Cassio Andreoni

Evaluation of a Vessel Sealing System, Bipolar Electrosurgery, Harmonic Scalpel, Titanium Clips, Endoscopic Gastrointestinal Anastomosis Vascular Staples and Sutures for Arterial and Venous Ligation in a Porcine Model

PURPOSE We assessed the usefulness of the LigaSure (Valleylab, Boulder, Colorado) vessel sealing system for vascular control during laparoscopic surgery and compared it with other available hemostatic modalities. MATERIALS AND METHODS A total of 31 domestic pigs were divided into 5 groups. In groups 1 and 2 the vessel sealing system was compared with titanium clips and Endo-GIA (United States Surgical, Stamford, Connecticut) staples. In group 3 the vessel sealing system was compared with standard Klepinger (Karl Storz, Culver City, California) bipolar forceps. In group 4 the harmonic scalpel and Trimax (United States Surgical) bipolar forceps were compared. In group 5 in vivo laparoscopic application of the vessel sealing system was evaluated. RESULTS The 5 mm. laparoscopic vessel sealing system sealed arteries up to 6 mm. and veins up to 12 mm. in diameter at supraphysiological bursting pressure. We evaluated 13 arteries with a diameter of 6 mm. or less at a mean bursting pressure of 662 mm. Hg (range 363 to 1,985) and 11 veins with a diameter of 12 mm. or less with a mean bursting pressure of 233 mm. Hg (range 63 to 440). Collateral tissue damage extended 1 to 3 mm. from the application site. Standard bipolar energy with Klepinger and Trimax forceps was less reliable and in some cases vessel sealing could not be accurately assessed before vessel division. Collateral tissue injury was 1 to 6 mm. The harmonic scalpel did not reliably seal vessels larger than 3 mm. but resulted in the least acute collateral tissue injury of 0 to 1 mm. CONCLUSIONS In the porcine model the LigaSure system is a viable option for laparoscopic management of arteries up to 6 mm. and veins up to 12 mm. in diameter.

Flexible ureteroscopic lithotripsy: first-line therapy for proximal ureteral and renal calculi in the morbidly obese and superobese patient.

BACKGROUND AND PURPOSE The surgical treatment of kidney and proximal ureteral stones in morbidly obese patients (>14 kg/m2) remains difficult because shockwave lithotripsy is precluded by weight limitations and percutaneous nephrolithotomy is associated with difficult access and a high (9%) rate of transfusion. We review our experience with retrograde ureteroscopic lithotripsy in morbidly obese patients with renal and proximal ureteral stones. PATIENTS AND METHODS Between December 1992 and April 2000, five women and three men with a mean age of 46.5 years (range 33-68 years) and a mean body mass index of 54 (range 45-65.2) underwent 10 independent ureteroscopic procedures for urolithiasis. The average stone size was 11.1 mm (range 5-25 mm). Lithotripsy was performed with the holmium laser in eight patients (60%) the electrohydraulic lithotripter in four (30%), and the tunable-dye laser in the remaining patient. Stone-free status was defined as no stones visible on a plain film with nephrotomograms or CT scan at 3 months. RESULTS The mean operation time was 101 minutes (range 45-160 minutes), and 60% of the procedures were done on an outpatient basis. After the initial procedure, the stone-free rate was 70%. Two patients had fragments <4 mm, and no further therapy was undertaken. There was one complication: transient renal insufficiency (serum creatinine concentration 3.7 mg/dL) secondary to aminoglycoside toxicity. No transfusions were needed. CONCLUSION In the morbidly obese patient with symptomatic stones <1.5 cm, ureteroscopic lithotripsy is safe, successful, and efficient.

