Conventional Suture Anastomosis Research Articles

An Arteriovenous Fistula Model of Intimal Hyperplasia for Evaluation of a Nitinol U-Clip Anastomosis

Objectives The aim of this study was to create an ovine arteriovenous fistula (AVF) model which would closely replicate a human forearm fistula and use this to quantify the degree of intimal hyperplasia in those created with the U-Clip compared to a conventional sutured anastomosis. Materials and methods Twenty AVFs were created in 10 Border Leicester–Merino sheep between the superficial femoral artery and vein of each hind limb. On one side the U-Clip and on the other a continuous polypropylene suture was used to perform the anastomosis. The animals were sacrificed at 2 ( n = 3), 4 ( n = 4), 6 ( n = 3) weeks and histological slices were taken of each AVF in cross section to determine the intimal media area per unit length (IMA/L). Results Intimal hyperplasia (IH) was observed at all time points with one AVF found occluded with thrombus at the time of harvest. The IMA/L was significantly lower in the U-Clip groups by 24% at 2 weeks, 32% at 4 weeks and 23% at 6 weeks (Two-way ANOVA, p = 0.019, observed power = 0.825, time or side p ≥ 0.766, type p = 0.001; Paired t-test, p < 0.001 between matched anastomotic types). Time taken to perform the anastomosis was similar between the two anastomotic techniques (Polypropylene 14(8–18) vs. U-Clip 15.3(11–23) min; p = 0.47). Conclusion This ovine AVF model results in IH similar to that seen in a human AVF. The IH that occurs with the U-Clip is less than that of continuous polypropylene suture.

Experimental analysis of tensile force of individualized stents for microvascular anastomoses

The aim of this project was to investigate the fundamental idea of the possibility of anastomosing small blood vessels in microvascular transplant procedures by an individualized stent known from coronary angioplasty. We investigated the influence of length, dilation and differences in fabrication of the newly developed balloon-expandable stent on the tensile force of stented anastomoses. Various gripping devices were tested and validated to investigate how the length, dilatation and differences in fabrication of the newly developed stent influence the tensile force of the stented anastomosis. Overall, 66 arteries of thiel-fixed human cadavers were investigated, divided into 11 groups. The median tensile force in sutured anastomoses was 2.96 N. The stented anastomoses with 24 mm stents and Ø 3.5 mm dilation attained approximately two-thirds of F(max)-values compared with conventional sutured anastomoses. If the stent was less dilated or had a shorter length, the maximum tensile force of the anastomosis was lower. Recent developments with an inversely oriented stent structure are expected to achieve even higher tensile force values. Further research in stent design to reduce leakage is necessary. A reduction of stent and catheter dimension is also needed to enhance the implantation method.

Novel sutureless telescoping anastomosis revascularization technique of supra-aortic vessels to simplify combined open endovascular procedures in the treatment of aortic arch pathologies

We report our clinical experience with the use of a sutureless telescoping anastomosis, initially described as the VORTEC (Viabahn Open Rebranching TEChnique) revascularization technique, for debranching of supra-aortic vessels. Between May 2005 and December 2008, 20 patients (15 men) with an aortic arch lesion underwent trans-sternal debranching with sutureless telescoping anastomosis performed with a Viabahn (diameter, 5-8 mm; length, 5-15 cm) or Hemobahn (diameter, 9-13 mm; length, 10-15 cm), followed by endovascular aneurysm repair. Initially, the Viabahn/Hemobahn was sutured to a feeding graft after deployment. Since 2008, the Viabahn/Hemobahn has been deployed within an interposition graft, rendering unnecessary the anastomosis. The underlying aortic pathology was (1) isolated aortic arch aneurysm in 10, (2) aortic arch aneurysm extending to the ascending or descending aorta in 6, (3) floating thrombus within the aortic arch in 1, (4) acute aortic arch dissection in 1, and (5) Crawford II thoracoabdominal aortic aneurysm extending into the aortic arch in 2. Postprocedural duplex ultrasound imaging showed normal flow profiles in all patients. Follow-up included computed tomography angiography at 1, 3, and 6 months postoperatively, and then annually. Overall, 56 supra-aortic vessels in the 20 patients were debranched by sutureless telescoping anastomosis, including the carotid artery in 18, subclavian artery in 13, and left vertebral artery in 1. Technical success was 100%. The mean ischemia time was 3 minutes (range, 1-9 minutes) for the debranching procedure vs 6 minutes (range, 5-16 minutes) for a conventional suture anastomosis. The 30-day mortality rate was 15% (3 if 20); 28.5% (2 of 7) in urgent cases and 7.6% (1 of 12) in elective patients. Three patients (15%) had neurologic deficits after debranching in the conventionally-sutured anastomosis territories. No early (<30 days) occlusion occurred. During a mean follow-up of 14 +/- 9 months (range, 1-39 months), one patient with Takayasu disease showed asymptomatic occlusion of a Viabahn implanted into the left common carotid artery. Stenosis in the aortic anastomosis of the bypass graft in another patient was successfully treated by angioplasty and stent placement through the right brachial artery. Sutureless telescoping anastomosis with a Viabahn or a Hemobahn in supra-aortic debranching seems to be a safe and reliable alternative to sutured anastomosis. It enables safe and fast-track revascularizations, especially in anatomically challenging situations, and requires a very short ischemia time. Questions about long-term results and the technique reproducibility must be addressed.

