Robot-assisted laparoscopic surgery of the infrarenal aorta : the early learning curve.

BACKGROUND: Recently introduced robot-assisted laparoscopic surgery (RALS) facilitates endoscopic surgical manipulation and thereby reduces the learning curve for (advanced) laparoscopic surgery. We present our learning curve with RALS for aortobifemoral bypass grafting as a treatment for aortoiliac occlusive disease. METHODS: Between February 2002 and May 2005, 17 patients were treated in our institution with robot-assisted laparoscopic aorto-bifemoral bypasses. Dissection was performed laparoscopically and the robot was used to make the aortic anastomosis. Operative time, clamping time, and anastomosis time, as well as blood loss and hospital stay, were used as parameters to evaluate the results and to compare the first eight (group 1) and the last nine patients (group2). RESULTS: Total median operative, clamping, and anastomosis times were 365 min (range: 225-589 min), 86 min (range: 25-205 min), and 41 min (range: 22-110 min), respectively. Total median blood loss was 1,000 ml (range: 100-5,800 ml). Median hospital stay was 4 days (range: 3-57 days). In this series 16/18 anastomoses were completed with the use of the robotic system. Three patients were converted (two in group 1, one in group 2), and one patient died postoperatively (group 1). Median clamping and anastomosis times were significantly different between groups 1 and 2 (111 min [range: 85-205 min] versus 57.5 min [range: 25-130 min], p < 0.01 and 74 min [range: 40-110 min] versus 36 min [range: 22-69 min], p < 0.01, respectively) Total operative time, blood loss, and hospital stay showed no significant difference between groups 1 and 2. CONCLUSIONS: Robot-assisted aortic anastomosis was shown to have a steep learning curve with considerable reduction of clamping and anastomosis times. However, due to a longer learning curve for laparoscopic dissection of the abdominal aorta, operation times were not significantly shortened. Even with robotic assistance, laparoscopic aortoiliac surgery remains a complex procedure.

The mechanical master-slave manipulator: an instrument improving the performance in standardized tasks for endoscopic surgery.

BACKGROUND: This study aimed to evaluate the feasibility and efficacy of a mechanical minimally invasive manipulator for endoscopic surgery. In contrast to currently available motorized master-slave manipulators, this mechanical manipulator consists of two purely mechanical, hand-controlled endoscopic arms with joints that allow seven degrees of freedom (DOF). METHODS: For the study, 30 medical students performed four different tasks in a pelvic trainer box using either two conventional endoscopic needleholders or a set of mechanical manipulators. The exercise consisted of four different tasks: repositioning of coins, rope passing, passing of a suture through rings, and tying of a surgical knot. All experiments were recorded on videotape (S-VHS), and the data were analyzed afterwards by an independent observer using a quantitative time-action analysis. RESULTS: A significant difference in the number of total actions (including failures) favoring the mechanical manipulator group was shown in most exercises. A significant difference in failures per task was shown in favor of the mechanical manipulator group as well. There was no significant difference shown in the total time per exercise. CONCLUSIONS: The tasks clearly demonstrated the efficacy of the mechanical manipulator, although some technical flaws emerged during the experiments. Considering the fact that a first prototype of the mechanical manipulator was tested, modifications are to be expected in a next model. These experiments show the potential of the mechanical manipulator, and it is expected to be a competitive and economical instrument for endoscopic surgery in the near future.

Laparoscopic vascular surgery: a systematic review.

OBJECTIVE: The objective of this systematic review is to evaluate the results of clinical studies on laparoscopic surgery for aorto-iliac disease. METHODS: A systematic review of the literature from 1966 to September 2006 on laparoscopic and robotic vascular surgery was performed. Only patient series containing more than 5 cases were included. Operative, clamping and anastomosis times, conversion, mortality and morbidity and hospital stay were evaluated. RESULTS: Thirty studies were identified. These were all descriptive and included 9 comparative studies. Operative times varied widely, the shortest being for hand-assisted procedures (2.5-4 hours) and the longest for totally laparoscopic procedures (4-6.5 hours). Clamping times were all<1 hour in hand-assisted procedures while in other techniques clamping times from 1-2.5 hours were seen. The conversion rate varied from <5% up to 16% in smaller series. The mortality rate was approximately 5% and frequently caused by cardiac ischemia. A variety of problems ranging from minor local wound problems to cardiopulmonary- and renal insufficiency, bleeding, ureter lesions and graft thrombosis were described. Mean hospital stay for nearly all procedures was <1 week. CONCLUSIONS: Experience of laparoscopic surgery for aorto-iliac disease is still limited. Most study results are biased by patient selection. Only a few surgeons have mastered the required surgical technique and more data are needed to asses the clinical potential of this type of surgery, in comparison with the endovascular alternative. For wider implementation simplification of the surgical procedure seems necessary.

Preoperative fasting: an outdated concept?

Recent studies have shown that fasting during the preoperative period for elective surgery induces a metabolic state that seems unfavorable for patients. Results from animal studies indicate that rapid depletion of liver glycogen before surgery leads to mobilization of muscle glycogen after surgery, in turn leading to reduced muscle strength. Depletion of liver glycogen also influences the function of the mononuclear phagocytic system (MPS), which is located predominantly in the liver. The MPS is essential in restricting endotoxin, which may translocate from the gut. In addition, surgery per se puts a substantial physical strain on the patient, and fasting may adversely affect the metabolic response to surgery. This paper presents experimental and clinical data that, when combined together, prove that fasting before surgery has adverse consequences for the patient.

Robot-assisted laparoscopic aortobifemoral bypass for aortoiliac occlusive disease: early clinical experience.

BACKGROUND: Robotic technology may facilitate laparoscopic aortic reconstruction. We present our early clinical experience with laparoscopic aortobifemoral bypass, aided by two different robotic surgical systems. METHODS: Between February 2002 and April 2004, we performed eight robot-assisted laparoscopic aorto-bifemoral bypasses for aortoiliac occlusive disease. All patients were male; median age was 55 years (range: 36-64). Dissection was performed laparoscopically and the robotic system was used to construct the aortic anastomosis. RESULTS: A robot-assisted anastomosis was successfully performed in seven patients. Median operative time was 405 min (range: 260-589), with a median clamp-time of 111 min (range: 85-205). Median blood loss was 900 ml (range: 200-5800). Median anastomosis time was 74 min (range 40-110). In two patients conversion was necessary, one due to bleeding of an earlier clipped lumbar artery after completion of the anastomosis, the other because of difficulties with the laparoscopic exposure of the aorta. On post-operative day 3 one patient died unexpectedly as a result of a massive myocardial infarction. Median hospital stay was 7.5 days (range: 3-57). CONCLUSION: Our initial experience with robotic assisted laparoscopic surgery (RALS) shows it is a feasible technique for aortoiliac bypass surgery. However, laparoscopic aortoiliac surgery demands considerable experience and operative times need to be reduced before this technique can be widely implemented.

Aortoiliac steno-occlusion in young women: a single center experience and review of the literature.

Peripheral obliterating arterial disease characterized by aortoiliac steno-occlusion occurring in relatively young women of small stature, is frequently reported in the literature under the name small aorta syndrome. Although it remains unclear whether small aorta syndrome represents a separate entity, the small size of the distal aorta increases risk for aortoiliac occlusive disease. Patients usually present with lower extremity claudication and typical risk factors. This paper shows an analysis of the literature focusing on the pathogenesis, clinical features, risk factors and treatment, as well as a single center experience with this disorder.