Matched pair analysis of shock wave lithotripsy effectiveness for comparison of lithotriptors

PURPOSE In an effort to streamline a comparison of the effectiveness of a new lithotriptor with the standard HM3 lithotriptor (Dornier Medical Systems, Inc., Marietta, Georgia) we used a matched pair analysis design. A matched design often provides more efficient estimates (smaller variances) than an unmatched design given the same sample size. MATERIALS AND METHODS Patients with solitary renal or ureteral calculi treated on a LithoTron shock wave lithotriptor (HealthTronics, Marietta, Georgia) between October 1999 and February 2000 with a minimum followup of 3 months were identified. Evaluable patients treated with the LithoTron were matched using 5 parameters to a data base of patients treated with an unmodified HM3 shock wave lithotriptor between October 1997 and February 2000. Matching criteria consisted of calculus side, calculus location (1 of 7 categories), maximum stone diameter (+/-2 mm.), minimum stone diameter (+/-2 mm.) and patient body mass index (BMI +/-6). When more than 1 match was suitable, matching was directed by random numbers. Following matching, clinical charts and radiographic reports were evaluated for stone clearance and post-shock wave lithotripsy interventions. Stone treatment success was defined as residual fragments less than 2 mm. without need for further intervention. RESULTS A total of 94 potentially evaluable patients treated with the LithoTron were identified and 38 matched pairs were created. Average maximum stone diameter, minimum stone diameter, and BMI were 9.6 and 9.9 mm., 6.7 and 6.8 mm. and 29.3 and 28.9 kg./m. for HM3 and LithoTron cases, respectively. All calculi were radiopaque and consisted of mixed calcium oxalate monohydrate (19 and 13), calcium oxalate dihydrate (1 and 1) or calcium phosphate (2 and 2) in the HM3 and LithoTron groups, respectively. Patients were not specifically matched on stone composition because of incomplete availability. Overall intervention-free, stone treatment success rate was 79% for the HM3 and 58% for the LithoTron. OR for failure of LithoTron versus HM3 treatment was 3.004 (McNemar test p = 0.08). There were 16 discordant pairs. In 4 cases LithoTron was successful and HM3 failed, and in 12 cases LithoTron failed and HM3 was successful. Subgroup analysis revealed a trend for LithoTron treatment failure for lower pole calculi, calculi 10 mm. or greater and BMI of 30 kg./m. or greater. CONCLUSIONS In this initial evaluation the HM3, despite a relatively small study sample size, appeared to provide superior clinical results to the LithoTron (p = 0.08). The use of matched pair analysis using a large cohort of patients treated with the HM3 for retrospective matching may allow for accurate determination of the effectiveness of new lithotripsy technology with a relatively small clinical study group.

Comparison of renal ablation with cryotherapy, dry radiofrequency, and saline augmented radiofrequency in a porcine model.

BACKGROUND Needle ablative therapy has recently generated a lot of interest in the urologic community. We compare renal lesions produced in a porcine model using three forms of needle ablative energy: cryoablation (CR), dry radiofrequency (RF), and saline augmented radiofrequency (SARF). STUDY DESIGN In 10 farm pigs, under ultrasonographic guidance, 40 laparoscopic renal lesions were produced: 825-mm CR lesions were produced with 2.4-mm cryoprobes (Endocare Inc, Irvine, CA), after 1-mL preinfusions of 14.6% saline, 12 SARF lesions were created with 22-gauge needles (2 mL/minute 14.6% saline, 50 W 510 kHz RF for 60 seconds), 12 RF lesions were created with a 2-cm array LeVeen electrode and an RF2000 generator using impedance limited 30 to 60 W double activations (Radiotherapeutics Corp, Mountain View, CA), and 8 RF lesions were produced using 22-gauge needles and double 10 W activations with the RF2000 generator. Eight animals were sacrificed after 1 week for acute pathology. An additional two animals were sacrificed at 8 weeks to provide chronic pathology results for the LeVeen dry RF and SARF modalities. RESULTS CR produced a regular 18- to 22-mm zone of complete necrosis bordered by a 1.5- to 2.5-mm zone of partial necrosis. Acutely, LeVeen RF and single-needle RF produced lesions 25 to 45 mm and 6 to 10 mm wide, respectively. Acutely, SARF produced irregular cone-shaped lesions 15 to 31 mm wide. Only one of eight acute LeVeen RF lesions showed complete necrosis; none of the four 8-week LeVeen RF lesions displayed complete necrosis. Two of the four 8-week SARF lesions displayed complete necrosis. The remainder of the LeVeen RF, single-needle RF, and SARF lesions showed early, indeterminate tubular damage with relative glomerular sparing and bands of complete necrosis (0.5 to 1.5 mm) and inflammation (0.5 to 2 mm) at the periphery. Only CR could be consistently monitored with laparoscopic ultrasonography. CONCLUSIONS Renal cryoablation produces well-defined, completely necrotic lesions that can be monitored reliably with ultrasonography. Longer followup may be required to characterize the full extent of renal necrosis produced by RF, but in the short run, none of the RF modalities reliably produced 100% necrosis in all cases.

