic renal cryoablation: acute and long-term clinical, radiographic, and pathologic effects in an animal model and application in a clinical trial.

OBJECTIVES: To evaluate renal cryosurgery by studying the feasibility of laparoscopic delivery and the radiographic characteristics and histopathologic effects in a porcine model using different freeze cycles. On the basis of the results, a clinical trial of laparoscopic cryosurgical ablation in select patients with clinical stage T1 renal tumors was started. MATERIALS AND METHODS: Twelve kidneys from six farm pigs underwent cryosurgery. Each kidney was treated with two freeze cycles to -180 degrees C. Six kidneys were retroperitonealized, and six were not. An abdominal CT scan was performed at various times to evaluate for the presence of urinoma or hematoma and to monitor lesion changes. Organs were harvested at times ranging from 24 hours to 13 weeks. Radiographic and histopathologic changes were recorded for each time period. Eight patients with small (average 2-cm) exophytic renal masses underwent laparoscopic biopsy and cryosurgical ablation using a 3- or 4.8-mm probe (Cryomedical Sciences Inc., Rockville, MD) for one 15-minute or two 5-minute freeze cycles to a temperature of -180 degrees C to extend the ice ball at least 7 mm beyond the tumor margin. RESULTS: Dense adhesions between the bowel and cryoablated renal tissue were encountered in all non-retroperitonealized kidneys, but no fistula formation was present. The retroperitonealized kidneys had minimal adhesion formation. None of the animals developed a urinary fistula. At 24 hours and 1 week, CT scanning demonstrated an enhancement defect corresponding to the region of the ice ball with no urinoma or hematoma. At 13 weeks, only a nonenhancing cortical defect was seen. At immediate harvest, hemorrhage was noted in the area of the ice ball with a sharp demarcation at the edge of the freeze zone. At 1 week, four distinct zones were seen: central necrosis, inflammatory infiltrate, hemorrhage, and fibrosis with regeneration. At 13 weeks, the necrotic tissue had been replaced with a circumscribed area of fibrosis. There were no intraoperative or postoperative complications in the eight patients. The estimated blood loss was 140 mL, and the mean hospital stay was 3.5 days. At a mean clinical follow-up of 7.7 (range 1-18) months and radiographic follow-up of 5 months; there have been no tumor recurrences or significant changes in the serum creatinine concentration. At 24 hours, there was an enhancement defect in the area of the ice ball. The CT images at 13 weeks showed a nonenhancing cortical defect in the area of the ice ball. CONCLUSIONS: Cryosurgery can be readily delivered laparoscopically, creating a discrete lesion at the time of treatment that appears to be consistent over time. In the animal studies, complete tissue necrosis developed in the freeze zone, followed by reabsorption, and by 13 weeks, fibrous tissue had replaced the defect. In the animal and human trials, there were no operative complications, urinomas, hematomas, or bowel or urinary fistulas. Follow-up imaging in human trials revealed a persistent nonenhancing defect in the area of the freeze zone. Long-term clinical follow-up will be necessary to determine the cancer-free survival rate.

Laparoscopic nephron-sparing surgery for solid renal masses using the ultrasonic shears.

OBJECTIVES: To report our experience with laparoscopic nephron-sparing surgery (NSS) for solid renal masses. METHODS: Between August 1998 and December 1999, 15 patients with solid renal masses underwent laparoscopic NSS at our institutions. Seven patients underwent a transperitoneal approach and eight a retroperitoneal approach. The kidneys were fully mobilized to allow inspection of all renal parenchyma. The ultrasonic shears were used to divide the renal parenchyma around the tumor in all cases. Renal surface hemostasis was then accomplished by welding a piece of oxidized regenerated cellulose gauze to the transected renal surface with the argon beam coagulator. Tumors were removed intact and sent for analysis of frozen section margin status. RESULTS: Laparoscopic NSS was successfully completed without complications in all patients. The mean tumor size was 2.3 cm (range 0.8 to 3.5), mean operative time was 170 minutes (range 105 to 240), and mean estimated blood loss was 368 mL (range 75 to 1000). The final pathologic finding was renal cell carcinoma in 12 patients and oncocytoma in 3 patients. All final surgical margins were negative. Patients were hospitalized for a mean of 2.6 days (range 2 to 4). CONCLUSIONS: Laparoscopic NSS for small, solid renal masses can be performed safely with a combination of the ultrasonic shears for renal parenchymal transection and argon beam coagulation and oxidized regenerated cellulose gauze for renal surface hemostasis.

