Arterial repair with synthetic patch by using titanium clips

BACKGROUND: Vascular closure staple (VCS) clips made of titanium were originally developed for microvascular anastomoses. There is limited experience with their applicability to vascular reconstruction in larger vessels. This study compares VCS clips to standard sutures in arterial repair using a synthetic patch. METHODS: In an experimental study with pigs, two sequential 10-mm abdominal aortotomies were allocated randomly to synthetic patch (polytetrafluoroethylene) repair with VCS clips or continuous 6-0 polypropylene sutures. Angiographic, macroscopic, and microscopic results were assessed after 2 months. RESULTS: There were no significant differences in the patency rate, vessel diameter at the repair site, or healing indices. The mean (SD) clamp time was 8.7 (3.0) minutes for clip repair and 14.3 (7.4) minutes for suture repair (p = 0.04), and the times required for the vessel reconstruction were 5.3 (1.3) and 9.3 (3.0) minutes, respectively (p = 0.009). CONCLUSION: Patched arterial repair with VCS clips is faster than sutured reconstruction with comparable results after 2 months of follow up.     

A comparison of para-anastomotic compliance profiles after vascular anastomosis: nonpenetrating clips versus standard sutures

PURPOSE: Anastomotic compliance is an important predictive factor for long-term patency of small diameter vascular reconstruction. In this experimental study we compare the compliance of continuous and interrupted sutured vascular anastomoses with those using nonpenetrating clips. METHODS: Both common carotid arteries in nine goats (average weight, 57 +/- 5.7 kg) were transected, and end-to-end anastomoses were constructed with nonpenetrating clips or polypropylene sutures. The latter were applied with both interrupted and continuous techniques. Intraluminal pressure was measured with a Millar Mikro-tip transducer, and vessel wall motion was determined with duplex ultrasound equipped with an echo-locked wall-tracking system. Diametrical compliance was determined. Environmental scanning electron microscopy was performed on explanted anastomoses. RESULTS: There was a reduction in anastomotic compliance and associated proximal and distal para-anastomotic hypercompliant zones with the use of all techniques. However, compliance loss was significantly less in those anastomoses with clips and interrupted sutures when compared with continuous suture (P <.001). Furthermore, the total compliance mismatch across anastomoses with continuous sutures was significantly greater than those with clips or interrupted sutures (P <.05). The mean time for constructing clipped anastomoses was 5.7 +/- 1.4 minutes, which was significantly less than either continuous (P <.0001) or interrupted sutures (P <.0001). Furthermore, environmental scanning electron microscopy demonstrated minimal intimal damage with good intimal apposition in the clip group. CONCLUSION: Anastomoses performed with nonpenetrating clips resulted in improved para-anastomotic compliance profiles and reduced intimal damage when compared with those with polypropylene sutures. These benefits may enhance long-term graft patency by reducing the risk of anastomotic intimal hyperplasia.     

Preservation of endothelial integrity and function in experimental vascular anastomosis with non-penetrating clips

BACKGROUND: Vascular repair with sutures is associated with disruption of the endothelial lining and subsequent thrombus formation on the intraluminal lesions. This experimental study was designed to determine whether the use of non-penetrating clips improved endothelial preservation. METHODS: In ten female pigs, 25-mm arteriotomies were made in both carotid arteries. The arteriotomies were repaired with jugular vein patches. On the left side, the repair was done with 1.4-mm titanium clips, and on the right side with two running 6/0 polypropylene sutures. Next, the aorta was divided and subsequently repaired with 2-mm clips in five of these pigs, and with two running 5/0 polypropylene sutures in the remaining five pigs. Endothelial function was studied at the anastomotic site in the carotid arteries by determination of endothelium-dependent and -independent relaxatory responses. Morphometric examination of the carotid arteries and inspection of the aortic endothelium were performed by means of scanning electron microscopy. RESULTS: Maximal endothelium-dependent relaxation to adenosine 5'-diphosphate was less in sutured than in clipped carotid arteries (P < 0.05), while there was no difference in maximal endothelium-independent relaxation to sodium nitrite. This result in clipped carotid arteries was not accompanied by less intimal hyperplasia. Screening of the aortic anastomotic line showed better preservation of endothelial architecture after clip anastomosis. Mean cross-clamp time for carotid patch repair was significantly less when using clips than with sutures. CONCLUSION: The use of non-penetrating clips for vascular anastomoses preserved endothelial function and structural integrity better than running sutures, although the degree of intimal hyperplasia was similar.     