Suture-Free Small Bowel Anastomoses Using Collagen Fleece Covered with Fibrin Glue in Pigs

Background: Several studies investigating anastomotic healing could objectify that the regularly used suture material leads to an impairment of wound healing due to ischemia at the anastomotic line. This study was initiated to test a hypothesis that a reduction of suture material leading to suture-free glued intestinal anastomoses is feasible and enables an improved wound healing. Materials and Methods: Three different types of anastomoses were carried out at the small bowel of 16 pigs. Standard hand-sewn anastomoses, anastomoses with loose-fitting skin staples, and suture-free glued anastomoses using a fibrin covered collagen fleece. When the animals were killed, both gross inspection of the parietes, bursting pressure and tissue for histological study became the basis for evaluation. Analyses were also made regarding the collagen I/III ratio and the expression of MMP 1 and 13. Results: Four leakages at the stapled, one at the sutured, and one at the glued anastomoses occurred. All other anastomoses healed without complications. The bursting pressure did not differ significantly between the groups. The macroscopic inspection and the microscopic examination both showed an improved healing pattern for the material reduced techniques without onset of a deep ulcer at the anastomotic line as seen at the conventional sutured anastomoses. These findings were supported by the immunohistochemical studies. Conclusions: These observations suggest that a suture-free bowel anastomoses using collagen fleece covered with fibrin glue is technically feasible. Obviously, a reduction of foreign body material at the anastomotic line avoids unnecessary ischemia and thus supports a physiological improved wound healing process.

Trial of new vascular clips for aortic anastomosis in a canine model

We created a new vascular clip designed for aortic surgery. The purposes of this investigation were to examine surgical applicability in a clinically relevant aortic replacement model and to assess biomechanical strength of the clipped anastomosis and serial histologic changes in the clipped anastomotic site. Twenty-one beagles underwent descending thoracic aortic replacement. Distal anastomosis was performed with the new clips, mimicking the cuffed anastomosis technique, and proximal anastomosis was carried out by conventional suture anastomosis. Tissue specimens of the anastomotic sites were harvested at 1, 3, 6, and 12 months postoperatively for examination. There was no significant difference in the time required to carry out clip anastomosis (12.2 +/- 1.3 minutes) and suture anastomosis (13.7 +/- 0.9 minutes; P = .38). Neither type of anastomotic site was disrupted by raising the intraluminal pressure to 280 mm Hg. Microscopically, the areas of aortic wall compressed by vascular clips appeared as hyalinized areas adjacent to surrounding collagen fibers, with no significant infiltration of inflammatory cells. Identical histologic changes were observed at the site of the sutured anastomosis. The media at the clipped anastomosis site was significantly thinner than that at the sutured anastomosis site at 1 month after the operation. However, there was no significant difference in the thickness of the media at 3 months. The new vascular clips were effective in this clinically relevant model, with appropriate biomechanical strength, and the anastomotic sites underwent similar histologic changes to those observed after suture anastomosis.

