Newly designed retraction devices for intestine control during laparoscopic aortic surgery: a comparative study in an animal model

Stapled Aortic Anastomoses: A Minimally Invasive, Feasible Alternative to Videoscopic Aortic Suturing?

Widespread applications of totally laparoscopic aortic reconstructions have been limited by the long cross-clamp time required to suture the aortic anastomosis despite improvement in instrumentation. The authors' hypothesis was that a “one-step anastomosis concept” using an intraluminal stapler would allow shorter cross-clamp time but similar patency and imperviousness as videoscopic suturing techniques. An intraluminal stapler (Endopath-ILS, Ethicon) with a modified anvil was used to perform videoscopic-assisted thoracic aorta-to-iliac artery bypass with a 21 mm by 8 mm polytetrafluoroethylene (PTFE) graft in 22 sheep through a minimally invasive approach using a 5 cm thoracotomy. The graft-to-iliac artery anastomoses were hand sutured through a flank incision. Twelve sheep were used to establish the technique and 10 subsequent animals constituted the study group. Aortic cross-clamp time, imperviousness, and need for additional sutures were recorded and compared to previously reported data using videoscopic suturing in pigs. Patency was assessed by comparing lower limb arterial pressures. Macroscopic and microscopic examinations of the anastomoses were performed at different time-points within the first 3 months. Videoscopic-assisted stapled anastomoses were also performed on atherosclerotic aortas of 3 human cadavers. Stapled anastomoses between the thoracic aorta and PTFE graft were completed in 8 of 10 animals. Two animals were euthanized after stapler failure and anastomotic bleeding. Sutures to strengthen the anastomosis had to be used in 4 cases. Mean aortic cross-clamp time in 8 successful cases was 4.3 ±2.9 minutes (range 2–11 minutes) and was significantly shorter than clamp time of videoscopic suturing technique (48.7 ±9.4 minutes, p<0.0001). Imperviousness was good or excellent in 4 animals and fair in 4 animals. All anastomoses were patent at the end of the procedure. Examination of the anastomosis of the 2 failed interventions showed medial aortic tear surrounding the anastomosis in 1 case and misfired staples in the other. No graft occlusion was noted during follow-up ranging from 0 to 12 weeks. At the time of harvest, no bleeding was noted after epinephrine and volume infusion to increase mean arterial pressure to 200 mm Hg for 15 minutes. Macroscopic examination of the anastomoses revealed adequate healing with circumferential stapling of the prosthesis to the aortic wall and no stenosis or thrombus except in 1 false aneurysm (1/7, 14%). Surface electron microscopy showed cells coverage of the anastomosis surface. When applied on human cadaver thoracic and abdominal aorta with atherosclerotic changes, clamping times of less than 5 minutes were achieved. However, imperviousness tested with saline was poor. An automatic stapling device allows performance of a graft-to-aorta anastomosis through a minimally invasive approach with shorter clamping time than a videoscopic suturing technique. However, the current technique of aortic stapling is unreliable and further improvements are needed.

Liver retraction system by C3-muco-adhesive polymer films for laparoscopic surgery

BACKGROUND

Conventional laparoscopic instruments used for retraction may cause trauma at the retraction site. Alternative retraction/lifting especially of heavy solid organs such as the liver may be obtained by other means. The present study was designed to explore the use of C3-muco-adhesive polymers (C3-MAPs), which exhibit strong binding to the liver shortly after application to the organ and which retain strong adhesion for sufficient time, to enable sustained retraction during laparoscopic operations.

METHODS AND MATERIALS

C3-muco-adhesive polymers were produced specifically for the study. In an ex vivo experimental set-up, discs of C3-MAPs were placed on the surface of porcine livers for adhesion and retraction studies involving objective measurements by tensiometry.

RESULTS

Experiments were carried out on 14 porcine livers. The force required to detach the C3-MAPs from the liver exceeded 2.0 N 30 s after application. The adhesion force by C3-MAPs files was sufficient to enable sustained retraction force necessary for exposure of the gall bladder, which was achieved by a mean retraction force of 4.85 N (SD = 0.63). This was sustained for a mean of 130 min (range 17.0-240.0). In the adhesion studies, the forces at 30 s required to detach the polymer discs from the liver exceeded 20 N (upper limit of the load cells of the Instron). The duration of the adhesion enabled sustained optimal gall bladder exposure for periods ranging from 17 to 240 min, with a mean of 130 ± 91 min.

CONCLUSIONS

The results of the present study demonstrate that the adhesion and retraction properties of the engineered C3-MAP films are sufficient to enable complete exposure of the gall bladder for a period exceeding 1 h, confirming their potential for atraumatic retraction in laparoscopic and other minimal-access surgical approaches.

Current and future practices in surgical retraction

Retraction of tissues and anatomical structures is an essential component of all forms of surgery. The means by which operative access is gained through retraction are many and diverse. In this article, the various forms of retraction methods currently available are reviewed, with special reference to hand held, self-retaining and compliant techniques. The special challenges posed by laparoscopic surgery are considered and future developments in new retraction techniques are anticipated.