A multicenter study of permanent hemodialysis access patency: beneficial effect of clipped vascular anastomotic technique

OBJECTIVE: There is an urgent and compelling need to reduce the morbidity and expense of maintaining hemodialysis vascular access patency. This large, long-term, retrospective, multicenter study, which compared access patency of autogenous arteriovenous fistulas (AVF) and synthetic bridge grafts (AVG) created with conventional sutures or nonpenetrating clips, was undertaken to resolve conflicting results from previous smaller studies. DESIGN: Patency data for 1385 vascular access anastomoses (clipped or sutured) was obtained from 17 hospitals and dialysis centers (Appendix). Five hundred eighteen AVF (242 clip, 276 suture) and 827 AVG (440 clip, 384 suture) were analyzed. Statistical comparisons were made with Kaplan-Meier survival analysis, log-rank test, two-sample t test, and X(2) test. The Cox proportional hazards model was used to confirm Kaplan-Meier analysis. RESULTS: Access patency (primary, secondary, overall, and intention to treat) was significantly improved in access anastomoses constructed with clips. In the intention-to-treat group, primary patency at 24 months was 0.54 for clipped AVF and 0.34 for sutured AVF, and was 0.36 for clipped AVG and 0.17 for sutured AVG. At 24 months, primary patency rate for AVF successfully used for dialysis was 0.67 for clips and 0.48 for sutures, and for AVG was 0.39 for clips and 0.19 for sutured constructs. Interventions necessary to maintain patency were significantly fewer in clipped anastomoses. CONCLUSION: Replacing conventional suture with clips significantly reduces morbidity associated with maintaining permanent hemodialysis vascular access. This beneficial effect may be due to the biologic superiority of interrupted, nonpenetrating vascular anastomoses.     

Comparison of arcuate-legged clipped versus sutured hepatic artery, portal vein, and bile duct anastomoses

Attempts at improving anastomoses have included the development of stapling techniques. Our purpose was to evaluate arcuate-legged clipped versus standard sutured anastomoses of the hepatic artery (HA), portal vein (PV), and bile duct in a porcine liver transplantation model. Two groups of pigs were studied intraoperatively and 1 day after liver transplantation. A control group underwent sutured anastomosis of PV and HA with polypropylene and of bile duct with polydioxanone (n = 8). An experimental group underwent anastomoses with arcuate-legged clips (n = 8). We analyzed the time to perform anastomosis and flows before and at various time points after anastomosis. In addition, patency and histology of the anastomoses were evaluated 1 day after operation, including a fibrin-thrombosis score, medial injury, and inflammation score. Times to complete HA and PV anastomoses were not different between clipped and sutured groups. However, the time was shorter to complete bile duct anastomosis with clips than with sutures (6.3 +/- 1.1 minutes and 13.3 +/- 2.0 minutes, respectively). Flows through HA anastomoses were not different between groups, but flow through the PV was higher in clipped compared with sutured anastomosis (P = 0.06). Patency was 100 per cent with no leaks for all three anastomoses in both groups. Histologic data were similar between vascular anastomotic groups. Sutured bile duct anastomoses revealed mild smooth muscle injury in 75 per cent whereas clipped bile duct anastomoses displayed no smooth muscle injury. We conclude that arcuate-legged clipped anastomosis represents a viable option to sutured anastomoses of the PV, HA, and bile duct anastomoses. Bile duct anastomoses were completed in less than half the time and with less tissue damage documented histologically.     

