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Biomedical subjects

L R Kavoussi

Publications and source records attributed to L R Kavoussi.

At least 37 records · Page 2Linked to original sources

Telesurgery. Remote monitoring and assistance during laparoscopy.

In comparison to open surgery, laparoscopy results in less postoperative pain, shorter hospitalization, more rapid return to the work force, a better cosmetic result, and a lower incidence of postoperative intra-abdominal adhesions. These advantages are indisputable when comparing large series for cholecystectomy and smaller series for pelvic lymph node dissection, nephrectomy, and bladder neck suspension in experienced hands. Urologists have an obligation to explore the application of these methods to urologic disease and to adjust the standard of care accordingly. Several barriers to the expansion of urologic laparoscopic surgery exist. The experience in extirpative and reconstructive urologic procedures is limited when compared with the data on cholecystectomy. These procedures are technically complex and demand advanced laparoscopic skills and familiarity with laparoscopic anatomy. The steep learning curve translates into long operative times and an unacceptably high rate of complications for inexperienced laparoscopic surgeons. Most practicing urologists have no formal training in advanced laparoscopy, and no formal credentialing guidelines exist. Telesurgical technology may provide one solution to this problem. Through telesurgical mentoring, less experienced surgeons with basic laparoscopic skills could receive training in advanced techniques from a world expert without the need for travel. These systems could also be used to proctor laparoscopic cases for credentialing purposes and to provide a more uniform standard of care. This review has outlined some of the exciting progress made in the field of telesurgery over the past 10 years and described some of the technical and legal obstacles that remain to be surmounted. During the 1990s, urologists were at the forefront of innovation in remote telepresence surgery. As the scope of minimally invasive urologic surgery expands during the first few decades of the twenty-first century, telesurgical mentoring should have an increasingly important role.

Education, Medical, Continuing↗

Laparoscopic live donor nephrectomy. A review of the first 5 years.

Laparoscopic live donor nephrectomy is technically feasible. The operation has evolved over the last 5 years and is greatly improved compared with the procedure originally described. Advantages to the donor when compared with the standard open operation are decreased postoperative pain, shorter hospitalization, a quicker recuperation, an earlier return to driving, and an earlier return to employment. These improvements have resulted in fewer lost wages and a lower financial burden for donors. Live donor nephrectomy also provides improved cosmetic results. It successfully removes many of the disincentives to live kidney donation and has resulted in an increased willingness of individuals to donate their kidneys. The operative risk seems to be equivalent to that of the open donor operation performed through a flank approach. Although there is no financial advantage of the laparoscopic operation in terms of hospital costs, the increase seen in live donor transplantation may result in long-term cost savings overall. Kidneys procured laparoscopically function well in recipents in the short and long term. There is no increased risk for rejection or technical complications, and the recipent's length of hospitalization is unaffected. The laparoscopic donor operation does not have any apparent deleterious effect on the recipient. The procedure is being adopted rapidly by transplant centers around the world and has been performed at more than 100 centers on five continents. The authors believe that laparoscopic live donor nephrectomy will become the standard of care in the not too distant future.

Humans↗

Laparoscopic radical prostatectomy: is it feasible and reasonable?

Laparoscopic radical prostatectomy is an extremely challenging procedure for even experienced laparoscopic surgeons, and it is not practical to expect most urologists to learn the technique. Nevertheless, it is a feasible procedure and has short-term results comparable with conventional radical prostatectomy. For LRP to be an acceptable and reasonable alternative, the oncologic results must be equivalent to the results of RRP, and significant advantages is morbidity (hospital stay, pain, incontinence, impotence) must be attained; otherwise, the steep learning curve and the additional expense of the procedure make it difficult to justify as an alternative therapeutic modality. Beside a reduction in the transfusion rate, no other significant advantages of LRP over radical prostatectomy have been demonstrated definitively to date. As a result, the role of LRP in the management of prostate cancer remains investigational, and patients should be informed appropriately. The oncologic results and low morbidity of nerve-sparing RRP set a high standard for a laparoscopic technique to equal.

Costs and Cost Analysis↗

Prospective double-blind study of effect of ketorolac administration after laparoscopic urologic surgery.