Microvascular Anastomosis with Minimal Suture and Arista: An Experimental Study

The conventional technique of microvascular anastomosis may cause trauma to the vessel wall. In addition, the technique is difficult for beginners and is time consuming. The duration of ischemia is an important limiting factor for muscle transfer. In the case of multiple-digit replantations, fatigue developed in the surgeon may also result in suboptimal results. This study was performed to establish an easier and shorter method of microvascular anastomosis using the Arista hemostatic agent. In this study, 20 carotid arteries obtained from rats were equally divided into two groups. The arteries were then divided and repaired using three simple interrupted stay sutures with Arista powder. Evaluations were performed using the following three methods: (1) clamping time during the vessel anastomosis, (2) patency test (after 1 hour, 24 hours, and 28 days), and (3) light microscopic findings. The clamping time in the conventional suture anastomosis group was 21+/-4 minutes, whereas that of the minimal suture in the Arista group was 12+/-2 minutes; the difference between the two groups was statistically significant (P<.001). There was no significant difference between the patency rates of the two groups (P= .474). It was observed that the Arista group showed qualitatively less perivascular foreign-body giant cell reaction than the control group. There was no evidence of vascular mural fibrinoid necrosis, indicating that Arista was nontoxic for the vessel walls. The Arista-assisted microvascular anastomosis is an alternative to the conventional suture-only method because it reduces the anastomosis time significantly and does not cause narrowing of the vessel wall. We believe that this technique has the potential for improving the performance of microvascular anastomosis in clinical practice.

Influence of anastomotic techniques in totally endoscopic coronary artery bypass

Beating heart totally endoscopic coronary artery bypass grafting (TECAB) utilizing a computer-enhanced telemanipulation system is a technically challenging procedure. The objective of our study was to compare two different anastomotic techniques. Ten canine beating heart TECAB procedures were performed using Intuitive's daVinci surgical system. Left internal mammary artery (LIMA) to left anterior descending coronary artery (LAD) anastomosis was performed on all subjects. Anastomosis varied between a conventional running suture (8-0 Gore-tex) (group I) and an interrupted nitinol u-clip anastomosis (group II). On-table angiography was then performed to assess graft patency. While internal mammary artery (IMA) mobilization time decreased over the course of the study (p = 0.017), there was no significant difference in ischaemia time, anastomosis time or angiographic assessment between anastomotic techniques. Although operative time in group II was significantly shorter than in group I, this was likely due to the small sample size. There were no differences in anastomotic time or coronary occlusion time. There were also no significant differences in canine weight, IMA mobilization time, lipectomy/pericardiotomy, LAD identification, subxiphoid port placement, stabilizer position, or LAD dissection time between the cases performed with the conventional running suture and the cases performed with u-clips. Interrupted nitinol clip anastomosis or conventional running suture anastomoses are equally favourable in the short term when performing a TECAB procedure.

Prospective Evaluation of the St. Jude Medical Aortic Connector for Aortic-to-Autologous Vessel Graft Anastomoses

: Evolving technologies of proximal anastomosis devices meet the endeavor of surgeons to minimize manipulation of the ascending aorta during surgical myocardial revascularization. The objective of this study was to compare the patency rate of the saphenous vein coronary bypass grafts in which the proximal anastomoses were performed with automatic connector devices to the suture technique. : From September 2002 through July 2003, 86 patients underwent coronary artery bypass grafting with at least 1 vein graft anastomosed to the ascending aorta with the Symmetry G2 connector. Six-month clinical and angiographic follow-up, including Core-Lab quantitative coronary angiography (QCA) and corrected TIMI frame count (CTFC), was performed. : Eighty patients had at least 1 connector successfully implanted. Freedom from MACE (cardiac mortality myocardial infarction and target vessel reintervention) was 72/80 (90%). Six patients underwent a target vessel reintervention on the connector grafts. Six-month (mean 193 ± 36 days) angiography patency rates for the connector grafts were 72/81 (88.89%), 37/40 (92.5%) in sutured grafts, and 60/62 (96.8%) in arterial grafts. By QCA, 64/65 (98.5%) patent connector-grafts were free from more than 50% stenosis (1 connector-graft with a 51% stenosis). CTFC showed 65/65 (100%) patent connector-grafts with nonrestrictive flow. : Saphenous vein grafts anastomosed to the aorta with the Symmetry G2 connector have early and midterm patency rates comparable to the conventional sutured anastomoses. These results support the efficiency of the second generation of symmetry aortic connectors.