In search of the "perfect" anastomosis

Forty-five end-to-side microvascular anastomoses were completed in rat carotid arteries of 0.7-0.8 mm diameter (anastomosing the distal end of the left common carotid to the side of the right common carotid). For comparison both 10-0 and 11-0 sutures were utilized in different anastomotic techniques: interrupted, direct-continuous, and diagonal-continuous sutures, plus total mural thickness vs. partial mural thickness (piercing only the adventitia and outer media, excluding the intima). Anastomoses were evaluated for patency and scanning electron microscopic appearance after 10 to 12 weeks. The results indicate complete patency in all anastomoses. Ultrastructural observations revealed nearly normal intimal appearance in the partial medial technique and only minimal evidence of intimal injury in the other techniques. It is concluded that 100% patency can be obtained regardless of suture size or anastomotic technique. The most important factor in anastomotic patency is the operator's technical skill.     

Laser welded vascular anastomosis

Summary A comparative study was undertaken to investigate the application of a specially adapted microsurgical Neodymium Yag Laser system with a wavelength of 1,319 m and a CO₂ laser system for laser assisted microvascular end-to-end anastomosis (LAMA) of the rat femoral artery. Conventionally sutured anastomoses served as controls. Postoperative investigations included patency tests, light microscopy and tensile strength measurements. Both laser systems seem to be equally suitable for LAMA: The patency rates do not differ from those of sutured anstomoses and formation of microscopically small aneurysms occurred predominantly in control animals and only once in laser groups. The clamp time needed for LAMA was half the time that was needed for sutured anastomoses. Wound healing in all groups was similar with less fibrotic reactions and less foreign body granulomas in laser groups. At all intervals tensile strength was significantly higher for sutured anastomoses while differences between the CO₂- and the ND: Yag-laser groups were not statistically significant. Potential applications in urology include microvascular anastomoses in erectile dysfunction, pediatric and reconstructive urology.Contains parts of a dissertation     

Randomized clinical trial of continuous sutures or non-penetrating clips for radiocephalic arteriovenous fistula

BACKGROUND: Despite several modifications to the original design, patency rates of radiocephalic arteriovenous fistulas have changed little since the first report in 1966. The use of non-penetrating clips for vascular anastomosis on the outcome of such fistulas was studied. METHODS: Between January 2000 and August 2003, 107 primary radiocephalic fistulas were constructed in 98 patients. The vascular anastomoses were performed at random with either sutures (n = 56) or clips (n = 51). RESULTS: Although there were trends for better primary and primary assisted patency of clipped fistulas, the differences were not statistically significant. The 6-month primary patency rate was 61 per cent with sutures and 69 per cent with clips (P = 0.393). The mean(s.d.) primary patency was 315(306) and 285(285) days for clipped and sutured fistulas respectively. With regard to secondary patency, clipped fistulas were better (P = 0.009). The mean(s.d.) secondary patency was 435(376) and 344(316) days for clipped and sutured fistulas, respectively. There were no significant differences in flow characteristics, number of revisions or other morbidity. CONCLUSION: This randomized clinical trial provided further evidence that the use of vascular clips may improve the patency rate of radiocephalic arteriovenous fistulas for haemodialysis.     

Comparison of tensile strength and thrombus formation between mechanical microvascular anastomoses using a biodegradable ring device and sutured anastomoses

The purpose of this study was to evaluate whether early motion following mechanical anastomosis using a biodegradable ring device was possible or not, by measuring tensile strength and the rates of thrombus formation at anastomotic sites. Bilateral femoral arteries and veins of 24 rabbits were repaired by sutured anastomoses and biodegradable ring anastomoses. The tensile strength of the anastomotic site was measured by constant loading with a material-testing machine, using specimens excised at 24 hr, 72 hr, 1 week, and 2 weeks after anastomosis. The tensile strength of biodegradable ring arterial anastomoses was significantly stronger than sutured anastomoses at 24 hr, 72 hr, 1 week, and 2 weeks. No statistically significant differences were observed in venous anastomoses at any interval. In separate experiments, biodegradable ring anastomoses and sutured anastomoses of the bilateral femoral arteries of 18 rabbits were constructed, and early passive knee motion was carried out at 100 times once a day with maximum spreading of the hip joint for 24 hr, 72 hr, and 1 week. Thrombus formation at the anastomotic sites was evaluated by scanning electron microscope (SEM). SEM showed no thrombus formation in the biodegradable ring anastomoses at any interval; however, thrombi were observed in the sutured anastomoses (33 to approximately 50 percent).     