Absent ras gene mutations in human adrenal cortical neoplasms and pheochromocytomas.

A variety of human tumors have been studied for ras mutations to date. However, little is known about the prevalence and significance of ras gene activation in adrenal neoplasms. Recently, a study of 10 primary human pheochromocytomas found no evidence for ras mutations. To our knowledge no survey of ras mutations in adrenocortical neoplasms has been reported. Therefore, we analyzed deoxyribonucleic acid (DNA) from 17 archival tumors (8 adrenocortical carcinomas, 6 pheochromocytomas, 2 adrenal adenomas, 1 aldosteronoma, 2 fresh pheochromocytomas and 1 fresh benign adrenal gland) for activating mutations at the 12, 13 and 61 codons of N-ras, H-ras and K-ras. DNA was extracted from archival tissues using 3 different methods: a simplified boiling method, a proteinase-K-phenol chloroform extraction and a novel heat-stable protease Thermus rt41A technique. The boiling and heat-stable protease methods provided for more consistent polymerase chain reaction amplifications than the more laborious phenol chloroform method. This heat-stable protease Thermus rt41A method had not been reported previously for use in archival DNA extraction. Polymerase chain reaction amplified the ras gene regions of interest, and mutations were screened by mutation-specific oligonucleotide probe hybridization of Southern and slot blots. Polymerase chain reaction-generated mutation-specific positive and negative controls were used in the hybridization protocol. With these controlled conditions no definite mutations were detected at codons 12, 13 or 61 of N, H or K-ras. Ras activation via point mutations at these codons rarely, if ever, occurs in adrenal neoplasms.

Holmium:YAG lithotripsy yields smaller fragments than lithoclast, pulsed dye laser or electrohydraulic lithotripsy.

PURPOSE: The mechanism of lithotripsy differs among electrohydraulic lithotripsy, mechanical lithotripsy, pulsed dye lasers and holmium:YAG lithotripsy. It is postulated that fragment size from each of these lithotrites might also differ. This study tests the hypothesis that holmium:YAG lithotripsy yields the smallest fragments among these lithotrites. MATERIALS AND METHODS: We tested 3F electrohydraulic lithotripsy, 2 mm. mechanical lithotripsy, 320 microns pulsed dye lasers and 365 microns. holmium:YAG fiber on stones composed of calcium hydrogen phosphate dihydrate, calcium oxalate monohydrate, cystine, magnesium ammonium phosphate and uric acid. Fragments were dessicated and sorted by size. Fragment size distribution was compared among lithotrites for each composition. RESULTS: Holmium:YAG fragments were significantly smaller on average than fragments from the other lithotrites for all compositions. There were no holmium:YAG fragments greater than 4 mm., whereas there were for the other lithotrites. Holmium:YAG had significantly greater weight of fragments less than 1 mm. compared to the other lithotrites. CONCLUSIONS: Holmium:YAG yields smaller fragments compared to electrohydraulic lithotripsy, mechanical lithotripsy or pulsed dye lasers. These findings imply that fragments from holmium:YAG lithotripsy are more likely to pass without problem compared to the other lithotrites. Furthermore, the significant difference in fragment size adds evidence that holmium:YAG lithotripsy involves vaporization.

Endovascular gastrointestinal stapler device malfunction during laparoscopic nephrectomy: early recognition and management.

PURPOSE: Controlled ligation and division of the renal hilum are critical steps during any nephrectomy procedure. The use of the endovascular gastrointestinal anastomosis (GIA) stapling device for control of the renal vessels during laparoscopic nephrectomy has become standard practice. However, malfunction can lead to serious consequences which require emergency conversion to an open procedure. We report our experience with GIA malfunction during laparoscopic nephrectomy. MATERIALS AND METHODS: From July 1993 to September 1999, 565 patients underwent laparoscopic nephrectomy at 2 institutions for benign and malignant diseases, and for live renal donation. Retrospective chart reviews and primary surgeon interviews were conducted to determine etiology of failure, intraoperative management and possible future prevention. RESULTS: Malfunction occurred in 10 cases (1.7%). In 8 cases the renal vein was involved and malfunctions affected the renal artery in 2. The estimated blood loss ranged from 200 to 1,200 cc. Open conversions were necessary in 2 cases (20%). The etiology of the failure included primary instrument failure in 3 cases and preventable causes in 7. Open surgery was required in 2 patients and laparoscopic management was possible in 8. CONCLUSIONS: The endovascular GIA stapler is useful in performing laparoscopic nephrectomy. However, malfunctions may occur, and can be associated with significant blood loss and subsequent need for conversion to an open procedure. The majority of errors could be avoided with careful application and recognition. Many failures, especially when recognized before release of the device, can be managed without conversion to an open procedure.

