Animal model to compare the effects of suture technique on cross-sectional compliance on end-to-side anastomoses

Continuous suture is a risk factor for benign hepaticojejunostomy stenosis after pancreatoduodenectomy in patients with a non-dilated bile duct

BACKGROUND

It is unclear whether hepaticojejunostomy with a continuous suture is suitable for patients with a non-dilated bile duct.

METHODS

Medical records of patients who underwent pancreatoduodenectomy between 2003 and 2013 were retrospectively reviewed, focusing on the incidence of benign anastomotic stenosis and its relationship with suture method (continuous vs interrupted) and common hepatic duct size.

RESULTS

Among 336 patients, 172 had a non-dilated (<8 mm) duct, and the remaining 164 had a dilated duct. Benign stenosis occurred in 12.2% (21/172) in the former, but in only 0.6% (1/164) in the latter (p < 0.001; median follow-up period, 43.5 months). Thus, further analysis was conducted in the 172 patients with a non-dilated duct, among whom 116 received a continuous suture and 56 received an interrupted suture. The cumulative incidence of benign anastomotic stenosis was significantly higher in patients who received a continuous suture vs those who received an interrupted suture (15.6% vs 1.8%, respectively, at 3 years; p = 0.006). Multivariable analysis identified continuous suture, male gender, and cholangitis (within 3 months after surgery) as independent risk factors for benign stenosis.

CONCLUSIONS

In this observational study, the use of a continuous suture was associated with benign anastomotic stricture in patients with a non-dilated hepatic duct.

The effect of bovine serum albumin-glutaraldehyde and polyethylene glycol polymer on neointimal hyperplasia in rabbit carotid artery anastomosis

OBJECTIVE

Since the systemic drugs have been used to reduce the hyperplasic response in the tunica intima, the periadventitial local drug applications to the vascular wall have gained more popularity. In this study, we investigated the effect of bovine serum albumin-glutaraldehyde and polyethylene glycol polymer on neointimal hyperplasia in rabbit carotid artery anastomosis to explore the effects of these two different agents.

METHODS

21 New Zealand male rabbits were randomly divided into three groups. The carotid artery transection and anastomosis was performed onthe control group. The bovine serum albumin-glutaraldehyde and the polyethylene glycol polymer were applied locally on the other two groups seperatley after transection and anastomosis of the carotid arteries. At the end of 28-day follow-up, the histological and the immunohistochemical results related to neointimal hyperplasia were compared.

RESULTS

The glue residues were detected in the BSA-glutaraldehyde group, but in the PEG polymer group there was no glue residue. The intima thickness and the intima/media thickness ratio in the control group was significantly higher (p<0.05) than the other groups. These values did not differ significantly between the BSA-glutaraldehyde group and the PEG polymer group (p>0.05). The lumen diameter and the area in the control group were significantly higher (p < 0.05) than the BSA-glutaraldehyde group. These values between the control group and the PEG polymer group did not differ significantly (p>0.05). aSMA-positive staining score in the Control group was found to be significantly lower (p < 0.05) than the BSA-glutaraldehyde and PEG polymer group and the VEGF-positive staining score in the control group was found to be significantly higher (p < 0.05) than the BSA-glutaraldehyde and the PEG polymer group.

CONCLUSIONS

Although the both agents have positive results on neointimal hyperplasia, it would be favorable to use polyethylene glycol polymer, since it does not seem to affect the lumen area and the lumen diameter of the vessel.

An alternative technique of arterial anastomosis in mouse heart transplantation

OBJECTIVE

To investigate the characters and feasibility of continuous-interrupted suture (CIS) method for arterial anastomosis in mouse heart transplantation (MHT).

METHODS

A MHT model was adopted. End-to-end anastomosis of donor ascending aorta to recipient abdominal aorta was achieved by CIS or continuous suture (CS) method. In both groups, end-to-end anastomosis of pulmonary vein to inferior vena cava (IVC) was achieved by CS. Technical indexes and histological examination were analyzed between 2 groups.

RESULTS

The total operative time in CIS group was 92.83 ± 2.13 minutes, and in CS group was 92.40 ± 3.85 minutes. In CS group, artery anastomosis time was 20.13 ± 1.89 minutes; in CIS group, it was 20.36 ± 1.09 minutes. Additionally, venous anastomosis time in CS group was 14.80 ± 0.84 minutes, and in CIS group was 15.03 ± 0.85 minutes. Operation success rate in CIS group was 100%, and in CS group was 80%. There were no significant histological findings differences in graft between 2 groups. However, cell arrangement of anastomosis site was lightly irregular and the vascular alignment was poor in CS group. In CIS group, cell arrangement of anastomosis site was well arranged and vessels were well aligned.