Anastomotic tissue response associated with expanded polytetrafluoroethylene access grafts constructed by using nonpenetrating clips.

PURPOSE: The gross, light microscopic, and scanning microscopic appearance of arterial and venous anastomoses in expanded polytetrafluoroethylene (ePTFE) access grafts constructed with nonpenetrating clips were compared with that of those constructed with polypropylene suture. We hypothesized that clip-constructed anastomoses would provide controlled approximation of native vessel intimal and medial components with the ePTFE grafts. We further hypothesized that anastomotic healing with clips would involve primarily an intimal cellular response, as compared with suture-constructed anastomoses in which cells within the media and adventitia walls participate. METHODS: Femoral artery to femoral vein arteriovenous (AV) grafts were constructed in five dogs using 4-mm internal diameter ePTFE graft material. Each animal received one AV graft with anastomoses constructed by using polypropylene sutures in one leg and one AV graft with anastomoses constructed with Vascular Closure System clips in the contralateral leg. Animals were given aspirin for the duration of the study, and grafts were explanted at 5 weeks. At the time of explantation, graft segments were grossly evaluated and then underwent light and scanning electron microscopic analysis. RESULTS: At the time of explantation, all access grafts were patent. Joining the ePTFE grafts to the native vessels with clips resulted in minimal vessel wall damage. The lumenal contours of the discontinuous approximation were smooth and without gross endothelial disruption. These observations are in contrast to the lumenal compromise and endothelial disturbance associated with the sutured anastomoses. Furthermore, hemostasis was achieved immediately in the clipped grafts, decreasing the incidence of perianastomic hematoma. Finally, cellular reconstitution occurred at the anastomotic cleft in both the sutured and the clipped junctions. The neointima exhibited an endothelial cell lining on the lumenal surface and the presence of alpha-smooth muscle cell actin positive cells within the subendothelial layer. CONCLUSION: Vascular Closure System clips are a viable alternative to suture for the approximation of ePTFE AV access grafts to native blood vessels. The use of the clips resulted in a more streamlined anastomosis, with decreased vessel wall damage, immediate hemostasis, and a trend toward shorter procedure times.     

Microvascular anastomosis using the vascular closure device in free flap reconstructive surgery: A 13-year experience

The achievement of patency of the microvascular anastomosis in free flap surgery is dependent on a number of factors, central to which is atraumatic handling of the vessel lumen, and intimal apposition. Initial laboratory studies demonstrating the superiority of the non-penetrating vascular closure staple (VCS - Anastoclip ?) were followed by our report in 1999 on a series of free flaps. There is still a paucity of data in the literature on the use of non-penetrating devices for microvascular anastomosis, and our review gives evidence to support the routine use of the VCS in microsurgical free flap surgery. We now report on its successful use over a thirteen year period in 819 free flap reconstructions. Our data indicates the VCS device to be as effective as sutured anastomoses in free tissue transfer surgery. There is also statistically significant data (Barnard's Exact Test) to demonstrate a higher vascular patency rate of the VCS device over sutured anastomoses when sub group analysis is performed. 'Take-back' revision rates were lower amongst flaps that employed VCS use. For arterial anastomoses, this equated to 3/654(0.05%) vs 4/170(2.4%) with hand-sewn anastomoses (p?=?0.02). Similarly, for venous anastomoses the 'take-back' revision rate was 7/661(1.1%) vs 8/165(4.8%) with hand-sewn anastomoses (p?=?0.003). Furthermore, the major advantage of the VCS is reduction in anastomosis time, from approximately 25?min per anastomosis for sutures to between five and 10?min for staples.     

Enabling sutureless vascular bypass grafting with the exovascular sleeve anastomosis

