Radiofrequency-induced thermal therapy: results of a European multicentre study of resistive ablation of incompetent truncal varicose veins.

OBJECTIVES: To investigate the effectiveness of bipolar radiofrequency-induced thermal therapy (RFITT) in a multicentre non-randomized study. METHODS: Some 672 incompetent saphenous veins (85% great saphenous varicose vein, 15% short saphenous vein) in 462 patients (56.5% CEAP [clinical, aetiological, anatomical and pathological elements] class 3 or worse) were treated in eight European centres. Patients were assessed between 180 and 360 days postoperatively. Occlusion rates were determined by duplex ultrasound and compared with the power used for treatment, pull back rate and experience of the operating surgeon. RESULTS: Complete occlusion rates of 98.4% were achieved when treatments were performed by an experienced operator (more than 20 cases), when the maximum power setting on the RFITT generator was between 18 and 20 W and the applicator was withdrawn at a rate slower than 1.5 second/cm CONCLUSIONS: RFITT is efficacious, well tolerated by patients and has a low incidence of procedure-related post-operative complications.

Percutaneus treatment of varicose veins with bipolar radiofrequency ablation.

UNLABELLED: The traditional surgical treatment of an incompetent great saphenous vein (GSV) and small saphenous vein (SSV) is challenged by endovenous techniques. Bipolar radio frequency induced thermo therapy (RFITT) is a new endovenous treatment, which occludes the vein by using the venous wall as a conductor. Linear endovenous energy density (LEED) describes the amount of energy used for vein closure. MATERIAL/METHODS: From March 2007 till April 2009, two cohorts (23 W and 20 W) were compared, respectively 280 and 178 patients. GSV and SSV were separately analyzed. Follow-up was performed at 3 weeks and 1 year post-operatively with duplex ultrasound, to assess vein closure and perioperative complaints. A visual analog scale (VAS) pain score (range 0-10) was documented. For patients operated after October 2008 follow-up was performed at least 6 months after surgery. RESULTS: 528 GSV and 76 SSV were treated. For the GSV a significant difference in LEED 40.8 17.1 in the 20 W cohort was found, resulting in higher occlusion rates 90.6% compared to 82.7% after 3 weeks. Follow-up of 1 year in the 20 W cohort showed 88.7% occlusion. Multivariate analysis showed that pullback speed (OR 3.7, CI 1.1-12.4) and CEAP classification (OR 3.1, CI 1.7-5.6) were significant predictors for vein occlusion. Despite a higher LEED, post-operative complaints were not significantly worse. CONCLUSION: RFITT is a safe and effective method to treat incompetent saphenous veins. Slower pullback speed with higher LEED results in higher closure rates without causing more pain.

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.

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.

Laparoscopic vascular anastomoses: does robotic (Zeus-Aesop) assistance help to overcome the learning curve?

BACKGROUND: Considerable training is necessary to master laparoscopic suturing and knot-tying. Robotic systems are assumed to facilitate these skills and shorten the learning curve. The effect of laparoscopic experience and robotic assistance on the learning curve of vascular anastomoses was studied. METHODS: A laparoscopically experienced surgeon and a laparoscopically inexperienced surgeon made alternating laparoscopic vascular anastomoses and robot-assisted laparoscopic vascular anastomoses using a Zeus-Aesop surgical robotic system with various prosthetic conduits and suture materials in a laparoscopic training box. RESULTS: Neither laparoscopic method influenced the quality score or leakage rate, but with laparoscopic experience, significantly fewer failures were made. Suturing and knot-tying were faster with laparoscopic experience both with and without the robotic system, and fewer stitch actions and knot actions were performed. The learning curves of both surgeons were not improved by the robotic system. CONCLUSIONS: Experience is the most important factor in the performance of laparoscopic vascular anastomoses. The robotic system was not helpful in shortening the learning curve.

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.

The efficacy of robot-assisted versus conventional laparoscopic vascular anastomoses in an experimental model.

BACKGROUND: Robot-assisted surgery is thought to facilitate complex laparoscopic movements, enhancing advanced laparoscopic procedures. OBJECTIVE: To evaluate the benefit of robotic assistance for laparoscopic vascular surgery. DESIGN: Experimental study using prosthetic conduits in a laparoscopic training box. METHODS: Two surgeons each performed 40 laparoscopic vascular anastomoses alternating with and without robotic assistance. A Zeus-Aesop surgical Robotic system trade mark with 3-D visualisation was used. Each surgeon made 40 anastomoses in total, using different prostheses (5 mm PTFE and 16 mm Dacron) and suture material (Prolene and PTFE). A time-action analysis was performed to evaluate surgical performance. Primary efficacy parameters were quality and leakage of the anastomosis, total time and total number of actions. RESULTS: Equal quality scores and anastomotic leakage were achieved with both techniques. Robotic assistance resulted in significant longer suture and knot tying time and significant more actions were needed compared to the manual laparoscopic procedures. Significant more failures occurred during the robot-assisted procedures. CONCLUSION: In this study, robotic (Zeus-Aesop) assistance did not improve the laparoscopic performance of the surgeon whilst making vascular anastomoses.

Robot-assisted laparoscopic cholecystectomy versus conventional laparoscopic cholecystectomy: a comparative study.

