Port-site recurrence reproduced in the VX-2 rabbit carcinoma model: an in vivo model comparing laparoscopic port sites and open incisions.

BACKGROUND: The use of advanced laparoscopy remains controversial in the field of surgical oncology because the potential for port-site recurrence may violate sound oncologic principles. Two mechanisms are theorized to be the cause of port-site recurrences: first, indirect contamination caused by pneumoperitoneum, aerosolization, or intraperitoneal spread, and second, direct contamination by physical trocar seeding. METHODS: A VX-2 carcinoma cell suspension was transferred under the left renal capsule of 31 rabbits with either an open flank incision (16) or laparoscopy (15). Animals were observed for tumor recurrence at the video port, the working port, and the open incision. Intraoperative findings and necropsy were used to document recurrence. RESULTS: The open incision technique resulted in local tumor recurrence in 1/16 animals with 16/16 viable intraabdominal tumors. The laparoscopic technique resulted in 0/15 video port-site recurrences and 9/15 working port-site recurrences, with 14/15 viable intraabdominal tumors. Recurrence at the laparoscopic working port occurred more frequently than in the open (P < 0.02) or laparoscopic video port groups (P < 0.007). No significant difference existed in recurrence between the open incision and the laparoscopic video port (P > 0.5). CONCLUSIONS: Laparoscopic port-site recurrences can be reproduced using the transplantable VX-2 rabbit carcinoma model. In the VX-2 model, trocar recurrence is the result of direct contamination via surgical instrumentation of viable tumor cells. The effect of the pneumoperitoneum or intraperitoneal cytological spillage (indirect contamination) does not have any effect on trocar recurrence. This model can be used to test and improve laparoscopic techniques to minimize the risk of port-site recurrence. Until technological advances have eliminated the risk of trocar recurrences, direct contact between malignant cells and laparoscopic instruments should be performed with caution.

Treatment of grade 4 renal stab wounds with absorbable fibrin adhesive bandage in a porcine model.

PURPOSE: In a porcine model we evaluated the efficacy of the absorbable fibrin adhesive bandage and other novel fibrin products for treating major renal stab wounds. MATERIALS AND METHODS: In commercial swine we produced an almost lethal, grade 4 renal stab wound via a 3.5 cm. sagittal, centrally located, through-and-through laceration. Each pig then received treatment in random fashion, including conventional oversewing of capsular defects with absorbable gelatin sponge and horizontal mattress sutures in 6, external absorbable fibrin adhesive bandage that was pressure held for 60 seconds in 6, external and internal absorbable fibrin adhesive bandage that was applied externally, inserted into the renal defect and pressure held for 60 seconds in 6, liquid fibrin sealant that was placed in the laceration and held for 60 seconds in 8, fibrin foam that was applied in the same manner as liquid fibrin in 5 and closing of the peritoneum over the lacerated kidney without further treatment in 6. Blood loss and time to hemostasis were recorded. Animals were sacrificed at 6 weeks to evaluate the injured renal unit. RESULTS: Compared with conventional therapy the absorbable fibrin adhesive bandage applied externally alone or externally and internally resulted in significantly less bleeding and significantly less time to hemostasis (p <0.001). Liquid fibrin and fibrin foam did not reliably achieve hemostasis. Postoperatively computerized tomography and histological sectioning suggested that the absorbable fibrin adhesive bandage results in a stable, durable clot and healing is at least as successful as with conventional treatment. CONCLUSIONS: The absorbable fibrin adhesive bandage appears to be a safe, rapid means of renal salvage after injury.

A comparison of radical retropubic with perineal prostatectomy for localized prostate cancer within the Uniformed Services Urology Research Group.