BACKGROUND AND PURPOSE: To decrease postoperative dependence on narcotics for analgesia, we have evaluated ketorolac as an adjunct to perioperative pain control in patients undergoing laparoscopic urologic surgery. PATIENTS AND METHODS: Sixty-five patients (34 male, 31 female) were randomized to receive either ketorolac tromethamine (15-30 mg IV q 6 h) or placebo prior to laparoscopic surgery. Patient-controlled analgesia in the form of morphine sulfate was provided. Operative factors such as the type of surgery, operative time, and estimated blood loss were recorded. Postoperative factors such as analog pain score (range 0-10), narcotic usage, and length of stay were evaluated. RESULTS: Fifty-five patients completed the study. The average pain score was 2.2 and 4.5 for the ketorolac and placebo groups, respectively (P < 0.005). The mean amounts of total morphine used were 39.2 mg (ketorolac) and 62.5 mg (placebo) (P = 0.077). The length of stay was not significantly different in the ketorolac (2.5 days) and placebo (2.6 days) groups (P = 0.74). Operative times (P = 0.21) and estimated blood loss (P = 0.60) were not significantly different in the two groups. Ketorolac did not adversely affect renal function; serum creatinine changes were not significantly different from those in the patients receiving placebo (P = 0.50). Laparoscopic pyeloplasty necessitated more narcotic analgesia than did other laparoscopic procedures (P = 0.05). CONCLUSION: Ketorolac decreases the subjective perception of pain after laparoscopic urologic surgery. It is suggested that ketorolac administration decreases the amount of narcotic usage as well. Time to resumption of oral intake and length of hospital stay were not influenced by use of ketorolac.

Adult↗

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.

Aged↗

Laparoscopic donor nephrectomy: an update.

Laparoscopic donor nephrectomy was developed primarily to increase the number of kidneys available for donation. Further evidence of the safety and efficacy of laparoscopic donor nephrectomy has been reported in the literature, as have studies on the cost-effectiveness of this procedure and its role in removing disincentives for renal donation. Specific technical modifications have been developed and refined that improve outcomes when performing laparoscopic harvesting of right kidneys. Other technical modifications have been developed for use in obese patients. With the adoption of these modified techniques, equivalent results to open donor nephrectomy have been reported. Recently, a wide range of alternative approaches (hand-assisted, retroperitoneal, and gasless laparoscopy) have been utilized for laparoscopic donor nephrectomy.

Cost-Benefit Analysis↗

Measurement of bio-impedance with a smart needle to confirm percutaneous kidney access.

PURPOSE: The traditional method of percutaneous renal access requires freehand needle placement guided by C-arm fluoroscopy, ultrasonography, or computerized tomography. This approach provides limited objective means for verifying successful access. We developed an impedance based percutaneous Smart Needle system and successfully used it to confirm collecting system access in ex vivo porcine kidneys. MATERIALS AND METHODS: The Smart Needle consists of a modified 18 gauge percutaneous access needle with the inner stylet electrically insulated from the outer sheath. Impedance is measured between the exposed stylet tip and sheath using Model 4275 LCR meter (Hewlett-Packard, Sunnyvale, California). An ex vivo porcine kidney was distended by continuous gravity infusion of 100 cm. water saline from a catheter passed through the parenchyma into the collecting system. The Smart Needle was gradually inserted into the kidney to measure depth precisely using a robotic needle placement system, while impedance was measured continuously. RESULTS: The Smart Needle was inserted 4 times in each of 4 kidneys. When the needle penetrated the distended collecting system in 11 of 16 attempts, a characteristic sharp drop in resistivity was noted from 1.9 to 1.1 ohm m. Entry into the collecting system was confirmed by removing the stylet and observing fluid flow from the sheath. This characteristic impedance change was observed only at successful entry into the collecting system. CONCLUSIONS: A characteristic sharp drop in impedance signifies successful entry into the collecting system. The Smart Needle system may prove useful for percutaneous kidney access.

Animals↗

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.

Adenoma, Oxyphilic↗

Laparoscopic live donor nephrectomy: the recipient.