Evaluation of the use of a biodegradable ureteral stent after retrograde endopyelotomy in a porcine model.

PURPOSE We evaluated the use of a poly-L-lactide-co-glycolide (PLGA) bioabsorbable ureteral stent after Acucise balloon incision (Applied Medical Resources, Rancho Santa Magarita, California) endopyelotomy in a porcine model. MATERIALS AND METHODS After unilateral Acucise endopyelotomy in 9 female Yucatan minipigs a self-reinforced PLGA stent was placed in 5 (group 1) and a 7Fr double pigtail Percuflex stent (Boston Scientific, Natick, Massachusetts) was placed in 4 (group 2). Preoperatively, and 6 and 12 weeks postoperatively plain x-ray of the kidneys, ureters and bladder, cystography, side specific creatinine clearance and retrograde ureterography were done. The contralateral ureters served as untreated controls. The 7Fr stents were removed at 6 weeks. All animals were sacrificed at 12 weeks after bilateral flow studies. Histological specimens from 4 sites along the urinary tract were graded on a healing score of 0-normal, to 3-severe changes. RESULTS Side specific creatinine clearance was similar to preoperative values at 6 and 12 weeks. At the 2 time points plain x-ray of the kidneys, ureters and bladder in group 1 showed retroperitoneal stent fragments in 3 of the 5 animals, which was confirmed at autopsy. Retrograde ureterography in group 1 showed mild hydronephrosis in all 5 ureters and saccular diverticula in 4, which was similar in 2 and 3 animals, respectively, in group 2. Cystography demonstrated grades 1 to 2 reflux in 2 animals at 6 weeks but none at 12 weeks in group 1 and no reflux at either time point in group 2. Flow rates and healing scores were statistically similar in the 2 groups but the latter trended toward less favorable healing of ureteral musculature with application of the absorbable stent. CONCLUSIONS In this pilot study the use of self-reinforced PLGA biodegradable ureteral stents was feasible after Acucise endopyelotomy in a porcine model with radiographic and fluid flow results that were relatively similar to those of standard 7Fr stents but with less favorable biocompatibility.

LAPAROSCOPIC BILATERAL HAND ASSISTED NEPHRECTOMY FOR AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE: INITIAL EXPERIENCE