PURPOSE: We describe a technique for end-to-end sleeve anastomosis that may enable minimally invasive bypass grafting and characterize the tensile strength, stenosis rate, durability, and healing of the anastomosis. METHOD: An anastomotic device assembly consisting of a cable tie-type band with mobile teeth elements is mounted on the outer surface of a polytetrafluoroethylene graft. The graft is drawn over the artery resulting in a sleeve of vessel within the graft. As the band is tightened over an intraluminal obturator, the independently mobile anchoring teeth are driven through the graft into the artery. The tensile strength of the anastomosis was compared with sutured anastomosis during in vitro studies using cadaveric human femoral arteries. For in vivo studies on pigs and goats, we used a proximal exovascular sleeve anastomosis along with a distal sutured aortic anastomosis. Survival animals were studied by angiogram postoperatively and at the time of explantation. RESULTS: In vitro studies showed no difference in maximal tensile strength between sutured and exovascular anastomoses (10.5 +/- 2.7 lb vs 10.2 +/- 3.0 lb, P =.83). However, loss of continuous graft to artery interface occurred at lower loads in the sutured anastomoses (6.5 +/- 0.6 lb, P <.05). In total, all 24 pigs tested in nonsurvival or survival settings sustained a successful and leakproof anastomosis. Of the 13 nonsurvival cases, maximal epinephrine-induced hypertension sustained over 15 minutes (peak systolic blood pressure > 210-250 mm Hg) was tolerated without leakage in a subgroup of five animals (100%). All 11 survival pigs had no pseudoaneurysms or stenosis relative to sutured control anastomoses at 6 week explantation (8.2 +/- 1.25 mm vs 8.5 +/- 1.6 mm, P =.21). The three long-term survival goats had no pseudoaneurysm or stenosis after 40 weeks. Histologic examination confirmed healing of the aorta to graft with minimal neointimal hyperplasia. CONCLUSION: Exovascular sutureless anastomosis appears comparable to sutured anastomosis in stenosis rate, healing, and durability, with some advantages in tensile strength and rapidity of application.     

手术缝线携载反义基因预防血管吻合口内膜增生的实验研究

目的：探讨预防血管吻合口内膜增生的新方法。了解手术缝线携载反义基因对吻合口内膜增生的影响。方法：用分别浸泡过反义，正义及错配c-myc基因溶液的保护薇乔缝线行兔颈外静脉间置于同侧颈总动脉的血管吻合。实验动物24只随机分为对照组，反义组，正义组和错配组，每组6只，4周后血管造影观察吻合口通畅情况，同时取材制片显微镜下观察其内膜增生情况，计算机图像分析测量其内膜，中膜厚度及两者比值；内膜，中膜面积及两者比值。结果：所有吻合口通畅，未见闭塞，扩张或动脉瘤，反义组的内膜厚度，内膜／中膜厚度比值及内膜面积，内膜／中膜面积比值较其他组均低（P＜0．05），其他3组间比较差异均无显著意义（P＞0．05）；各组间的中膜厚度及中膜面积间差异无显著意义（P＞0．05），结论：用浸泡过反义 c-myc溶液的保护薇乔缝线进行血管吻合，能有效地抑制血管吻合口内膜增生。     

Alternative techniques for management of distal anastomoses of aortofemoral and iliofemoral endovascular grafts

PURPOSE: Techniques for managing the distal anastomoses of aortofemoral and iliofemoral endovascular grafts are described. METHODS: Over a 2(1/2)-year period 46 endovascular grafts were successfully placed to treat severe iliac artery occlusive disease. Endovascular grafts were anchored proximally in the distal aorta or iliac arteries with Palmaz balloon-expandable stents. The distal anastomoses were performed with the use of open, sutured anastomotic techniques. In contrast to stented distal anastomoses, these techniques allowed us to (1) treat occlusive lesions extending from the distal aorta to below the inguinal ligament, (2) terminate endovascular grafts in the groin where stents are contraindicated, (3) vary the distal anastomotic site depending on the local pattern of disease, and (4) standardize the preinsertion length of the endovascular graft. RESULTS: Two distal perianastomotic stenoses and one graft occlusion were detected postoperatively in 11 bypass grafts that had distal anastomoses sewn endoluminally without an overlying patch angioplasty. Only one perianastomotic stenosis was found among 35 anastomoses performed with other techniques. There were no significant differences in primary and secondary patency between grafts originating in the distal aorta or iliac arteries. CONCLUSIONS: Hand-sewn distal anastomoses can simplify the insertion of endovascular grafts used for the treatment of aortoiliac occlusive disease. These anastomoses permit tailoring of the graft according to the patients' pattern of disease and eliminate the need to precisely measure the length of the graft preoperatively. In addition, because a distal stent is not required, endovascular grafts can be safely terminated in the groin instead of the external iliac artery where disease progression can lead to graft failure. Finally, endovascular distal anastomoses should be closed with a patch or the hood of a more distal bypass graft to prevent perianastomotic stenoses or occlusions in the postoperative period.     