Laser-assisted vascular end to end anastomosis of elastin heterograft to carotid artery with an albumin stent: a preliminary in vivo study.

Laser-assisted end to end vascular anastomosis of an elastin heterograft to native artery may prevent problems associated with currently available vascular synthetic grafts and conventional suture anastomosis. A total of 21 anastomoses in the carotid arteries of 7 domestic swine were performed with an 800 nm laser and an albumin stent plus solder. There were 5 artery to artery and 16 elastin heterograft to native artery anastomoses. Operative parameters, vascular patency, and histology of the anastomoses were evaluated. Out of 21 anastomoses, 16 were patent for 3 hours. One artery to artery anastomosis was thrombosed and four elastin heterograft to artery anastomoses were excluded from the study due to heterograft burst. The average amount of applied energy was 212 J for artery to artery anastomosis and 273 J for elastin heterograft to native artery. Histology shows coagulative necrosis of the adventitia, hypereosinophilic contraction band in the media of native arteries and no changes in elastin heterografts. Laser-assisted vascular anastomosis (LAVA) of elastin heterograft to medium size vessel using an albumin stent is feasible. Chronic studies are warranted to determine long-term patency and histology of the LAVA.

Microvascular anastomosis using cyanoacrylate adhesives.

This paper describes a new technique for microvascular anastomosis, which involves the overlapping of the adventitias of the two ends of a severed blood vessel, and then painting a cyanoacrylate adhesive on the outer surface of the vessel around the anastomosed part. Sixteen anastomoses were performed in both radial arteries and cephalic veins in eight dogs. All vessels were patent without thrombus. The described method of anastomosis was faster and easier to perform than the conventional suture anastomosis. Histologic studies revealed that the adhesive did not flow into the lumen, and that normal healing of the endothelium and of the internal elastic lamina occurred across the anastomotic site, even though the adhesive remained on the adventitial side of the vessel at 4 weeks. This technique deserves to be considered as an alternative to conventional suture anastomosis.

Intestinal anastomoses detected with a photopolymerized hydrogel

Background. This study examines the efficacy of a novel, absorbable photopolymerized hydrogel sealant, Focalseal (Focal Inc, Lexington, Mass), in protecting high-risk suture deficient intestinal anastomoses (HRA) compared with conventional sutured anastomoses (CSA). Methods. Twenty-four New Zealand white rabbits were either randomized to small bowel HRA constructed with 4 interrupted 5/0 polyglyconate sutures and treated with Focalseal or small bowel CSA constructed with 8 to 10 interrupted 5/0 polyglyconate sutures. Four rabbits from each group were killed at postoperative days 3, 7, and 21. Anastomoses were assessed for evidence of dehiscence, adhesion formation, stenosis, and bursting pressure; they were also examined histologically for collagen content estimation and blood vessel formation. Results. Mean operative time was 35 minutes (SD 5) for CSA and 35 minutes (SD 5) for HRA. There was 1 postoperative death in the HRA group. A postmortem examination revealed no evidence of anastomotic leak. The remaining 23 animals were assessed as planned. There was no evidence of anastomotic dehiscence in any animal. There was no significant difference in adhesion formation (P =.09), stenosis (P =.6), or bursting pressure (P =.2) between HRA and CSA groups. Collagen (P =.007) and blood vessel (P =.002) formation were significantly increased in HRA. Conclusions. HRA treated with Focalseal heal well and have similar strength to CSA. This technique may prove valuable in procedures such as laparoscopic bowel resection. (Surgery 2002;131:185-9.)

Long-term effects of extraluminal dilatation with a rigid circle on arteriovenous anastomotic line in venous grafts transposed into arterial defects.