BACKGROUND: Laparoscopic live donor nephrectomy offers advantages to the donor in terms of decreased pain and shorter recuperation. Heretofore no detailed analysis of the recipient of laparoscopically procured kidneys has been performed. The purpose of this study was to determine whether laparoscopic donor nephrectomy had any deleterious effect on the recipient. METHODS: A retrospective review was conducted of all live donor renal transplantations performed from January 1995 through April 1998. The control group received kidneys procured via a standard flank approach (Open). Rejection was diagnosed histologically. Creatinine clearance was calculated using the Cockroft-Gault formula. RESULTS: A total of 110 patients received kidneys from laparoscopic (Lap) and 48 from open donors. One-year recipient (100% vs. 97.0%) and graft (93.5% vs. 91.1%) survival rates were similar for the Open and Lap groups, respectively. A similar incidence of vascular thrombosis (3.4% vs. 2.1%, P=NS) and ureteral complications (9.1% vs. 6.3%, P=NS) were seen in the Lap and Open groups, respectively. The incidence of acute rejection for the first month was 30.1% for the Lap group and 31.9% for the Open group (P=NS). The rate of decline of serum creatinine level in the early posttransplantation period was initially greater in the Open group, but by postoperative day 4 no significant difference existed. No difference was observed in allograft function long-term. The median length of hospital stay was 7.0 days for both groups. CONCLUSIONS: Laparoscopic live donor nephrectomy does not adversely effect recipient outcome. The previously demonstrated benefits to the donor, and the increased willingness of individuals to undergo live kidney donation, coupled with the acceptable outcomes experienced by recipients of laparoscopically procured kidneys justifies the continued development and adoption of this operation.

Acute Disease↗

Survey of neuromuscular injuries to the patient and surgeon during urologic laparoscopic surgery.

OBJECTIVES: Laparoscopy may be complicated by neuromuscular injuries, both to the patient and to the surgeon. We used a survey to estimate the incidence of these injuries during urologic laparoscopic surgery, to assess risk factors for these injuries, and to determine preventive measures. METHODS: A survey of neuromuscular injuries associated with laparoscopy submitted to 18 institutions in the United States was completed by 18 attending urologists from 15 institutions. RESULTS: From among a total of 1651 procedures, there were 46 neuromuscular injuries in 45 patients (2.7%), including abdominal wall neuralgia (14), extremity sensory deficit (12), extremity motor deficit (8), clinical rhabdomyolysis (6), shoulder contusion (4), and back spasm (2). Neuromuscular injuries were twice as common with upper retroperitoneal as with pelvic laparoscopy (3. 1% versus 1.5%). Among patients with neuromuscular injuries, those with rhabdomyolysis were heavier (means 91 versus 80 kg) and underwent longer procedures (means 379 versus 300 minutes), and those with motor deficits were older (means 51 versus 42 years of age). Of the surgeons, 28% and 17% reported frequent neck and shoulder pain, respectively. CONCLUSIONS: Although not common, neuromuscular injuries during laparoscopy do contribute to morbidity. Abdominal wall neuralgias, injuries to peripheral nerves, and joint or back injuries likely occur no more frequently than during open surgery, but risk of rhabdomyolysis may be increased. Positioning in a partial rather than full flank position may reduce the incidence of some injuries. Measures to reduce neuromuscular strain on the surgeon during laparoscopy should be considered.

Abdominal Muscles↗

Laparoscopic ileal conduit: five-year follow-up.

OBJECTIVES: To report the techniques used for intracorporeal laparoscopic construction of an ileal conduit urinary diversion and long-term patient follow-up after this procedure. METHODS: A 28-year-old man with cerebral palsy, a neurogenic bladder, and voiding dysfunction was referred for definitive management of his urinary tract after several episodes of pyelonephritis. A conduit urinary diversion was performed using a 5-port, transabdominal approach. An appropriate length of ileum was used for diversion, and ureterointestinal anastomoses were performed using a modified Bricker technique. All aspects of the procedure were performed intracorporeally, including isolation of conduit, bowel reanastomosis, ureteral mobilization, and ureterointestinal anastomosis. A 12-mm port site was enlarged and used as the stoma, which was constructed in routine fashion. RESULTS: Five years after surgery, this patient had normal and stable renal function, with a serum creatinine of 0.8 mg/dL. Serial imaging studies continued to reveal prompt and symmetric renal function and no evidence of obstruction or reflux. CONCLUSIONS: Laparoscopic ileal conduit construction is feasible and can provide durable results. Although technically challenging, ongoing technical refinements will make performance of reconstructive laparoscopy more widely applicable. Larger series with substantial follow-up will help illuminate the place of laparoscopic noncontinent urinary diversion in the surgical armamentarium.

