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Biomedical subjects

L R Kavoussi

Publications and source records attributed to L R Kavoussi.

At least 55 records · Page 3Linked to original sources
PubMed2000

Laparoscopic live donor nephrectomy: pre-operative assessment of technical difficulty.

Laparoscopic live donor nephrectomy decreases disincentives to live kidney donation. Thus, many centers are interested in adopting this procedure. However, the high stakes involved for both the donor and the recipient, and the technical difficulties of the operation, have tempered the enthusiasm of some surgeons. Ideally, if early in their series, surgeons could select patients that would be the least challenging technically, it would facilitate the dissemination of this operation. The purpose of this study is to determine if anatomic or radiologic parameters can accurately assess pre-operatively the degree of technical difficulty of laparoscopic live donor nephrectomy for any individual patient. Abdominal spiral three-dimensional CT scanning was performed prior to laparoscopic donor nephrectomy. CT scans were reviewed for six radiographic anatomic parameters. Seven clinical anatomic measurements relating to body habitus were recorded upon induction anesthesia at the time of surgery. Demographic data for gender, age, race, weight, height, and smoking history were collected. Following laparoscopic live donor nephrectomy, the following six component parts of the operation were graded on a scale of 1-4 (1 = easy, 4 = very difficult) for technical difficulty: a) mobilization of the colon; b) mobilization of the upper pole; c) dissection of the renal vein; d) dissection of the renal artery; e) division of the adrenal vein; and f) dissection of the ureter. Also, operative time, estimated blood loss, and intra-operative fluid requirements were recorded as surrogate markers of operative difficulty. Forty-one patients were included in the study. Laparoscopic donor nephrectomy was successfully completed in all cases. The sum of the difficulty scores was 9.9+/-3.1 (mean) (range, 6-18). No anatomic, demographic, or radiologic parameters were predictive of the total operative difficulty score. Of the surrogate markers, only operative time correlated with total difficulty score (R = 0.47, p = 0.003). Donor weight and abdominal girth correlated with operative time (R = 0.50, p = 0.002; R = 0.38, p = 0.019) but not with total difficulty score (R = 0.10, p = 0.51; R = -0.02, p = 0.90, respectively). When the easiest cases and the hardest cases (< or = 25th percentile and > or =75th percentile total difficulty score, respectively) were segregated out, again no anatomic, demographic, or radiologic parameters were predictive of operative technical difficulty. In conclusion, laparoscopic live donor nephrectomy technical difficulty could not be predicted by body habitus from the variables examined in this study. Hence, it was equally likely that performing laparoscopic live donor nephrectomy using a heavy donor would be technically easy, as using a thin donor would be difficult. Although, in general, operative time increased with donor size and weight, it appears that laparoscopic live donor nephrectomy operative technical difficulty is dependent upon such factors as amount of laparoscopic working space, quality of tissue planes, and retractability of the colon and mesocolon; factors that, to date, are not quantifiable.

Adult↗
PubMed2000

Feasibility of ablating normal renal parenchyma by interstitial photon radiation energy: study in a canine model.

BACKGROUND AND PURPOSE: A miniature photon radiosurgery system (PRS) has been described as an alternative to surgical resection and external-beam radiation for tumors and may now offer an alternative for ablation of renal lesions. We evaluated the feasibility of ablation by PRS in a normal parenchyma canine model. MATERIALS AND METHODS: Twelve mongrel dogs were used in this survival study. In the left and right kidneys of each animal, a peripheral lesion and central-hilar lesion, respectively, were induced with PRS. The probes were placed in the renal parenchyma, and local radiation of 15 Gy at a radius of 1.3 cm was delivered over 10 minutes. Serum electrolytes were measured serially. Computed tomography scans were obtained, and the animals were sacrificed for pathologic correlation. In a separate study, the liver received three additional treatments of 10 to 20 minutes of radiation. RESULTS: Eleven dogs survived this 6-month study and were sacrificed as scheduled. One animal expired after 2 weeks from radiation-induced fulminant hepatic failure with normal renal function. No other complications were observed. The average lesion size was 2.5 cm in diameter. Histologic analysis confirmed coagulative necrosis with sharp demarcation from the surrounding parenchyma. CONCLUSION: Preliminary studies demonstrate the feasibility of PRS ablation of the renal parenchyma. Further tumor model testing will be important to determine the ultimate efficacy of local photon radiation energy.

Animals↗
PubMed2000

Effect of time delay on surgical performance during telesurgical manipulation.

BACKGROUND: Telementoring allows a less experienced surgeon to benefit from an expert surgical consultation, reducing cost, travel, and the learning curve associated with new procedures. However, there are several technical limitations that affect practical applications. One potentially serious problem is the time delay that occurs any time data are transferred across long distances. To date, the effect of time delay on surgical performance has not been studied. MATERIALS AND METHODS: A two-phase trial was designed to examine the effect of time delay on surgical performance. In the first phase, a series of tasks was performed, and the numbers of robotic movements required for completion was counted. Programmed incremental time delays were made in audiovisual acquisition and robotic controls. The number of errors made while performing each task at various time delay intervals was noted. In the second phase, a remote surgeon in Baltimore performed the tasks 9000 miles away in Singapore. The number of errors made was recorded. RESULTS: As the time delay increased, the number of operator errors increased. The accuracy needed to perform remote robotic procedures was diminished as the time delay increased. A learning curve did exist for each task, but as the time delay interval increased, it took longer to complete the task. CONCLUSIONS: Time delay does affect surgical performance. There is an acceptable delay of <700 msec in which surgeons can compensate for this phenomenon. Clinical studies will be needed to evaluate the true impact of time delay.