PURPOSE The laparoscopic technique for bilateral nephrectomy in patients with autosomal dominant polycystic kidney disease is technically difficult. The procedure may be more acceptable if alterations to the technique made it safer and easier to perform. We describe our initial experience with, and the feasibility and potential benefits of hand assisted laparoscopic nephrectomy for approaching these large kidneys in patients with autosomal dominant polycystic kidney disease. MATERIALS AND METHODS This approach was successfully applied in 3 patients with end stage renal disease due to autosomal dominant polycystic kidney disease. After obtaining transumbilical pneumoperitoneum ports were placed in the umbilicus (12 mm.), sub-xiphoid in the midline (12 mm.) and subcostal in the midclavicular line on each side (12 mm.). The table was tilted 40 degrees away from the planned side of initial nephrectomy with the patient in the half lateral position. A 7 cm. midline incision was made that incorporated the umbilical port and a commercially available hand assistance device was positioned. One surgeon hand was inserted into the abdomen to serve as a retractor/blunt dissector, while the other operated the electrosurgical instruments. The right hand was inserted for left nephrectomy and the left hand was inserted for right nephrectomy. The laparoscope was passed via the sub-xiphoid port and the instruments were placed through the ipsilateral subcostal laparoscopic port. Nephrectomy was completed and the specimen was removed through the hand port incision by draining the cysts as they were exposed to view via the midline incision. When dissection was difficult, an additional port was placed in the anterior axillary line at the umbilical level. Some cysts were ruptured or aspirated to decrease overall kidney size and make extraction possible via the 6 to 7 cm. midline incision. RESULTS All procedures were successfully completed. Mean operative time for bilateral hand assisted laparoscopic nephrectomy was 5.5 hours (range 4.5 to 6.6). Estimated blood loss was 200 cc or less. Patients resumed oral intake on postoperative day 1. The mean amount of parenteral analgesics required postoperatively was decreased. Mean hospital stay was 4.3 days but it was 3 days when considering nephrectomy only. Patients returned to normal activity after an average of 2 weeks. There was sustained resolution of preoperative discomfort based on pain analog scales. At 1 month or less all patients recorded absent pain. They uniformly noticed improved preoperative pulmonary and gastrointestinal symptoms CONCLUSIONS Hand assisted laparoscopic nephrectomy in patients with autosomal dominant polycystic kidney disease makes bilateral nephrectomy a reasonable option. The bilateral procedure may be performed as rapidly as laparoscopic only, unilateral nephrectomy in these cases. The advantages of the hand assisted approach include using tactile sensation to facilitate dissection, rapid blunt finger dissection, hand retraction and the application of immediate tamponade when needed. This procedure provides the benefits of minimal intraoperative blood loss, minimal postoperative pain, brief hospital stay and rapid convalescence in this group of patients at high risk.

Laparoscopic Cyst Decortication in Autosomal Dominant Polycystic Kidney Disease: Impact on Pain, Hypertension, and Renal Function

BACKGROUND AND PURPOSE In patients with autosomal dominant polycystic kidney disease (ADPKD), laparoscopic cyst decortication (LCD) has been proposed as a means to relieve chronic cyst-related pain. We present our 7-year experience with LCD for ADPKD with regard to pain relief, hypertension, and renal function. PATIENTS AND METHODS Between August 1994 and February 2001, 29 ADPKD patients with chronic pain (N=29), hypertension (N=21), and renal insufficiency (N=10) underwent 35 LCD procedures. Every detectable cyst within 2 mm of the renal surface was treated. Pain relief was assessed using a pain analog scale; relative pain relief (RPR) equaled (preoperative pain score) - (postoperative pain score)/(preoperative pain score). Hypertension was evaluated using the antihypertensive therapeutic index (ATI): [(dose of blood pressure medication 1/max dose 1) + (dose med 2/max dose 2) + etc.] x 10. Renal function was assessed using the Cockcroft and Gault formula for creatinine clearance. RESULTS The mean operating room time was 4.9 hours (range 2.6-6.6 hours) with no conversions to open surgery. An average of 220 cysts (range 4-692) were treated per patient. The mean follow-up was 32.3 months (range 6-72 months). The RPR was 58%, 47%, and 63% at 12, 24, and 36 months, respectively. At 12, 24, and 36 months, 73%, 52%, and 81% of patients, respectively, noted >50% improvement in their pain compared with the preoperative situation. Five patients became normotensive, and patients improved their ATI by an average of 49% (range 11%-93%). However, six patients had worsening hypertension, with an ATI increase averaging 53% (range 11%-122%), and one patient who was not hypertensive preoperatively has since developed hypertension. The creatinine clearance changed +4%, +7%, and -2% at 12, 24, and 36 months, respectively. Only one patient had a >20% increase in creatinine clearance. The only patients with a >20% decrease in creatinine clearance were those who had a creatinine clearance <30 mg/dL preoperatively (average decrease 34% [range 20%-51%]). CONCLUSIONS For ADPKD patients with debilitating pain, extensive LCD can provide durable relief. In the majority of patients with pain and hypertension, a marked improvement in blood pressure also occurs. Cyst decortication was not associated with worsening renal function; indeed, renal function remained largely unchanged over the 3-year follow-up period.