Fibrin sealant treatment of splenic injury during open and laparoscopic left radical nephrectomy.

PURPOSE: We describe the use of fibrin sealant for rapid and definitive hemostasis of splenic injuries incurred during open and laparoscopic left nephrectomy. MATERIALS AND METHODS: In 2 patients undergoing left nephrectomy for a suspicious renal mass splenic laceration occurred during mobilization of the colonic splenic flexure at open nephrectomy and laparoscopic upper pole dissection, respectively. Fibrin sealant was applied topically in each case. RESULTS: In each patient fibrin sealant achieved immediate hemostasis and each recovered without further splenic bleeding. CONCLUSIONS: The topical application of fibrin sealant safely, rapidly and reliably achieves definitive hemostasis of splenic injuries. It is simple to use in the open and laparoscopic approaches.

Laparoscopic bowel injury: incidence and clinical presentation.

PURPOSE: Bowel injury is a potential complication of any abdominal or retroperitoneal surgical procedure. We determine the incidence and assess the sequelae of laparoscopic bowel injury, and identify signs and symptoms of an unrecognized injury. MATERIALS AND METHODS: Between July 1991 and June 1998 laparoscopic urological procedures were performed in 915 patients, of whom 8 had intraoperative bowel perforation or abrasion injuries. In addition, 2 cases of unrecognized bowel perforation referred from elsewhere were reviewed. A survey of the surgical and gynecological literature revealed 266 laparoscopic bowel perforation injuries in 205,969 laparoscopic cases. RESULTS: In our series laparoscopic bowel perforation occurred in 0.2% of cases (2) and bowel abrasion occurred in 0.6% (6). The 6 bowel abrasion injuries were recognized intraoperatively and 5 were repaired immediately. In 4 cases, including 2 referred from elsewhere, perforation injuries were not recognized intraoperatively and they had an unusual presentation postoperatively. These patients had severe, single trocar site pain, abdominal distention, diarrhea and leukopenia followed by acute cardiopulmonary collapse secondary to sepsis within 96 hours of surgery. The combined incidence of bowel complications in the literature was 1.3/1,000 cases. Most injuries (69%) were not recognized at surgery. Of the injuries 58% were of small bowel, 32% were of colon and 50% were caused by electrocautery. Of the patients 80% required laparotomy to repair the bowel injuries. CONCLUSIONS: Bowel injury following laparoscopic surgery is a rare complication that may have an unusual presentation and devastating sequelae. Any bowel injury, including serosal abrasions, should be treated at the time of recognition. Persistent focal pain in a trocar site with abdominal distention, diarrhea and leukopenia may be the first presenting signs and symptoms of an unrecognized laparoscopic bowel injury.

The "mini-perc" technique: a less invasive alternative to percutaneous nephrolithotomy.

The disadvantages of standard percutaneous nephrolithotomy (PCNL) as compared with ureteroscopy or extracorporeal shock-wave lithotripsy include increased blood loss, greater pain, and longer hospital stay. A 13-Fr "mini-perc" technique using a ureteroscopy sheath for PCNL was developed in an attempt to address these drawbacks. Nine "mini-percs" have been performed in patients aged 40-73 years with stone burdens of < or = 2 cm2. On average, patients had 1.4 stones with a cross-sectional area of 1.5 cm2. The mean total procedure time, estimated blood loss, and hematocrit decrease were 176 min, 83 ml, and 6.6%, respectively. On average, patients used 14 mg of parenteral morphine and stayed 1.7 days in the hospital. There was no procedure-related complication or transfusion. Eight of nine kidneys (89%) were stone-free on early follow-up at a mean of 3.8 weeks. As compared with standard PCNL, the "mini-perc" technique has similar early success rates in selected patients and may offer advantages with respect to hemorrhage, postoperative pain, and shortened hospital stays.

Remote percutaneous renal access using a new automated telesurgical robotic system.