CONCLUSIONS

CIS method could avoid arterial anastomosis-related complications induced by CS and improve the success rate.

Creation of Native Arteriovenous Fistulas with Interrupted Anastomoses Using a Self-Closing Clip Device - One Clinic's Experience

The nitinol U-CLIP™ Anastomotic Device (Coalescent Surgical, Inc., Sunnyvale, CA) is a self-closing penetrating vascular clip that reduces suture management and eliminates knot tying, thus enabling rapid and precise interrupted suture placement and facilitating creation of an optimal vascular anastomosis. This report describes the use of U-CLIP devices in the surgical creation of native arteriovenous fistulas in 68 chronic hemodialysis patients. Overall, 61 of the 65 fistulas created matured successfully within 8–9 weeks. Radial cephalic fistulas: 93% were mature at 8 weeks. Brachiocephalic fistulas: 69% were mature at 8 weeks. One-stage basilic vein transposition: 100% were mature at 9 weeks. Two-stage basilic vein transposition: 100% were mature at 8 weeks after second stage. The results in this report show the excellent performance of U-CLIP vascular clips in the creation of several types of native arteriovenous fistulas in chronic hemodialysis patients. The fistulas created using the U-CLIP devices had a high maturation rate within a relatively short time period, and provided uniformly high flow rates. The patients in this study were a challenging population, with a high incidence of diabetes mellitus (81% of the patients) and vein sizes that were smaller than typically used for fistula creation. The U-CLIP™ Anastomotic Device offers the opportunity to create superior interrupted anastomoses for AV fistulas, even in patients who would otherwise be considered poor candidates for fistula creation.

Anastomotic Strategies to Improve Hemodialysis Access Patency—A Review

The number of patients with end-stage renal disease (ESRD) who require maintenance hemodialysis has risen sharply in the past 2 decades. It is estimated that more than 60% of all patients with ESRD who require chronic hemodialysis are accessed through an arteriovenous fistula (AVF) or graft (AVG), and the incidence is increasing at a rate of 2% to 4% per year. The long-term patency rate of an upper extremity AVF or AVG for hemodialysis access remains suboptimal owing in part to progressive stenosis at the venous anastomosis. This article reviews the causative factors of dialysis access-related anastomotic stenosis, or intimal hyperplasia. This article also reviews the clinical experience of various anastomotic strategies to ameliorate the hemodynamic environment in an effort to improve the clinical outcome of hemodialysis access. These strategies include the use of (1) vein cuff at the expanded polytetrafluoroethylene (ePTFE)-venous anastomosis of AVG, (2) cuffed ePTFE dialysis AVG, and (3) anastomotic devices that create an interrupted anastomosis with staples or clips.

Results with continuous cardiopulmonary bypass for the bidirectional cavopulmonary anastomosis

OBJECTIVE

Some centres have proposed creating the bidirectional cavopulmonary anastomosis without cardiopulmonary bypass, while others continue to use deep hypothermic circulatory arrest. The purpose of this review is to evaluate the results of using continuous cardiopulmonary bypass with moderate hypothermia, perhaps the most commonly used of the three techniques for this procedure.

METHODS

Between 1990 and 2005, 114 patients, having a mean age of 1.58 years, with a median age of 8 months, and ranging from 3 months to 16 years, underwent creation of either a unilateral cavopulmonary anastomosis, in 94 cases, or bilateral anastomoses in 20 cases. All had continuous cardiopulmonary bypass with moderate hypothermia at 32 degrees Celsius, with 24 also having aortic cross-clamping with cardioplegia for simultaneous intracardiac procedures. Interrupted absorbable sutures were used to create the anastomosis in 105 patients.

RESULTS

Perioperative mortality was 5%, with 6 of the patients dying. The mean period of cardiopulmonary bypass for an isolated anastomosis was 91 minutes, with a range from 44 to 160 minutes. In 10 patients (8.8%), it was necessary to place a graft to augment the anastomosis. The average postoperative length of stay was 7.9 days for those undergoing an isolated unilateral anastomosis, and 16.4 days for patients undergoing combined cardiac operations. We have now created the Fontan circulation in 79 of the patients, at an average interval from the bidirectional cavopulmonary anastomosis of 2.1 plus or minus 1.14 years. In 76 patients, we performed postoperative angiograms, and none revealed any stenoses.

CONCLUSIONS

The bidirectional cavopulmonary anastomosis can be performed successfully with continuous cardiopulmonary bypass and moderate hypothermia with a beating heart, avoiding circulatory arrest. The use of interrupted and absorbable sutures was not associated with any late anastomotic stenosis.