Evaluation Studies as Topic↗
PubMed2000

Feasibility of telementoring between Baltimore (USA) and Rome (Italy): the first five cases.

BACKGROUND AND PURPOSE: Telemedicine is the use of telecommunication technology to deliver healthcare. Telementoring has been developed to allow a surgeon at a remote site to offer guidance and assistance to a less-experienced surgeon. We report on our experience during laparoscopic urologic procedures with mentoring between Rome, Italy, and Baltimore, USA. MATERIAL AND METHODS: Over a period of 3 months, two laparoscopic left spermatic vein ligations, one retroperitoneal renal biopsy, one laparoscopic nephrectomy, and one percutaneous access to the kidney were telementored. Transperitoneal laparoscopic cases were performed with the use of AESOP, a robotic for remote manipulation of the endoscopic camera. A second robot, PAKY, was used to perform radiologically guided needle orientation and insertion for percutaneous renal access. In addition to controlling the robotic devices, the system provided real-time video display for either the laparoscope or an externally mounted camera located in the operating room, full duplex audio, telestration over live video, and access to electrocautery for tissue cutting or hemostasis. RESULTS: All procedures were accomplished with an uneventful postoperative course. One technical failure occurred because the robotic device was not properly positioned on the operating table. The round-trip delay of image transmission was less than 1 second. CONCLUSION: International telementoring is a feasible technique that can enhance surgeon education and decrease the likelihood of complications attributable to inexperience with new operative techniques.

Baltimore↗
PubMed2000

Laparoscopic live donor nephrectomy: outcomes equivalent to open surgery.

A shortage of kidney donors has contributed to the interest in laparoscopic live-donor nephrectomy. Three transperitoneal ports are used, as is an AESOP robot. To maintain urine flow, the donor is kept volume expanded during the procedure, and the pneumoperitoneum pressure is minimized. The most critical and hazardous part of the surgery is dissection of the renal artery and vein. Abundant periureteral tissue should be left to protect the blood supply. Harvest of the right kidney is more difficult. Placing the extraction incision in the right upper quadrant and using a Satinsky clamp instead of a stapling device at the origin of the renal vein will provide maximum venous length and help prevent postoperative thrombosis of the allograft. In the first 175 laparoscopic renal harvest procedures at Johns Hopkins, the complication rate was 14%, the rate of open conversion was 2%, and 3% of the patients required transfusions. These rates improved with experience. There was no significant difference in the performance of the allografts or the recovery of the recipients from what is seen after open kidney harvest. Wider acceptance of laparoscopic renal harvest will increase the number of donors and will be helped by development of methods and devices that shorten the learning curve.

Humans↗
PubMed2000

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.

Anastomosis, Surgical↗
PubMed2000

Laparoscopic management of urachal cysts in adulthood.

PURPOSE: Managing persistent and symptomatic urachal anomalies requires wide surgical excision. Such intervention is recommended to prevent symptom recurrence and complications, most notably malignant degeneration. However, traditional open excision is associated with significant morbidity and prolonged convalescence. We report our experience with the laparoscopic excision of urachal remnants as a less morbid, minimally invasive surgical alternative. MATERIALS AND METHODS: Between October 1993 and December 1999, 4 patients with a mean age of 43.3 years who had a symptomatic urachal cyst underwent laparoscopic radical excision of the urachal remnant. Using 2, 10 mm. and 1 or 2, 5 mm. ports the urachus and medial umbilical ligaments were divided at the umbilicus cephalad to the cyst. The specimen, which included the urachus, cyst and medial umbilical ligaments, was then separated from the bladder dome with or without the bladder cuff and removed intact. We reviewed the perioperative records to assess morbidity, recovery and outcome. RESULTS: All 4 procedures were completed successfully. No intraoperative or postoperative complications were reported at a mean followup of 15 months (range 2 to 24). Mean operative time was 180 minutes (range 150 to 210) and average hospital stay was 2.75 days (range 1 to 4). Pathological evaluation confirmed a benign urachal remnant in each case. All patients resumed normal activity within 2 weeks. CONCLUSIONS: To minimize the morbidity of radical excision the laparoscopic management of benign urachal remnants in adulthood is efficacious and our preferred method of management.

Adult↗
PubMed2000

Laparoscopic telesurgery between the United States and Singapore.