Clinical experience with non-penetrating vascular clips in free-flap reconstructions.

To date, the gold standard for performing a microvascular anastomosis has been the penetrating suture with attached needle. During the last two decades, non-penetrating techniques have been introduced, including the Unilink system for end-to-end anastomoses, and the VCS clip-applier system for both end-to-end and end-to-side anastomoses. The aim of this study was to compare the results of different techniques used to create microvascular anastomoses in free-flap reconstructions. Between January 1995 and October 1999, we performed 474 microvascular anastomoses in 216 consecutive free-tissue transfers. The anastomosis techniques included manual sutures (42%), Unilink rings (34%) and VCS clips (24%). Seven combined sutured-clipped anastomoses were excluded from further analysis. The mean anastomotic time when rings were applied was significantly shorter than when using clips (P 0.0001) or sutures (P 0.0001). Venous anastomoses using clips took less time than those using sutures (P 0.05). There were 19 anastomotic failures, all of which lead to early flap failure. Ten flaps were salvaged by early reoperation; nine flaps were lost. Three more flaps were lost as a result of other causes, bringing the flap survival rate down to 94.4%. Early flap failure was caused by failure of the arterial anastomosis in eight cases; all of them were sutured (these represented 5% of all arterial anastomoses with sutures). None of the clipped arterial anastomoses failed. Early flap failure was caused by failure of the venous anastomosis in 11 patients. Three of these anastomoses were sutured (representing 6% of all venous anastomoses with sutures), seven were anastomosed with rings (representing 5% of all venous anastomoses with rings) and one was clipped (representing 2% of all venous anastomoses with clips). Both the VCS clip-applier system and the Unilink system are easy to handle and allow fast microvascular anastomoses without intraluminal penetration. The patency rate of clipped vessels is at least as good as the patency rates of vessels anastomosed using sutures or rings.     

Vascular anastomoses with laser energy

Laser-assisted arterial and venous anastomoses are now feasible. A microscope-guided CO2 laser was used to deliver 60 to 100 mW to anastomose end to end 44 rabbit carotid arteries (1.5 to 2.0 mm) and 27 rabbit vena cavae (4 to 6 mm). These were compared with control arteries repaired with interrupted suture technique. Anastomoses were examined from between 24 hours and 19 weeks. Laser carotid anastomoses yielded 93% patency (41 of 44) and 9% aneurysms (4 of 44), whereas hand-sewn carotid anastomoses produced 91% patency (40 of 44) and no aneurysms. In the vena cava, 26 of 27 laser anastomoses were patent (96%) compared with 19 of 20 (95%) sutured controls. Venous aneurysmal dilatation was seen in 2 of 27 laser (7%) and in 3 of 20 (15%) hand-sewn anastomoses. Histologic examination of laser-assisted anastomoses showed local full-thickness thermal injury. Repair was by fibroblast and myofibroblast proliferation, and luminal cell coverage was complete by 14 days in both laser and sutured repairs. Laser arterial and venous anastomoses are attractive because of their simplicity and rapidity of performance. Their patency is comparable to sutured anastomoses, but arterial aneurysms remain a hazard despite use of extremely low laser energy.     

Bursting strength in CO2 laser-assisted microvascular anastomoses

Iliac artery end-to-end anastomoses were performed in 42 Sprague-Dawley rats, divided into seven groups, to determine the welding effects of CO2 laser radiation in microvascular anastomoses. Conventional suture techniques were performed on right iliac arteries, and left iliac arteries were anastomosed with a laser-assisted technique. Bursting strength and diameters of the anastomotic sites were measured at different intervals (from one day to five weeks) post surgery. The anastomotic patency rate was 100 percent in both groups, and the aneurysm rate was only 2 percent in the laser group. Bursting strength was low at one and three days post surgery in both groups; then, it increased gradually until both groups could withstand higher than physiologic pressures. Results of high patency rates, low aneurysm formation, and the ability to withstand pressures higher than physiologic, suggest that the laser-assisted anastomotic technique can play an important role in microvascular surgery.     