Application of a New Suture Material Called the U-Clip for Composite and Sequential Grafting with Off-Pump Coronary Bypass Surgery

BACKGROUND

The U-Clip was found to facilitate the interrupted anastomosis of coronary artery bypass grafts (CABG). This device may be beneficial especially in multivessel off-pump CABG (OPCAB) using composite grafts or sequential anastomosis. The aim of this study was to evaluate our early clinical experience using the U-Clip in OPCAB cases.

METHODS

This retrospective study included 118 patients who underwent off-pump CABG between 2001 and 2004. The mean age of the 91 men and 27 women was 69.5 +/- 8.0 years (range, 47-85). The U-Clip was adopted for sewing 73 proximal ends of the free graft to the side or end of the inflow conduit to prepare the composite graft. The U-Clip was also applied to 112 distal anastomoses, especially to the side-to-side anastomosis of the sequential graft.

RESULTS

Hospital mortality rate was 0.8% (1/118). The early patency rate of distal anastomoses using the U-Clip was 95% (96/101). The early patency rate of proximal anastomoses using the U-Clip was 98.4% (62/63). Interim angiography was performed in 12 patients (range, 3.8-42 months; average, 16 months). In these 12 patients, a total of 8 proximal anastomoses of conduits using the U-Clip were all patent without stenosis. The patency rate of a total of 10 distal anastomoses in the 12 patients using the U-Clip was 100%.

CONCLUSIONS

The U-Clip-interrupted anastomosis enables a safe, definite, and rapid end-to-end or end-to-side connection of arterial grafts. We therefore consider the U-Clip to be a useful suture material especially for multivessel OPCAB using multiple arterial grafts.

Experimental study of one-shot vascular anastomostic device for proximal vein graft anastomoses

PURPOSE

A new type of sutureless aortic-vein-graft vascular anastomostic device, One-Shot Vascular Anastomostic Device (Horologe Factory of Jinan City, Shandong Province, China) has been recently designed to create a one-shot anastomosis between the aorta and vein grafts for coronary artery bypass grafting surgery.

DESCRIPTION

Twelve pigs were scheduled for the test of the feasibility of the One-Shot Vascular Anastomostic Device for artery to vein graft anastomosis. In each animal one proximal anastomosis was performed by means of the One-Shot Vascular Anastomostic Device and the distal end was sutured in a conventional manner to serve as the animal own control. The anastomosis incorporating the abdominal main artery to the segment of a free external carotid vein to the external iliac artery is for the simulation of the aorta-vein anastomosis.

EVALUATION

The mean duration of the completion of the proximal anastomosis was 1.2 +/- 1.2 minutes (range, 0.3-5.0 minutes). There was a significant difference between the control groups (p < 0.01). All vein grafts were still functioning at the end of the procedure. Pathologic studies and angiography demonstrated that the results were satisfactory.

CONCLUSIONS

This device enables rapid and safe completion of vascular anastomostic procedure. The vein graft was functioning well and incorporated into the vessel intima smoothly.

S2 connector versus suture: distal coronary anastomosis remodeling, patency, and function in the pig

BACKGROUND

Anastomotic connectors could be the key to less invasive bypass surgery, including endoscopic procedures, but equivalence to conventional suturing needs to be established. A novel distal coronary connector was tested pre-clinically for safety and efficacy in comparison to conventional suturing.

METHODS AND RESULTS

Left internal thoracic to left anterior descending coronary artery bypasses were constructed off-pump in 35 pigs (73+/-8 kg). An intraluminal metal connector (S2AS) was used in 21 and conventional suturing in 14 animals. S2AS anastomosis construction was easier achieved in one-fourth of the conventional construction time (3.7+/-0.7 versus 16.5+/-2.6 minutes; P<0.001). Acute patency tended to be better (P=0.15). All anastomoses were evaluated intraoperatively, and subgroups at 90 and at 180 days. Patency was 100%. An effective remodeling response was observed in all groups, resulting in unobstructed anastomoses with excellent hemodynamic performance (fractional flow reserve > or = 0.93 at 180 days). At 6 months, the noncompliant connector was covered with stabilized neointima that was thinner than found on the suture line (0.10+/-0.04 versus 0.31+/-0.13 mm; P=0.01). The connector induced less lumen loss (-0.6+/-6.5 versus 21.6+/-19%; P=0.03). The initial side-to-side configuration had remodeled to an end-to-side shape as intended.