Postanastomotic narrowing resulting from subintimal hyperplasia is a well-known phenomenon. In the current study the authors compared a metallic circle and conventional suture technique in anastomoses performed in two ends of external jugular vein grafts interposed in carotid arteries of rabbits. They recorded the patency rates, fluid flow rates, and histological effects of the circle on the anastomotic line and compared them with conventional suture anastomoses. In 16 rabbits (experimental group) a standard suture was used in both ends of the jugular vein graft transposed to the carotid arteries on one side. On the other side, circle anastomoses were performed on both ends of the vein graft. In an additional 8 rabbits (control group), the anterior jugular veins and carotid arteries were dissected on both sides and left. During postoperative week 12, in 8 rabbits of the experimental group, the flow rates of carotid arteries were measured in vitro, and intraluminal silicone casts were prepared. In the remaining 8 experimental rabbits, carotid angiographies were performed and anastomotic segments were harvested for histological examination. Flow rates were also measured in the control group, and artery and vein segments were harvested. The patency rates of the vein grafts with metallic circle anastomoses were 100%, whereas conventional suture patency was 75% at week 12. Flow rates were significantly higher in the metallic circle-anastomosed vein grafts (74 ml per minute vs. 123 ml per minute, mean values; p < 0.05). Histological examination revealed reduced intimal thickness in the metallic circle anastomoses compared with conventional suture anastomoses. Dilatation of the arteriovenous end-to-end anastomotic line by a rigid circle prevents anastomotic narrowing in the long term.

Gastrointestinal Anastomosis With Histoacryl Glue in Rats

Technical difficulties in creating gastrointestinal anastomosis in infants and young children, because of the small lumen, are well known and may be complicated by a narrow passage, anastomotic obstruction, gastric stasis, recurrent vomiting, and failure to gain weight. The search for alternative easier technique was the basis for this study. The primary aim was to evaluate the safety of anastomosis between the stomach and a loop of the jejunum performed by using the tissue adhesive Histoacryl glue in comparison with the same anastomosis performed conventionally with absorbable sutures. We compared the results of gastrojejunal anastomosis in rats using either Histoacryl (n-butyl cyanoacrylate) glue or continuous, absorbable sutures. Sixty-four Sprague-Dawley rats were divided into 4 groups of 16 rats each. Gastroenterostomy was performed with either type of anastomosis with and without truncal vagotomy. The criteria of gastroenterostomy investigated included anastomotic leakage, stricture formation, adhesion formation, and histological examination. The pH of gastric secretion was measured with intact gastric innervation and after vagotmy in all rats. The time to complete each type of anastomosis was measured in minutes. Anastomotic stricture, leak, peritonitis, and death happened in three rats in each group with intact vagal innervation, in two rats after vagotomy and anastomosis with Histoacryl, and in one rat after vagotomy and anastomosis with sutures. The results showed no statistically significant differences between the various groups, except the shorter time for performing the glued anastomosis (5-7 min) compared to the conventional anastomosis (16-21 min). In conclusion, gastroenterostomy with Histoacryl in rats appears to be as safe as conventional suture anastomosis, saves operating time, and is not affected by gastric acidity.

Microvascular anastomoses using an Nd-YAG laser.

The authors performed anastomoses of small vessels with the Nd-YAG laser, comparing these with conventional suture anastomoses. Some arteries were sutured with 10-0 nylon with about eight suture sites, and others were held by stay sutures at three points with laser irradiation performed between them. Two surgeons performed the anastomoses in the same way. The first was well-trained and experienced, and the second was technically inexperienced. The authors evaluated clamping time, patency rate, and endoscopic and histologic findings. The patency rate of the first surgeon was 100 percent (30/30) in the suture anastomoses and was 97 percent (29/30) in the laser anastomoses. For the second surgeon, the rates were 60 percent (18/30) in the suture group and 80 percent (24/30) in the laser group. On histologic examination, the suture group showed inflammatory cells around the suture site at the fourth week after the operation. In the laser group, an inflammatory reaction around the suture material was observed, but the other areas recovered. For the experienced surgeon, the patency rate and clamping time of the laser anastomosis provided no statistically significant difference to those of the suture anastomosis. On the other hand, for the inexperienced surgeon, the patency rate of the laser anastomosis was superior to that of the suture anastomosis, and the clamping time of the laser anastomosis was shorter than that of the suture anastomosis. Therefore, the authors concluded that the Nd-YAG laser anastomosis is useful for small vessels.

Laser welding for vascular anastomosis using albumin solder: an approach for MID-CAB.