Three trocars laparoscopic abdominal aortic aneurysm repair

Total laparoscopic abdominal aortic aneurysm resection with tube graft interposition was performed in a 53-year-old woman diagnosed with an infrarenal abdominal aortic aneurysm. The operation was accomplished by a method using three trocars. The operation took 240 minutes. Blood loss was 600 mL. No complications occurred in 13 months of postoperative follow-up. These results show that total laparoscopic abdominal aortic aneurysm repair with three trocars is feasible and worthwhile.

Physiologic Responses to Infrarenal Aortic Cross-Clamping during Laparoscopic or Conventional Vascular Surgery in Experimental Animal Model: Comparative Study

The aim of this study was to compare the hemodynamic and ventilatory effects of prolonged infrarenal aortic cross-clamping in pigs undergoing either laparotomy or laparoscopy. 18 pigs were used for this study. Infrarenal aortic crossclamping was performed for 60 minutes in groups I (laparotomy, n = 6) and II (laparoscopy, n = 6). Group III (laparoscopy, n = 6) underwent a 120-minute long pneumoperitoneum in absence of aortic clamping (sham group). Ventilatory and hemodynamic parameters and renal function were serially determined in all groups. A significant decrease in pH and significant increase in PaCO₂ were observed in group II, whereas no changes in these parameters were seen in group I and III. All variables returned to values similar to baseline in groups I and II 60 minutes after declamping. A significant increase in renal resistive index was evidenced during laparoscopy, with significantly higher values seen in Group II. Thus a synergic effect of pneumoperitoneum and aortic cross-clamping was seen in this study. These two factors together cause decreased renal perfusion and acidosis, thus negatively affecting the patient's general state during this type of surgery.

Instrumentation for laparoscopic renal surgery--Padron Endoscopic Exposing Retractor (PEER) and Endoholder: point of technique

During laparoscopic surgery, as in open surgery, exposure is critical. However, this can be difficult during laparoscopy due to limited haptic feedback and the loss of 3-dimensional visualization. Excessive force may be inadvertently applied by assistants when anatomic structures are retracted; similarly, the retractors may be unknowingly moved because the limited field of view with the laparoscope precludes constant visualization of the retracting instrument. To overcome these problems, we have been using a 5- or 10-mm PEER retractor in combination with an articulating arm instrument holder (Endoholder) to aid laparoscopic renal surgery. The adjustable spring-loaded articulating instrument holder (Endoholder) consists of 4 components, including table attachment, a base rod, flexible extension arm, and precision clamp. The clamp accommodates variously sized instruments, and the flexible extension arm rotates 360 degrees to aid in positioning. The instrument holder is clamped to the table via the base rod over a sterile drape. A PEER Retractor, Roto-lok ratchet (5- or 10-mm diameter and 32-cm length) is placed intracorporeally to retract and position the kidney for hilar, upper, and lower pole dissection. The PEER retractor's handle is secured in place using the precision clamp of the instrument holder. The articulating instrument holder and PEER retractor are used for our renal, adrenal, and ureteral laparoscopic procedures. Placement of the retractor through a 5- or 10-mm port and deployment can be done quickly. Adequate and stable positioning of the retractor provides excellent and secure visualization of the operative field. These instruments have been used in more than 200 cases without any complication except 1 minor liver laceration. The articulating instrument holder with the PEER retractor is a very useful aid during laparoscopic renal surgery. This instrument reduces the chances of inadvertent injury to viscera by the assistant while maintaining an excellent anatomic view throughout the procedure. This will have a significant impact on the advancement of laparoscopy and its acceptance by every urologist.

Total Laparoscopic Aortobifemoral Bypass

AIM

To assess the feasibility of aortobifemoral bypass by a laparoscopic approach.

MATERIAL AND METHODS

During November 2002 through July 2003 a total of 21 patients with aorto-iliac occlusive disease underwent total laparoscopic aortobifemoral bypass surgery.

RESULTS

The median operative time was 240 (range 150-420) min with a median aortic cross-clamp time of 60 (30-120) min. Operating time was reduced with experience. The median blood loss was 500 (100-2500) ml. One conversion to open surgery for acute dilation of the small bowel was necessary. Post-operative complications occurred in five patients (coagulation problems, disseminated intravascular coagulation secondary to thrombosis of the left limb, cerebro-vascular accident, dyspnoea, lymph leak) and there was no peri-operative death. Median hospital stay was 7 (5-30) days.

CONCLUSION

Aorto-bifemoral bypass using a total laparoscopic approach can be performed safely. As all new techniques, a learning curve is observed. This new technique should be evaluated in a larger randomised trial to assess its clinical value in comparison to conventional surgery.

Total laparoscopic bypass for aortoiliac occlusive lesions: 93-case experience

OBJECTIVES

We describe our experience with a new technique of total laparoscopic bypass surgery to treat aortoiliac occlusive lesions.