CONCLUSIONS

In the porcine model, the connector rapidly and consistently produced high-quality anastomoses that fully met current standards on patency and function. Unconventional aspects like a noncompliant intraluminal ring and a side-to-side to end-to-side converted configuration did not interfere with favorable anastomosis remodeling. These findings shed a new light on the anatomical prerequisites for anastomosis patency.

Experimental comparison of four methods of end-to-side anastomosis with expanded polytetrafluoroethylene

Background

Four established techniques of distal end-to-side anastomosis (direct anastomosis, Linton patch, Taylor patch and Miller cuff) were compared to investigate the local distribution of anastomotic intimal hyperplasia. The study aimed to elucidate whether mechanical factors or flow alterations are mainly responsible for the improved patency rates reported for vein cuff interposition techniques in infrainguinal arterial reconstructions using prosthetic graft material.

Methods

Thirty-two expanded polytetrafluoroethylene (ePTFE) femoropopliteal bypass grafts were implanted in 16 sheep using the four anastomotic techniques. After 6 months the grafts were explanted and examined histologically. The local distribution of intimal hyperplasia was determined, particularly for areas of material transition and of high and low shear stress.

Results

The mean amount and distribution of intimal hyperplasia were similar for all anastomotic types. Intimal hyperplasia was greatest along all transitions between ePTFE and venous patches, and between ePTFE and recipient artery. It was lower along the transitions between venous patches and artery, and was lowest at the host artery floor.

Conclusion

Vein interposition did not reduce anastomotic intimal hyperplasia and did not change the distribution patterns of hyperplasia, which were influenced mainly by mechanical factors. The effect of vein interposition is to move areas of maximum intimal hyperplasia away from the small recipient artery up to the more capacious graft-patch anastomosis.

A prospective evaluation of interrupted nitinol surgical clips in arteriovenous fistula for hemodialysis

BACKGROUND

The use of a self-closing nitinol surgical clip (Coalescent Surgical U-Clip) is a novel technique of creating an interrupted vascular anastomosis, which also eliminates the knot tying associated with a conventional vascular anastomosis. The purpose of this study was to compare the clinical outcome of arteriovenous fistulae (AVF) for hemodialysis as constructed using interrupted U-Clip devices and conventional continuous polypropylene sutures.

METHODS

We prospectively studied the clinical course of 132 patients (149 access) undergoing either forearm autologous arteriovenous fistula (FAVF, n = 69) or upper arm autologous arteriovenous fistula (UAVF, n = 80) or creations during a 39-month period. Among the FAVF, U-Clips and polypropylene sutures were used in 37 and 32 anastomoses, respectively. Among the UAVF, U-Clips and polypropylene sutures were used in 41 and 30 anastomoses, respectively. Primary patency, complication, and maturation rates were analyzed.

RESULTS

Clipped FAVF had an improved maturation rate at 6 weeks (32 of 37, 86%) when compared with sutured FAVF (22 of 32, 69%, P <0.05). There was no difference in the maturation rate among UAVF constructed with either U-Clips or sutures (88% versus 87%, not significant). The primary patency rates at 12, 24, and 36 months were 91%, 84%, and 75% for the clipped FAVF; and 83%, 74%, and 61% for the sutured FAVF (P <0.05) There was no difference in the patency rate of UAVF constructed with either U-Clips or polypropylene sutures at either 12, 24 or 36 moths (91%, 80%, and 75% versus 83%, 77%, and 69%, respectively).

CONCLUSIONS

The U-Clips are a viable alternative to sutures for creating vascular anastomosis. It provides a improved maturation and patency rates when compared with the conventional sutured AVF in the forearm. The clinical benefit of the U-Clips may be due in part to the improved compliance created by the interrupted anastomotic technique.

Improving the patency of vascular bypass grafts: the role of suture materials and surgical techniques on reducing anastomotic compliance mismatch

BACKGROUND

compliance mismatch is an important factor in the development of myointimal hyperplasia in both coronary and vascular anastomoses. This mismatch may be reduced by the use of newer suture materials and techniques. This review discusses the current techniques and materials used to date in generating anastomoses in both coronary and vascular applications and to correlate these with the degree of inherent compliance achieved.

METHODS

PubMed, ISIS, CAS and PAS database searches were performed. Other articles were cross-referenced.

RESULTS AND CONCLUSION

continuous suture is still the most used technique in both cardiac and vascular surgery for the generation of anastomoses due to the reduced time and improved haemostasis. However, continuous suture results in a greater compliance mismatch than the interrupted technique. Vein cuffs and patches improve compliance and transmission of pulsatile blood flow and offer improvement of graft patency. Alternative to sutures are biological glue, clips and laser generated solders all of which have shown promising results, but further work is required before they become applicable for routine use.