Numerical Simulation of Thrombus Formation after Artery Bypass Grafting with Distal-End Side-to-Side Anastomosis / 医用生物力学

Objective To study the difference in thrombus formation at distal end of the graft with two different treatments.Methods For coronary artery bypass grafting with distal-end side-to-side anastomosis (DESSA), two models with or without distal end trimming of the graft were established. Using the blood substance transport and diffusion model considering biochemical reactions, combined with hemodynamics parameters of shear rate, fluid residence time, and platelet distribution, the possibility of thrombus formation was evaluated. Numerical simulation method was used to investigate thrombus growth in coronary artery bypass grafting with DESSA.ResultsFor the model without distal end trimming of the graft, the thrombus was first formed on inner wall at distal end of the graft, and then grew inward until the thrombus occupied most of the graft region at distal end, which indicated that thrombus formation was in a stable state, and the volume of the thrombus didn’t change, the final volume of the thrombus was 15.05 mm3. For the model with distal end trimming of the graft, the final volume of the thrombus was 7.35 mm3, which was 51.2% smaller than that of the model without distal end trimming of the graft. Thrombus was formed on inner wall of the graft above the anastomosis for the model with distal end trimming of the graft, and the wall thickness was about 0.16 mm, which was 10.65% of the graft radius (1.50 mm). In the above two procedures, multiple vortices (blood flow velocity less than 10 mm/s) were formed in distal region of the graft, which further promoted thrombus formation at distal end of the graft. The area of thrombus formation obtained from numerical simulation was consistent with clinical investigation.Conclusions For clinical coronary artery bypass grafting with DESSA, the volume of the generated thrombus can be reduced for the model with distal end trimming of the graft. However, the effect of thrombus formation on inner wall of the graft above the anastomosis on coronary artery bypass grafting needs further study.

Side-to-side esophagojejunostomy after 4K laparoscopic total gastrectomy / 中华消化外科杂志

Digestive tract reconstruction with side-to-side esophagojejunostomy is one of the most commonly used digestive tract reconstruction methods after laparoscopic total gastrectomy. It does not need an auxiliary incision. The linear stapler is used to directly enter the abdominal cavity through the Trocar to perform side-to-side anastomosis of esophagojejunostomy. The common hole can be closed by hand suture or linear stapler. 4K laparoscopy can present a clearer and more realistic view to the operators, so as to realize side-to-side esophagojejunostomy more accurately, to reduce the postoperative anastomo-tic related complications and improve the safety of the operation. This article will elaborate the technical key points and difficulties of esophagojejunostomy in 4K laparoscopic total gastrectomy, as well as the prevention and treatment of anastomotic related complications.

Comprehensive training of rat abdominal aorta and common iliac artery for neurosurgical microvascular anastomosis / 中国脑血管病杂志

Objective To establish an animal model suitable for neurosurgeons for the comprehensive training of microvascular anastomosis using rat abdominal aorta and common iliac artery. Methods Twelve adult SD rats were selected,they were generally anesthetized and laparotomized.The abdominal aortas and bilateral common iliac arteries were exposed and fully separated.The lengths and diameters of abdominal aortas and common iliac arteries of each segment were measured.The end-to-end anastomosis were performed choosing the main trunk of the abdominal aorta without a branching artery and longer segment.The unilateral common iliac artery and the sacral median artery were used for end-to-side anastomosis.The bilateral common iliac arteries were used for end-to-side and side-to-side anastomosis.The micro Doppler ultrasound probe was used to detect the blood flow patency of each anastomotic stoma. Results Anatomical separation of the abdominal aortas and the common iliac arteries was successfully performed in 12 SD rats.Each rat could provide 4 vascular anastomosis exercises.The length of abdomen aorta trunk was 15.6 ± 2.5 mm and the diameter was 1.6 ±0.2 mm between the lower left renal artery and right iliolumbar artery.The side-to-side anastomosis was performed.The mean diameter of the median sacral arteries was 0.80 ±0.08 mm.After the fish mouth-like cutting,the end-to-side anastomosis of the right common iliac arteries were conducted.The lenth of left common iliac artery was 9.0 ± 1.5 mm,the diameter was 1.0 ± 0.1 mm,and was cut off at its origin and then the end-to-side anastomosis of the right common iliac arteries were conducted.After end-to-side anastomosis of bilateral common iliac arteries,its distal segment was arranged in parallel with a length of 5.1 ± 0.3 mm,and then the side-to-side anastomosis could be conducted. Conclusions The rat abdominal aorta and iliac artery model can be comprehensively used to simulate the commonly used neurosurgery bypass graft.It is suitable for neurosurgeons with a certain microsurgical basis to conduct a preliminary vascular anastomosis training.

Conquest of the Weak Point of the Side-to-side Anastomosis: The Novel Technique that Can Reinforce a Weak Point with Stapling.

Introduction: The improvement of stapling devices has been remarkable. As the stapler evolved from two lines to three lines of staples, the lateral strength of the anastomosis increased. However, the strength of the crotch did not change and the crotch remains the weak point of the side-to-side anastomosis. We previously reported the weakness of the crotch and the reinforcement method with animal model [1,2]. Technique: We describe our novel technique to reinforce the crotch using a physician-modified stapling device. A stapler with three rows of staples per side is arranged on a 6 cm segment using an EndoGIA Reinforce. Polymer felt is attached to both the cartridge fork and anvil fork of the stapler. The felt is then trimmed, as a length of 2 cm is sufficient for reinforcement of the crotch. Results: With this method, we can reinforce the weak point of the side-to-side anastomosis at the same time as the anastomosis. Conclusions: This method is a simple and novel technique to reinforce the crotch of a side-to-side anastomosis.