Effect of single-dose subarachnoid spinal anesthesia on pain and recovery after unilateral percutaneous nephrolithotomy

PURPOSE We studied the impact of one dose of subarachnoid spinal analgesia on postoperative pain and recovery after percutaneous nephrolithotomy (PCNL). PATIENTS AND METHODS Between August 1999 and May 2000, 20 PCNL patients were randomized into two groups: Group A (N = 9), who received preoperative subarachnoid spinal analgesia with morphine sulfate, and Group B (N = 11), who received no subarachnoid spinal analgesia. Both groups were given general anesthesia, and the nephrostomy site was infiltrated with bupivacaine hydrochloride. Stone size was similar in the two groups, as were ASA classification, age, and body mass index. Pain analog scales (maximum score 10) were completed preoperatively and on the day of surgery (D0), after 1 day (D1), and after 2 days (D2). The amount of morphine sulfate equivalents (MS eq) needed, the activity level, and adverse effects were recorded. RESULTS In Group A, the average pain score on D0, D1, and D2 was 2.7, 3.7, and 1.4, respectively; in Group B, the average pain score was 4, 4.5, and 2, respectively (P > 0.05). The average MS eq used in Groups A and B were 8.3 v 33.8 (P = 0.002) on D0; 17.7 v 28.7 (P > 0.05) on D1; and 11.1 v 10.1 (P > 0.05) on D2. On D0, in Group A, 56% of the patients were ambulating and 11% complained of nausea, while in Group B, 0 were ambulating and 46% complained of nausea. CONCLUSIONS A single preoperative dose of subarachnoid spinal analgesia provides a statistically significant decrease in postoperative parenteral pain medication and earlier ambulation. It also appears to reduce the amount of postoperative pain and decrease nausea.

Cystic phaeochromocytoma is a distinctive subgroup with special clinical, imaging and histological features that might mislead the diagnosis.

To report and analyse cases of cyctic phaeochromocytoma at our institution and in previous publications, as adrenal cystic masses are usually associated with nonfunctional lesions, but they can be phaeochromocytoma.

Laparoscopic renal ablation: an in vitro comparison of currently available electrical tissue morcellators ☆

OBJECTIVES Morcellation with the Cook high-speed electrical laparoscopic (HSEL) morcellator in an impermeable nylon/plastic sack (LapSac) has remained unchanged since its inception nearly one decade ago. Sack deployment and specimen entrapment remain relatively difficult, and morcellation with this device is expensive and relatively slow. As such, in an effort to facilitate specimen entrapment and morcellation, we adapted two currently available electrical morcellators (the Steiner gynecologic morcellator and the electrical prostate morcellator [EPM]) for renal morcellation and compared them with the HSEL morcellator. METHODS All morcellation was performed through a simulated abdominal wall under direct laparoscopic vision. Ten porcine kidneys were ablated with each of the following techniques: HSEL morcellation in a LapSac; HSEL morcellation in a fluid-filled LapSac; Steiner morcellation in an insufflated Endocatch sack; and EPM morcellation in a fluid-filled Endocatch sack. A modified laparoscopic trocar was constructed and used for the Steiner and EPM morcellation. The time to complete morcellation, morcellation product size, and entrapment sack integrity were evaluated for each technique. Cost data for each morcellator are also presented. RESULTS The mean morcellation time for the Steiner, HSEL dry, HSEL wet, and EPM morcellation was 6.0, 15.9, 14.7, and 26.0 minutes, respectively. The mean fragment size for these morcellators was 2.97, 0.65, 0.62, and 0.013 g, respectively. A single entrapment sack perforation was documented in a LapSac during routine HSEL morcellation. CONCLUSIONS Renal morcellation with all three morcellators is feasible. The Steiner morcellator combined with an Endocatch resulted in more rapid morcellation and larger morcellation products.