To improve minimally invasive direct coronary artery bypass surgery (MID-CAB), new techniques of vascular anastomosis that are faster and more reliable need to be developed. Common carotids in a canine model were transected and an end-to-end anastomosis was performed by using one of four techniques (1) continuous 6-0 polypropylene closure (suture; n=6), (2) vascular clip (VCS; n=6), laser welding using 50% albumin solder with (3) a 1.32-micro laser (1.32las; n=6), and (4) a 1.9-micro diode laser (1.9las; n=4). Times for anastomosis (TA) were compared between groups by t-test. Pressures at which anastomosis failed (leak point pressure, LPP) were determined and compared by analysis of variance. TA was faster for 1.32las and 1.9las at 8.4+/-0.7 and 7.8+/-0.3 min, respectively, when compared with suture at 13.8+/-1.0 min (P=0.001, confidence interval [CI]-8.1, -2.6 for 1.32las and CI -8.9, -3.1 for 1.9las). There was no statistical difference between VCS (8.3+/-3.3 min) and any other group (P > 0.17). LPPs (mm Hg) were similar for all groups: 350+/-37 for 1.32las, 280+/-31 for 1.9las, 347+/-46 for suture, and 358+/-53 for VCS, P=0.68. In this study, laser welding using 50% human albumin solder resulted in faster anastomotic times. Anastomoses were equivalent to conventional sutured anastomoses in failing at similar pressures. Laser welding using human albumin solder may be advantageous in improving coronary anastomoses during MID-CAB, but long-term anastomotic strength and histologic evaluation need to be investigated.

Laser welding for vascular anastomosis using albumin solder: An approach for MID‐CAB

Background and Objectives To improve minimally invasive direct coronary artery bypass surgery (MID-CAB), new techniques of vascular anastomosis that are faster and more reliable need to be developed. Study Design/Materials and Methods Common carotids in a canine model were transected and an end-to-end anastomosis was performed by using one of four techniques (1) continuous 6-0 polypropylene closure (suture; n = 6), (2) vascular clip (VCS; n = 6), laser welding using 50% albumin solder with (3) a 1.32-μ laser (1.32las; n = 6), and (4) a 1.9-μ diode laser (1.9las; n = 4). Times for anastomosis (TA) were compared between groups by t-test. Pressures at which anastomosis failed (leak point pressure, LPP) were determined and compared by analysis of variance. Results TA was faster for 1.32las and 1.9las at 8.4 ± 0.7 and 7.8 ± 0.3 min, respectively, when compared with suture at 13.8 ± 1.0 min ( P = 0.001, confidence interval [CI]−8.1, −2.6 for 1.32las and CI −8.9, −3.1 for 1.9las). There was no statistical difference between VCS (8.3 ± 3.3 min) and any other group (P > 0.17). LPPs (mm Hg) were similar for all groups: 350 ± 37 for 1.32las, 280 ± 31 for 1.9las, 347 ± 46 for suture, and 358 ± 53 for VCS, P = 0.68. Conclusions In this study, laser welding using 50% human albumin solder resulted in faster anastomotic times. Anastomoses were equivalent to conventional sutured anastomoses in failing at similar pressures. Laser welding using human albumin solder may be advantageous in improving coronary anastomoses during MID-CAB, but long-term anastomotic strength and histologic evaluation need to be investigated. Lasers Surg. Med. 24:264–268, 1999. © 1999 Wiley-Liss, Inc.

FIBRIN-GLUE ASSISTED VASOEPIDIDYMOSTOMY: A COMPARISON TO STANDARD END-TO-SIDE MICROSURGICAL VASOEPIDIDYMOSTOMY IN THE RAT MODEL