Adult↗

Laparoscopic nephrectomy for autotransplantation.

Proximal ureteral injuries often require extensive reconstruction to repair. Management options include nephrectomy, ileal ureter interposition, extensive spiral bladder flaps, or autotransplantation. We report a patient who sustained a proximal ureteral avulsion and underwent a less invasive repair by way of a laparoscopic nephrectomy and subsequent autotransplantation.

Adult↗

Renal ablative cryosurgery in selected patients with peripheral renal masses.

OBJECTIVES: To present the preliminary results of renal ablative cryosurgery in selected patients. METHODS: Seven patients were treated, all of whom had small peripheral tumors and chose not to undergo partial or radical nephrectomy. Four patients underwent a rib-sparing flank incision; the remaining three underwent laparoscopy. All tumors were biopsied before cryoablation. Intraoperative ultrasound was used to monitor the cryolesion. RESULTS: There were no intraoperative complications. The estimated blood loss averaged 111 mL. To date, 6 of the 7 patients have undergone at least one follow-up computed tomography scan (14.2 months average follow-up); all these scans demonstrated partial resolution of the lesion. Clinically, the patients tolerated the procedure without any renal complications or significant changes in creatinine. CONCLUSIONS: This limited clinical trial has demonstrated the feasibility of treating small peripherally located renal tumors with cryosurgery with minimal morbidity and a favorable outcome. Further studies are necessary to determine the long-term efficacy of this treatment modality.

Aged↗

Renal transplantation: laparoscopic live donor nephrectomy.

Laparoscopic nephrectomy is now performed at many centers worldwide. This technique for organ harvesting offers less postoperative pain, quicker convalescence, and an optimal cosmetic result when compared with the traditional open approach. With experience, the laparoscopic technique is accomplished without compromise to donor safety or allograft function, and complications are comparable with the rates in open historic series. Longer operative times and the need for disposable equipment result in greater hospital costs; however, the quicker convalescence permits patients to resume activity sooner, allowing marked cost savings for patients and employers. The laparoscopic technique is associated with a steep learning curve. Launching a successful laparoscopic living donor program requires a dedicated coordinated effort involving physicians, nurses, and hospital administration. The ultimate impact of this technique on the willingness of individuals to donate has not yet been determined.

Humans↗

Focal hepatic ablation using interstitial photon radiation energy.

BACKGROUND: Intratumoral ablative therapy is being used increasingly for the treatment of primary and secondary hepatic malignancies. The interstitial point-source photon radiosurgery system (PRS) is a novel ablative technique that uses radiation therapy similar in dosimetry to interstitial brachytherapy. STUDY DESIGN: To determine the feasibility, toxicity, and local tissue destructive capabilities of the PRS in the liver, preliminary studies in a nontumor-bearing canine model were examined. A 6-month survival study was conducted. Each animal received three radiation treatments, in the right, central, and left hepatic regions. Three low-dose treatments were delivered to each of six animals (group A), generating a 2.0-cm-diameter radiated sphere with a dose of 20 Gy at the lesion edge. Three high-dose treatments were delivered to each of six animals (group B), generating a 3.0-cm-diameter radiated sphere with 20 Gy at the lesion edge. RESULTS: The treatment reproducibly generated sharply demarcated hepatic ablative lesions proportional to the administered dose. Mean lesion diameter at 1 month was 1.6+/-0.2 cm in group A and 3.4+/-1.0 cm in group B. Lesion size was independent of intrahepatic location, including near vascular structures. PRS therapy, when applied to portal structures, resulted in hilar damage. Hilar damage appeared to be associated with arteriolar thrombosis and bile duct injury. Treatment of regions adjacent to large hepatic veins and the IVC was not associated with vessel thrombosis or stricture. CONCLUSIONS: PRS ablation is a generally well-tolerated method that results in consistent, well-demarcated, symmetric lesions of complete necrosis with minimal adjacent parenchymal injury. Application of such an approach for the treatment of liver tumors is promising.

Animals↗