Vascular Closure System Type of Nonpenetrating Arcuate-Legged Titanium Clips for Graft-Artery and Graft-Graft Anastomoses: Review of Our Clinical Experience

Purpose To assess the durability of Vascular Closure System (VCS) clips for graft-artery and graft-graft anastomoses.Methods The subjects were 100 consecutive patients, who had undergone vascular procedures in which VCS clip application was attempted for anastomoses. The operative indications were arteriosclerosis obliterans in 69 patients, aortic aneurysm in 26, and other disorders in 5. Large clips were used for both graft-artery and graft-graft anastomoses, and medium-sized clips were used for the smaller caliber femoral or popliteal arteries.Results Vascular Closure System clips could not be applied to anastomose the graft to the artery in 13 patients because the arterial wall was too thick or stiff. Anastomosis was accomplished without any problems in 80 patients, although suture-line bleeding occurred in 7 patients. This was ameliorated by an additional clip in four patients, but interrupted sutures were needed to seal the anastomosis in the other three patients. The 1-, 3-, and 5-year cumulative primary patency rates were 98.7%, 97.4%, and 87.7%, respectively. There were two graft failures and two anastomotic aneurysms.Conclusion Vascular Closure System clips were useful to coapt a prosthetic graft to an artery unless the arterial wall was thicker than 2mm or calcified. Thus, VCS clips could be durable enough for graft-artery anastomoses in the iliac or popliteal region.     

Sutureless anastomoses of small and medium sized vessels by medical adhesive.

PURPOSE: Using an animal model we have assessed sutureless anastomoses. METHODS: The two cut ends of the rabbit common carotid artery were sutured by three stitches with a 120 degrees interval circumferentially, then two optional threads were pulled horizontally and 0.1 ml adhesive was smeared on the attached surface of the two ends. The three stitches were removed after completion of anastomosis. The burst pressure of the anastomosis was measured and compared with that of a traditional sutured artery. RESULTS: The glued anastomosis was associated with: a shorter completion time (8.25+/-6.34 min vs. 20.67+/-14.24 min, P<0.01), less bleeding (3.17+/-9.04 ml vs. 11.04+/-16.28 ml, P<0.01), and equivalent patency (93.8 vs. 87.5%, P>0.05). The sutureless anastomosis was associated with less intimal thickening (decreased by 31.4, 24.5, 23.9 and 31.9%, P<0.01 compared with the traditional suture group at 1, 2, 4 and 12 weeks, respectively). CONCLUSION: Glued anastomoses provides an effective, simple and feasible way for anastomosing small or medium caliber vessels. This technique may reduce intimal injury.     

Argon laser-welded arteriovenous anastomoses

This study compared the healing of laser-welded and sutured canine femoral arteriovenous anastomoses. Arteriovenous fistulas 2 cm in length were created bilaterally in the femoral vessels of 10 dogs and were studied at 1 (n = 2), 2 (n = 2), 4 (n = 3), and 8 (n = 3) weeks. In each animal, one anastomosis (control) was closed with running 6-0 polypropylene sutures, and the contralateral anastomosis (experimental) was sealed with an argon laser (0.5 watt, 4 minutes of exposure, 1830 J/cm2/1 cm length of anastomosis). At removal all experimental anastomoses were patent without hematomas, aneurysms, or luminal narrowing. Histologic examination at 4 weeks revealed that laser-welded anastomoses had less inflammatory response and almost normal collagen and elastin reorientation. At 8 weeks sutured anastomoses had significant intimal hyperplasia whereas laser repairs had normal luminal architecture. Tensile strength and collagen production, measured by the synthesis of hydroxyproline and the steady-state levels of type I and type III procollagen messenger ribonucleic acids, at the anastomoses and in adjacent vein and artery specimens were similar in sutured and laser-welded repairs at 2, 4, and 8 weeks. We conclude that argon laser welding of anastomoses is an acceptable alternative to suture techniques, with the advantage of improved healing without foreign body response and possible diminished intimal hyperplasia at the anastomotic line.