INTRODUCTION: Telemedicine is the use of electronic digital signals to transfer information from one site to another. With the advent of a telepresence operative system and development of remote robotic arms to hold and manoeuvre the laparoscope, telemedicine is finding its role in surgery, especially laparoscopic surgery. CLINICAL FEATURES AND TREATMENT: We report two successful cases of laparoscopic surgery--radical nephrectomy and varicocelectomy for a 3-cm renal tumour and for bilateral varicoceles causing pain, where a less experienced laparoscopic surgeon in Singapore was telementored by an experienced laparoscopic surgeon located remotely in the United States. Both patients recovered uneventfully and returned home on postoperative day 4 and on the day of surgery, respectively. OUTCOME: This study demonstrates that telementored laparoscopic systems are feasible and safe, between countries halfway across the world. CONCLUSIONS: As the Internet expands in utility and the cost of higher bandwidth telecommunication lines decreases, even to remote countries, telementoring systems will become more affordable and may potentially pave the way for advanced surgical and laparoscopic applications and training for the future.

Humans↗
PubMed2000

Laparoscopic donor nephrectomy.

Live donor renal transplantation provides significant advantages when compared with cadaveric renal transplantation. Unfortunately, there are disincentives associated with donation including prolonged hospitalization, significant postoperative pain, and prolonged convalescence. With the advent of laparoscopic donor nephrectomy, there has been an increase in live donation at centers performing the procedure secondary. Incentives provided by laparoscopic donation include a reduction in hospital stay, less postoperative analgesic requirements, and an earlier return to normal daily activities. Most importantly, graft function and survival are equivalent to open live donation. Laparoscopic donor nephrectomy is evolving to become the preferred method of procuring living donor kidneys.

Humans↗
PubMed1999

Measurement of urinary N-acetyl-beta-D-glucosaminidase to assess renal ischemia during laparoscopic operations.

BACKGROUND: Oliguria during laparoscopy is a well-documented phenomenon of unknown etiology. Experimental evidence suggests that renal perfusion is reduced during pneumoperitoneum. N-acetyl-beta-D-glucosaminidase (NAG), which is present in renal tubular cells, is released into the urine in response to tubular insults. In this study, urinary NAG was measured before and after procedures to assess for ischemic renal injury. METHODS: A total of 31 patients underwent laparoscopic procedures while 28 patients had conventional surgery. Urine was obtained first at the time of preoperative Foley catheter placement and later during the recovery room stay. NAG levels were measured and indexed to urinary creatinine. RESULTS: Operative time for the laparoscopy group was 105 min (range, 15-255); for the conventional group, it was 179 min (range, 75-385) (P < 0.05). No differences were noted between pre- and postoperative NAG levels or between the groups. There was no correlation between urinary NAG levels and operative time. CONCLUSION: Pneumoperitoneum is not associated with a change in the urinary concentration of NAG. This finding suggests that there is no significant renal tubular injury associated with laparoscopic surgery.

Acetylglucosaminidase↗
PubMed1999

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.

Humans↗
PubMed1999

Laparoscopic retroperitoneal lymph node dissection for clinical stage I nonseminomatous germ cell testicular tumors.

OBJECTIVES: To assess retrospectively whether laparoscopic retroperitoneal lymph node dissection (RPLND) in patients with clinical Stage I nonseminomatous germ cell testicular tumor (NSGCT) provides useful pathologic staging information on which subsequent management can be based. Approximately 30% of patients with clinical Stage I NSGCT will have pathologic Stage II disease. METHODS: A retrospective review of 29 patients with clinical Stage I NSGCT who underwent transperitoneal laparoscopic RPLND by a single surgeon was performed. Selection criteria included the presence of embryonal carcinoma in the primary tumor or vascular invasion. A modified left (n = 18) or right (n = 11) template was used. RESULTS: Positive retroperitoneal nodes were detected in 12 (41%) of 29 patients. Ten of these patients received immediate adjuvant platinum-based chemotherapy, and 2 patients refused chemotherapy. The nodes were negative in 1 7 (59%) of 29 patients; all but 2 patients (one with recurrence in the chest, the other with biochemical recurrence) have undergone observation. No evidence of disease recurrence has been found in the retroperitoneum of any patient (follow-up range 1 to 65 months). Prospectively, the dissection was limited if grossly positive nodes were encountered; therefore, the total number of nodes removed was significantly different if the nodes were positive or negative (14 +/- 2 and 25 +/- 3, respectively; P <0.004). Two patients required an open conversion because of hemorrhage. Complications included lymphocele (n = 1) and flank compartment syndrome (n = 1). CONCLUSIONS: Laparoscopic RPLND is a feasible, minimally invasive surgical alternative to observation or open RPLND for Stage I NSGCT. Disease outcomes are favorable to date. Longer follow-up in a larger series is necessary to determine therapeutic efficacy.

Adult↗
PubMed1999

Laparoscopic live donor nephrectomy.

Live donor renal transplantation has many advantages including greater graft and patient survival, shorter waiting periods, improved human leukocyte antigen matching, and less cold ischemia. Until recently, disincentives from the operation, such as prolonged hospitalization, postoperative pain, and significant convalescence, have deterred live donor renal transplantation. This article describes the technique of laparoscopic live donor nephrectomy and briefly reports the results. The procedure has resulted in improved postoperative recovery and shorter convalescence, with no effect on recipient renal function.

Humans↗