MATERIAL AND METHODS

From November 2000 to December 2003, 93 total laparoscopic bypass procedures were performed to treat TASC (TransAtlantic Inter-Society Consensus document) grade C or D aortoiliac occlusive lesions. We also reimplanted 2 inferior mesenteric arteries, and performed 3 prosthesis-superior mesenteric bypasses and 2 suprarenal aorta endarterectomies. Our technique includes a sloping right lateral decubitus installation, which enables a simple transperitoneal left retrocolic or retrorenal approach to the infrarenal abdominal aorta. In patients with a hostile abdomen a retroperitoneal videoscopic approach was used. Aorta-prosthesis laparoscopic anastomoses are performed simply, which averts any trauma to the suture material.

RESULTS

Patients included 76 men and 17 women, with median patient age 61 years (range, 38-79 years). The approach to the aorta was always possible, in particular, in obese patients. It enabled stable aortic exposure during performance of the laparoscopic aorta-prosthesis anastomosis. Median operative time was 240 minutes (range, 150-450 minutes). Median aortic clamping time measured to unclamping of the first prosthetic limb was 67.5 minutes (range, 30-135 minutes). Median duration of aorta-prosthesis anastomosis was 30 minutes (range, 12-90 minutes). The longest durations were mainly observed during the learning curve. Thirty-day postoperative mortality was 4% (4 of 93 patients). Two patients died of myocardial infarction. One patient with American Society of Anesthesiologists grade 4 disease operated on to treat critical ischemia died of multiple organ system failure, and 1 patient died of colonic ischemia. Major nonlethal postoperative complications were observed in 4 patients, and included lung atelectasia in 2 patients, graft infection in 1 patient operated on emergently to treat aortic occlusion, and secondary spleen rupture at day 5 in 1 patient. Median hospital stay was 7 days (range, 2-57 days). With a mean follow-up of 19 months (range, 1-37 months), complete recovery was observed in 89 patients, and all grafts were patent. One patient had kinking of a prosthetic limb at the groin, and in 1 patient Staphylococcus epidermidis graft infection developed, which was treated with in situ replacement with a rifampin-bonded graft.

CONCLUSION

Total laparoscopic aortic bypass is feasible. In patients with TASC C and D aortoiliac occlusive lesions, short-term outcomes are comparable to those with conventional aortic bypass. After the initial learning curve, laparoscopic technique may reduce the operative trauma of aortic bypass.

Total laparoscopic infrarenal aortic aneurysm repair: Preliminary results

OBJECTIVES

We describe our initial experience of total laparoscopic abdominal aortic aneurysm (AAA) repair.

MATERIAL AND METHODS

Between February 2002 and September 2003, we performed 30 total laparoscopic AAA repairs in 27 men and 3 women. Median age was 71.5 years (range, 46-85 years). Median aneurysm size was 51.5 mm (range, 30-79 mm). American Society of Anesthesiologists class of patients was II, III and IV in 10, 19, and 1 cases, respectively. We performed total laparoscopic endoaneurysmorrhaphy and aneurysm exclusion in 27 and 3 patients, respectively. We used the laparoscopic transperitoneal left retrocolic approach in 27 patients. We operated on 2 patients via a tranperitoneal left retrorenal approach and 1 patient via a retroperitoneoscopic approach.

RESULTS

We implanted tube grafts and bifurcated grafts in 11 and 19 patients, respectively. Two minilaparotomies were performed. In 1 case, exposure via a retroperitoneal approach was difficult and, in another case, distal aorta was extremely calcified. Median operative time was 290 minutes (range, 160-420 minutes). Median aortic clamping time was 78 minutes (range, 35-230 minutes). Median blood loss was 1680 cc (range, 300-6900 cc). In our early experience, 2 patients died of myocardial infarction. Ten major nonlethal postoperative complications were observed in 8 patients: 4 transcient renal insufficiencies, 2 cases of lung atelectasis, 1 bowel obstruction, 1 spleen rupture, 1 external iliac artery dissection, and 1 iliac hematoma. Others patients had an excellent recovery with rapid return to general diet and ambulation. Median hospital stay was 9 days (range, 8-37 days). With a median follow-up of 12 months (range, 0.5-20 months), patients had a complete recovery and all grafts were patent.

CONCLUSION

These preliminary results show that total laparoscopic AAA repair is feasible and worthwhile for patients once the learning curve is overcome. However, prior training and experience in laparoscopic aortic surgery are needed to perform total laparoscopic AAA repair. Despite these encouraging results, a greater experience and further evaluation are required to ensure the real benefit of this technique compared with open AAA repair.

[Laparoscopic aortoiliac surgery for occlusive disease and or aneurysms]

The techniques of video-assisted surgery have been recently applied to aortoiliac surgery. The choices between first the retroperitoneal approach or the transperitoneal approach and the place of video-assisted surgery in relation to totally laparoscopic surgery are at the centre of debates. The aim of this clarification is to relate the evolution of laparoscopic aortoiliac surgery for occlusive disease and aneurysms through a review of the literature on this subject.