Previous clinical application of remote telesurgery has been the use of a novel system of video teleconferencing equipment along with remote control of a laparoscopic camera at distances over 11,000 miles. Recently, a robotic system has been developed to assist with percutaneous renal surgery. This robot has been incorporated into the telesurgical system to allow remote needle placement into the renal collecting system under radiological guidance. The main component of the telesurgical system is a low degree of freedom robot called "PAKY" (percutaneous access of the kidney). It is custom designed for fluoroscopic guided percutaneous needle insertion into the renal collecting system. The robot is a six-degrees of freedom device. However, when the skin entry site is fixed and held in position, only two degrees of freedom are required to orient the needle in the correct plane for accurate insertion. Remote control of the robot was accomplished over a plain old telephone system (POTS) line. On June 17, 1998, the first remote telerobotic percutaneous renal access procedure was performed between the Johns Hopkins Hospital, Baltimore, Maryland, and Tor Vergata University, Rome, Italy. This new telesurgical robot was successful in term of obtaining percutaneous access within 20 min, with two attempts to obtain entry into the collecting system. This robot represents the first system for performing remote telesurgical interventions in the kidney and demonstrates the feasibility and safety of assisting accurate and rapid needle access to the kidney during percutaneous procedures.

Laparoscopic and computed tomography-guided percutaneous radiofrequency ablation of renal tissue: acute and chronic effects in an animal model.

OBJECTIVES: To evaluate the laparoscopic and percutaneous delivery of impedance-based radiofrequency ablation (RFA) of the kidney by studying the acute and chronic clinical, radiographic, and histopathologic effects in the porcine model. METHODS: Eight kidneys from 4 pigs underwent laparoscopic RFA. Six kidneys from 3 additional pigs received computed tomography (CT)-guided, percutaneous RFA. CT scans were performed immediately after RFA and before harvest at 2 hours, 24 hours, 3 weeks, and 13 weeks. The gross, radiographic, and histopathologic changes were recorded for each period. RESULTS: Grossly, the RFA lesions were sharply demarcated, measuring 3 to 5 cm. Two major complications (14%) occurred (one urinoma, one psoas muscle injury) in 14 ablations. No deaths or significant blood loss occurred as a result of RFA. Radiographically, the immediate CT scanning demonstrated small perinephric hematomas and wedge-shaped defects. Delayed CT showed nonenhancing defects up to 5 cm. Color-flow and power Doppler were unable to distinguish significant tissue changes during RFA. The histopathologic evaluation revealed marked inflammation surrounding the necrotic regions in the early lesions; chronic lesions were characterized by dense fibrosis. The tissue temperatures ranged from 62 degrees to 118 degrees C in the area of ablation. CONCLUSIONS: RFA is readily delivered laparoscopically or percutaneously with minimal morbidity. Impedance-based application of radiofrequency energy allows monitoring and control of ablation. Using a multi-antenna probe, areas of tissue up to 5 cm can be completely destroyed. The RFA lesion can be monitored as a nonenhancing cortical defect on CT.

Laparoscopic versus open pyeloplasty: assessment of objective and subjective outcome.

PURPOSE: We determine the subjective and objective durability of laparoscopic versus open pyeloplasty. MATERIALS AND METHODS: From August 1993 to April 1997, 42 patients underwent laparoscopic pyeloplasty (laparoscopy group) with a minimum clinical followup of 12 months (mean 22). Subjective outcomes and objective findings were compared to those of 35 patients who underwent open pyeloplasty (open surgery group) from August 1986 to April 1997 with a minimum clinical followup of 12 months (mean 58). We assessed clinical outcome based on responses to a subjective analog pain and activity scale. In addition, radiographic outcome was assessed based on the results of the most recent radiographic study. RESULTS: Of the 42 laparoscopy group patients 90% (38) were pain-free (26, 62%) or had significant improvement in flank pain (12, 29%) after surgery. Two patients had only minor improvement and 2 had no improvement in pain. Surgery failed in only 1 patient with complete obstruction. A patent ureteropelvic junction was demonstrated in 98% (41 of 42 patients) of the laparoscopy group on the most recent radiographic study (mean radiographic followup 15 months). Of the 35 open surgery group patients 91% were pain-free (21, 60%) or significantly improved (11, 31%) after surgery. One patient had only minor improvement and 2 were worse. CONCLUSIONS: Pain relief, improved activity level and relief of obstruction outcomes are equivalent for laparoscopic and open pyeloplasty.