BACKGROUND: The efficacy of conventional laparoscopic cholecystectomy (CLC) was compared with robot-assisted laparoscopic cholecystectomy (RLC). Surgical trainees performed the LC to avoid the surgeon's experience bias. METHODS: Two surgical trainees performed 10 CLCs and 10 RLCs at random with a Zeus-Aesop Surgical Robotic System. The primary efficacy parameters were the total time and the number of actions involved in the procedure. The secondary parameters were setup and dissection times, and the number of grasping and dissection actions. Surgical complications were evaluated. RESULTS: For CLC and RLC, respectively, the total times were 95.4 +/- 28 min and 123.5 +/- 33.3 min and the total actions were 420 +/- 176.3 and 363.5 +/- 158.2. For CLC, the times required for setup (21 +/- 10.4 min) and dissection (50.2 +/- 17.7 min) were less than for RLC (33.8 +/- 11.3 min and 72 +/- 24.3 min, respectively). The numbers of grasping and dissection actions were not significantly different: 41.4 +/- 26.5 and 378 +/- 173.7, respectively, for CLC versus 48.9 +/- 27 and 314.6 +/- 141.9, respectively, for RLC. CONCLUSION: Although feasible, RLC requires significantly more time than CLC because of slower performed actions.

Efficiency of manual versus robotical (Zeus) assisted laparoscopic surgery in the performance of standardized tasks.

BACKGROUND: The objective of this study was to compare the efficiency of manual and robotically assisted laparoscopic surgery. METHODS: To evaluate the surgical efficiency in a set of basic endoscopic movements, 20 medical students without any surgical experience were selected to perform at random a set of laparoscopic tasks either manually or robotic assisted (Zeus). This task consisted of dropping beads into receptacles, running a 25-cm rope, capping a hypodermic needle, suturing, and performing a laparoscopic cholecystectomy on a cadaver liver of a pig. A quantitative time-action analysis was performed to evaluate the efficacy and skill performance in terms of time and the number of actions. RESULTS: The dropping beads exercise and the laparoscopic cholecystectomy required more time when performed with robotic assistance, as compared with manual performance (respectively, median, 78.5 s; range, 63 - 122 s vs median, 144.5 s; range, 100 - 169 s; p <0.01 and median, 34.0 min; range 11-44 min vs median, 46.5 s; range, 21 - 79 min; p = 0.05). A tendency toward fewer total actions in all the robotically assisted exercises was observed. However, significance was shown only in the rope-passing task (median, 71; range, 59 - 87 vs median, 62; range, 57-80; p = 0.05). Grasping the beads, the rope, and either the needle or the cap were tasks that required fewer actions to complete when performed with robotically assistance (respectively, median, 11; range, 10 - 14 vs median, 12.5; range, 11 - 15; p <0.01; median, 56; range, 55 - 60 vs median, 60.5 min; range, 55 - 65; p = 0.03, and median, 6; range, 4 - 21 vs median, 10.5; range, 6 - 38; p = 0.02). As compared with the robotically assisted rope-passing exercise, more failures were made in the manually performed procedure (p = 0.03), mainly caused by unintentional dropping of the rope (p = 0.02). CONCLUSIONS: Robotically assisted laparoscopic surgery by participants without any surgical experience might require more time, but actions can be performed equally or more precisely as compared with manual laparoscopic surgery.

Modulation of T lymphocyte function by neuropeptides. Evidence for their role as local immunoregulatory elements.

In mucosa-bearing organs with inherent lymphoid populations, classical modes for control of the immune response may be augmented by products of extrinsic sensory afferent nerve endings which arborize through the lamina propria compartment containing large numbers of T and B lymphocytes. Therefore, we sought to determine the role of neuropeptides (substance P, vasoactive intestinal peptide, and somatostatin) in immune response regulation by using a homogeneous line of T lymphocytes (AO40.1 hybrid), whose activation is driven by a specific Ag (OVA) and where the end point (IL-2 release) could not be contributed to by accessory or other cells. IL-2 was quantitated by the rate of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) metabolism with the use of a murine CD4+ IL-2-dependent T lymphocyte line, and dose-response effects of each neuropeptide were examined over a broad concentration range (10(-14)-10(-6) M) encompassing that regarded as physiologic. Vasoactive intestinal peptide stimulated IL-2 release at low concentrations with a marked effect at 10(-14) M that gradually returned to control levels by 10(-7) M. Somatostatin was associated with a substantial augmentation of AO40.1 T lymphocyte IL-2 release at 10(-10) to 10(-8) M concentrations, whereas substance P demonstrated a stimulatory effect only at high concentrations (10(-9) to 10(-6) M). Concomitant [3H]thymidine uptake studies suggested that changes in cell proliferation or viability did not account for neuropeptide-induced effects in our system. With several exceptions, similar results were found with mitogen (Con A)-stimulated AO40.1 cells and human colonic lamina propria mononuclear cells. It was concluded that the three study neuropeptides, over a broad range of concentrations, have profound stimulatory (and occasionally inhibitory) effects upon the function of a cloned T lymphocyte hybrid cell responding to specific Ag and that these events may reflect those of Ag-driven mucosal T lymphocytes exposed to neuropeptides in vivo.