OBJECTIVE: To review and compare the outcome of patients undergoing radical retropubic prostatectomy (RRP) or radical perineal prostatectomy (RPP) for clinically localized prostate cancer. PATIENTS AND METHODS: From 1988 to 1997, 1382 men who were treated by RRP and 316 by RPP were identified from databases of the Uniformed Services Urology Research Group. The following variables were assessed; age, race, prostate-specific antigen (PSA) level before surgery, clinical stage, biopsy Gleason sum, estimated blood loss (EBL), margin-positive rate, pathological stage, biochemical recurrence rate, short and long-term complication rates, impotence and incontinence rates. To eliminate selection bias, the analysis was concentrated on pairs of patients matched by race, preoperative PSA level, clinical stage and biopsy Gleason sum. RESULTS: In the 190 matched patients there were no significant differences between the RRP and RPP groups in either organ-confined (57% vs 55%), margin-positive (39% vs 43%), or biochemical recurrence rates (12.9% vs 17.6% at a mean follow-up of 47.1 vs 42.9 months), respectively. The mean EBL was 1575 mL in the RRP group and 802 mL in the RPP group (P < 0.001). The only significant difference in complication rates was a higher incidence of rectal injury in the RPP group (4.9%) than in the RRP group (none, P < 0.05). CONCLUSIONS: In similar populations of patients, RPP offers equivalent organ-confined, margin-positive and biochemical recurrence rates to RRP, while causing significantly less blood loss.

Potential uses of absorbable fibrin adhesive bandage for genitourinary trauma.

Fibrin sealants have become increasingly popular in nearly all surgical specialties. The absorbable fibrin adhesive bandage (AFAB) is a novel, potentially revolutionary product made from dried fibrinogen and thrombin. The AFAB appears to have excellent efficacy in producing rapid hemostasis in a variety of experimental major renal trauma models. The AFAB also appears to enhance healing of the urinary collecting system. Further study is essential to explore new urologic applications of this exciting technology.

Does the absorbable fibrin adhesive bandage facilitate partial nephrectomy?

PURPOSE: To evaluate the ability of the absorbable fibrin adhesive bandage (AFAB), a prototype product comprising lyophilized fibrinogen and thrombin on a VicrylTM mesh backing, to seal the collecting system and control bleeding after partial nephrectomy. MATERIALS AND METHODS: Growing female pigs (n = 18) underwent left nephrectomy and a 40% (by length) right lower pole partial nephrectomy. One of three treatments was immediately applied: Conventional-closure of the collecting system, ligation of visible segmental vessels, application of SurgicelTM with bolstering sutures to the renal capsule; AFAB-application of up to two 4 x 4-inch AFABs held under pressure for 60 seconds; Placebo-application of a hemostatically inert VicrylTM bandage, visually identical to the AFAB. Blood loss and ischemic and total operative times were recorded, and abdominal computerized tomography (CT) was performed on postoperative day 6. Animals were sacrificed at 6 weeks to evaluate the remaining renal mass histologically. RESULTS: Compared with conventional therapy, use of the AFAB resulted in significantly less bleeding (13 versus 68 ml., p <0.001) and lower operative (7.2 versus 16.3 minutes, p <0.001) and ischemic times (3.4 versus 7.8 minutes, p <0.001). Estimated blood loss in the placebo bandage group was dramatically higher (357 ml., p <0.001). Postoperative CT and histological sectioning suggested that the AFAB produces a stable, durable clot and that healing is at least as successful as with conventional treatment. CONCLUSION: Use of the AFAB facilitated performance of partial nephrectomy by reducing blood loss and ischemic and total operative times. The AFAB appears equivalent to conventional surgery in its ability to seal the collecting system.

Remote operative urology using a surgical telemanipulator system: preliminary observations.

OBJECTIVES: A prototype surgical telemanipulator system was evaluated to determine the feasibility of remotely performing operative urology. METHODS: Surgeons operated remotely on anesthetized swine (n = 4), using a four degree-of-freedom teleoperator system. A stereoscopic video display of the remote surgical field guided tissue manipulation, which was performed using standard instrument tips attached to robotic arms. Nephrectomies, cystotomy closures, and ureteral anastomoses were performed by surgeons linked only by electronic cables to the remote operative field (5 m away). Flexible fiberoptic endoscopy was performed remotely, as well, using a simulated ureter in an ex vivo testing apparatus. The endoscope was positioned and manipulated remotely, and was maneuvered through a 25-cm-long tube. RESULTS: All procedures were completed successfully, demonstrating the capability to remotely incise, dissect, suture, and ligate tissues. Operative times were prolonged; however, the surgical telemanipulator was precise and accurate. Surgeons guided a flexible fiberoptic endoscope by remote observation and manipulation through 5-mm-diameter simulated ureters. There were no operative complications. CONCLUSIONS: Telesurgical manipulation is feasible in a controlled, experimental environment. All critical tasks performed by surgeons can be completed remotely, although performance must be improved substantially before telemanipulators enter the clinical armamentarium. Major hurdles remain in identifying clinical needs, improving performance and safety, and developing telecommunications capabilities that will enable telesurgical systems to achieve regulatory approval and acceptance.