Bowel Anastomosis in Single Port Laparoscopic Right Hemicolectomy: Comparison of Functional End to End Anastomosis and Isoperistaltic Side to Side Anastomosis

PURPOSE: Colorectal surgeries by single port laparoscopic surgery (SPLS) are increasing. While recent studies have reported results that are similar with the idea of conventional laparoscopy, SPLS is considered superior to conventional laparoscopy with regard to cosmetic aspects. We investigated the question of whether length of incision and postoperative recovery are different depending on the method of anastomosis in patients who underw ent SPLS right hemicolectomy (RHC). METHODS: Data on patients who underwent SPLS RHC from May 2011 to April 2012 at Samsung Medical Center were retrospectively collected. Among 117 patients, 31 received functional end-to-end anastomosis (FEEA) while 86 received isoperistaltic side-to-side anastomosis (ISSA). RESULTS: Operation time was shorter in FEEA compared to ISSA (152+/-42 vs 172+/-35 min, p=0.01). Neither group required an additional port. Although wound extension for specimen delivery tended to be frequent in loop type specimen after FEEA, the result was statistically insignificant (58.1 vs 43.0%, p=0.15). No difference in wound length was observed (4.4+/-1.0 vs 4.5+/-1.5 cm). Length of stay was longer in ISSA compared to FEEA (6.3+/-2.1 vs 7.9+/-4.3 days, p=0.01), and there was no difference in first gas passage (2.5+/-0.9 vs 2.8+/-0.9 days, p=0.26). Although three patients (9.7%) with FEEA and 19 patients (22.1%) with ISSA had postoperative complications, the difference was insignificant. CONCLUSION: Theoretically, delivery of a tube shaped specimen after ISSA is expected to reduce unnecessary wound extension and possible tumor dissemination compared to loop shape specimen after FEEA. However, results of our study showed no advantage in recovery period and wound length. We suggest that future prospective study might reveal more valuable conclusions on the subject.

Clinical Analysis of Radiocephalic Fistula Using Side-to-side Anastomosis with Distal Cephalic Vein Ligation

BACKGROUND: The surgically created arteriovenous fistula has recently been recommended as the best available angioaccess for hemodialysis. Therefore, in this study, we carried out a clinical analysis on surgical procedures in the ligation and division of a distal vein to achieve similar effects as those of vein end-to-arterial side after side-to-side anastomosis. METHODS: We retrospectively reviewed the clinical data of 113 patients who came for an outpatient clinic follow-up to the department of internal medicine of our hospital; these patients were among the 125 patients who underwent radiocephalic arteriovenous fistula (side-to-side anastomosis with distal vein ligation and division) in our hospital in the period from January 2006 to December 2010. RESULTS: The patency rate showed no statistical significance with respect to sex (p=0.775), age (p=0.775), hypertension (p=0.262), diabetes (p=0.929), and cardio-neurovascular disease (p=0.717). Patency rates were 96% for the first month, 93% for the first year, and 90% for the second year for the radiocephalic arteriovenous fistula (side-to-side anastomosis with distal vein ligation and division) performed on the wrist. CONCLUSION: The patency rates revealed favorable results and few postoperative complications as compared to those of previous reports. Therefore, radiocephalic fistula using side-to-side anastomosis with distal cephalic vein ligation is considered a recommendable surgical procedure in the distal part for the hemodialysis of CRF patients.

Classification of microvascular anastomosis in oral and maxillofacial reconstruction

A reconstruction following a resection of malignant oral cavity tumors is one of the most difficult problems in recent oral oncology. For a better understanding of oral and maxillofacial reconstructive procedures, basic and advanced microvascular anastomosis techniques must be learned and memorized. The aim of this article was to clarify and define the microvascular anastomosis methods, such as primary closure after an arteriotomy, end to side anastomosis, end to end anastomosis, and side to side anastomosis with an artery and vein. This review article discusses the basic skills regarding microvascular anastomoses with brief schematic diagrams in the Korean language. This article is expected to be helpful, particularly to young doctors in the course of the Korean national board curriculum periods for oral and maxillofacial surgery.

Esophagectomy and cervical side-to-side stapled esophagogastric anastomosis / 中南大学学报(医学版)

ObjectiveTo determine the clinical effect and the prospect of cervical side-to-side stapled esophagogastric anastomosis. MethodsEighteen cases of upper and middle thoracic esophageal carcinoma were treated with esophagectomy and cervical side-to-side stapled esophagogastric anastomosis. The clinical data were collected and retrospectively analyzed. The average age of patients was 60.7 years and the ratio of male to female was 17∶1. The tumor included 4 upper part and 14 middle thoracic parts. The length of tumors was from 1 cm to 7 cm, with an average of 3.2 cm.ResultsThe post-operative TNM staging(AJCC) included 4 Stage Ⅱa,9 Stage Ⅱb,and 5 Stage Ⅲ. The operative incisions included 8 nontransthoracic cervical and abdominal double incisions, 9 right cervico-thoraco-abdominal triple incisions, and 1 left cervico-thoracic incision. One (5.56%) patient complicated with anastomotic leakage and was cured in 2 weeks by cervical drainage and absolute diet. All the 18 patients were followed up for 1 to 5 years,and no anastomotic stricture was found. Reflux esophagitis was found in 2 and the incidence rate was 11.11%.ConclusionCervical side-to-side esophagogastric anastomosis is a safe procedure with larger resection of margins and fewer complications. It is worth replicating.