The use of fibrin glue for vasovasostomy has produced high patency rates in animal models. Vasoepididymostomy is a microsurgical technique that might be made easier if fibrin glue could substitute for microsutures. We evaluated the efficacy of a new vasoepididymostomy technique using fibrin glue. Bilateral vasoepididymostomies were performed in 24 male Sprague-Dawley rats using a conventional microsurgical technique on one side and a fibrin-glue assisted technique on the other. The rats were sacrificed 30 days after surgery and anastomotic patency was assessed by examining the vasal fluid for sperm, injecting methylene blue dye into the vas deferens and observing backflow into the epididymis by gross inspection and histological studies. Additionally, the incidence of granuloma formation was compared between the two techniques. Fibrin-glue anastomoses showed a patency rate of 79% (n = 19), compared with 63% (n = 15) for the conventional suture anastomoses (p = 0.29). Among the patent anastomoses, the incidence of sperm granuloma formation between the sutured (12, 50%) and the fibrin glue anastomoses (16, 67%) did not differ significantly (p = 0.36). Morphological tissue changes were similar for the two techniques. The time required for anastomosis using fibrin glue was significantly shorter than the conventional suture technique (p < 0.001). Conventional suturing techniques for vasoepididymostomy require advanced microsurgical skills. The use of fibrin glue simplifies this procedure and provides patency rates comparable to microsutured, end-to-side anastomoses.

Vessel-wall recovery after diode laser-assisted microvascular anastomosis: clinical and histologic analysis on long-term follow-up.

The authors recently reported an experimental study on diode laser-assisted microvascular anastomosis (LAMA) in the femoral arteries and veins of rats. Good success rates and very promising histologic results obtained in this preliminary phase suggested an extension of the investigation with a larger number of rats and for longer follow-up periods. In the present work, they describe an experimental study with two main goals: 1) improvements of the laser-assisted surgical procedure for reduction in the number of permanent stay sutures, with minimization of bleeding at the end of the intervention, compared with conventional microvascular sutured anastomosis (CMSA); and 2) providing more information on the repair mechanism(s) induced by laser treatment, obtained from clinical and histologic analyses extended up to 3 months of follow-up. In a total of 64 Wistar rats, 46 arterial and 22 venous LAMAs were performed, and 15 arterial and 11 venous CMSAs. The recorded success rates of LAMA in both arteries and veins were fairly high (67/68 at the time of surgery, and 54/55 in the follow-up), and substantially comparable with those of CMSA. Clear evidence of a superior healing process in the LAMAs was provided by histologic examinations. In particular, specific stains and immunohistochemistry analysis indicated that laser irradiation can induce wide proliferation of smooth muscle cells and negligible scar tissue which, together with diminished foreign-body reaction consequent to the reduction of suture material, result in a better restoration of vessel structures.

IMPLANTATION OF AN INTRALUMINAL RINGED PROSTHESIS IN HIGH-RISK PATIENTS WITH ACUTE AORTIC DISSECTION TYPE I

Surgical therapy for acute dissection of the ascending aorta has had a high mortality. The contributing factors have been hemorrhage from the suture lines and pulmonary dysfunction following a prolongation of extra corporeal circulation (ECC) time. A method of treatment with an intraluminal prosthesis that requires no end-to-end anastomosis has been developed. We have used this method in two patients, who had acute aortic dissections type I and high risks. The first case involved a patient of advanced age and had poor pulmonary function. The second case involved a patient with poor liver function and decreased blood platelet count. The sutureless fixations shortened ECC times which were 98 and 107 minutes in the first and second cases, respectively and reduced blood loss. There were neither hospital deaths nor early graft-related complications. Our experience with these cases suggests that grafting of the aorta is less hazardous with the sutureless than with the conventional sutured anastomosis technique in the high risk patients.

First experimental sutureless laser anastomosis of the large bowel

Large bowel anastomoses were successfully performed without sutures on New Zealand white rabbits using 1,064 nm, 0.4-W power pulsating Nd:YAG laser to create tissue welding. The aim of this study was to assess long-term results of our experimental data and summarize our experimental work on laser colon anastomosis. This experimental study investigated long-term integrity, degree of narrowing, animal body weight change, visual findings, microscopic appearance, and collagen concentration of laser colon anastomoses, compared with those of conventional sutured anastomoses at thirty and ninety postoperative days. Two animals in the laser group died without leakage. Postsurgical course in all remaining rabbits studied was uneventful. Bursting pressures in the two groups were equivalent, but the laser group exhibited a consistent narrowing tendency. However, laser anastomoses demonstrated fewer and milder adhesions, and animals showed a better recovery of body weight. Histologically, laser anastomoses showed better layer-to-layer reconstitution without foreign body response and with less fibrosis. Difference in collagen (hydroxyproline) concentration did not reach statistical significance. The nature of tissue welding via laser remains undefined, but there is definitely a future for laser bowel anastomosis.