Transfusion of phosphoenolpyruvate-treated blood increases oxygen consumption in acute hemorrhage.

BACKGROUND: Incubating blood with phosphoenolpyruvate decreases hemoglobin oxygen affinity (HOA). This study compared transfusion with phosphoenolpyruvate-treated blood and conventionally stored blood on oxygen consumption in acutely anemic dogs. METHODS: Dogs underwent isovolemic hemodilution (hematocrit = 10%). After 1 hour they were transfused to a hematocrit of 18% with control or phosphoenolpyruvate treated blood. Cardiac output, co-oxymetry, and hemoglobin P50 measurements allowed calculation of oxygen consumption during anemia, and posttransfusion. RESULTS: Hemodilution doubled cardiac output. Transfusion with phosphoenolpyruvate-treated blood allowed greater O2 consumption than control (8.31+/-2.1 and 3.73+/-0.11 cc/kg/mm). There were no differences in arterial or venous PO2 or pH; there were marked differences in HOA, measured by posttransfusion P50 (21+/-3 versus 47+/-4), and mixed venous O2 saturation. CONCLUSIONS: Decreased HOA results in increased O2 consumption in dogs subjected to anemic hypoxia. Phosphoenolpyruvate-treated blood provides increased oxygen consumption at a similar hematocrit when compared with untreated banked blood.

Factors influencing success or failure in the AH-64 course.

A greater percentage of qualified student pilots fail the AH-64 (Apache) transition than any other advanced aircraft transition in the Army. We studied 140 consecutive students presenting for training in an effort to identify factors which might predict success or failure in the AH-64 course. Questionnaires were used to elicit demographic, anxiety level, and motion sickness history information prior to beginning Apache flight training. Motion sickness symptoms (MSS) during the enclosed cockpit, or "bag," phase of training were quantified using pre- and postbag flight symptom questionnaires. Performance measures included grades and flight hours required to pass the course. Only one piece of information obtained prior to flight training was related to performance in the AH-64 course; i.e., students who requested the transition performed measurably better than students who did not. While 7% of pilots described significant MSS on the first day of enclosed cockpit flight, this decreased to 2% by day 5. Severity of symptoms during bag phase was not related to any measure of subsequent performance.

Subjective assessment of contact lens wear by army aircrew.

Because 23% of Army aviators are ametropic, contact lenses have drawn increased attention as a spectacle substitute to solve system compatibility problems. From November 1988 until October 1991, a series of contact lens research protocols were conducted to develop a comprehensive database on contact lens wear in varied environments. Questionnaires were used to assess suitability and acceptability of routine contact lens wear. Responses from 202 subjects were obtained from September 1989 through September 1991. The questions explored operational and safety of flight issues of contact lens wear. Subjects overwhelmingly approved of contact lens use in all settings: 95% expressed greater combat readiness and effectiveness with contact lenses, 98% felt contact lens use (and maintenance) in the cockpit had no adverse impact on safety of flight, and 98% endorsed the routine use of contact lenses. These data highlight Army aircrew acceptance of contact lens use.

Documentation of activity and rest of a U.S. National Guard attack helicopter battalion.

A. U.S. National Guard attack helicopter battalion was monitored in order to document the activity and rest obtained during the annual training exercises. A total of 39 soldiers wore wrist activity monitors during the 2-week training period. The data from these monitors discriminate activity from rest. Results indicated the following: 1) at some point during the exercises, everyone became sleep deprived; 2) the participants who received the most rest of the group were the enlisted headquarters personnel and the pilots; 3) the soldiers who received the least amount of sleep were the commander of the battalion and the maintenance personnel. Some recommendations are offered for future planning of National Guard training exercises.