Training model for end‐to‐side microvascular anastomosis in rat

End‐to‐side microsurgery is technically more challenging than end‐to‐end microvascular anastomosis. However, there is no ideal model to practice this exercise. An animal training model is described for practising this type of anastomosis.     

Effects of acetylo‐L‐carnitine in end‐to‐side neurorrhaphy: A pilot study

Purpose: End‐to‐side (ETS) nerve repair allows for target‐muscle reinnervation, with simultaneous preservation of donor‐nerve function. Acetyl‐L‐carnitine (ALCAR) was shown to enhance axonal sprouting in early regeneration following transection and repair of the sciatic nerve in rodents. The purpose of this article was to determine the ability of ALCAR to enhance axonal regeneration in an ETS rodent model. Method: The right musculocutaneous nerve in 16 adult male Sprague‐Dawley rats was transected to induce biceps muscle paralysis. The distal stump was then coapted by ETS neurorrhaphy through a perineurial window to the ipsilateral median nerve. Experimental groups received ALCAR for 1, 2, 3, and 4 weeks whereas controls received placebo. Results: Weekly postoperative behavioral evaluations revealed increased functional return over control but the difference was not significant. Potentials from biceps were recorded from the third postoperative week in the experimental group and from the fourth week in the control group. Histomorphometric evaluations revealed higher musculocutaneous nerve axon counts, higher myelin thickness in the fourth postoperative week, and differences in the appearance and the number of motor‐end‐plates in the biceps in experimental versus control group. Conclusion: Intraperitoneal administration of ALCAR can expedite biceps muscle recovery in an ETS model by increasing the rate of axonal regeneration. Despite the morphological changes, no behavioral changes were noted and further studies are needed to confirm clinical efficacy of ALCAR for potential use in the development of therapeutic protocols. © 2009 Wiley‐Liss, Inc. Microsurgery, 2009.     

A modified side‐to‐end lymphaticovenular anastomosis

Background:

Lymphaticovenular anastomosis (LVA) is a useful treatment for compression‐refractory lymphedema with its effectiveness and minimal invasiveness. However, LVA requires supermicrosurgery, where lymphatic vessels with a diameter of 0.5 mm or smaller are anastomosed using 11‐0 or 12‐0 suture. To make LVA easier and safer, we adopted a modified side‐to‐end (S‐E) anastomosis in LVA surgery.

Methods:

We performed modified S‐E LVAs in 14 limbs of female patients with lower extremity lymphedema (LEL). In modified S‐E LVA, lateral windows with a length of 1.0 mm or longer were created on a lymphatic vessel and a vein, respectively, and side‐to‐side (S‐S) anastomosis was established with 10‐0 continuous suture. After completion of S‐S anastomosis, the vein distal to the anastomosis site was ligated to prevent venous backflow and subsequent thrombosis at the anastomosis site. Lymphedematous volume was evaluated preoperatively and at postoperative 6 months using LEL index.

Results:

All the 24 modified S‐E anastomoses could be completed without difficulty or revision for anastomosis, and showed good patency after completion of anastomosis. Postoperatively, LEL indices significantly decreased compared with preoperative LEL index (255.9 ± 14.1 vs. 274.9 ± 22.2, P < 0.001).

Conclusions:

Modified S‐E LVA can efficaciously divert lymph flows into venous circulation without performing supermicrosurgical anastomosis. © 2012 Wiley Periodicals, Inc., Microsurgery, 2013.     

Long‐term follow up of abdominal rectosigmoidectomy with posterior end‐to‐side stapled anastomosis for Chagas megacolon

Aim Chagas’ disease is an endemic parasitosis found in Latin America. The disease affects different organs, such as heart, oesophagus, colon and rectum. Megacolon is the most frequent long‐term complication, caused by damage to the myoenteric and submucous plexus, ultimately leading to a functional barrier to the faeces. Patients with severe constipation are managed surgically. The study aimed to analyse the 10‐year minimum functional outcome after rectosigmoidectomy with posterior end‐to‐side anastomosis (RPESA). Method A total of 21 of 46 patients were available for follow up. Patients underwent clinical, radiological and manometric evaluation, and the results were compared with preoperative parameters. Results Of the 21 patients evaluated, 81% (17) were female, with a mean age of 60.6 years. Good function was achieved in all patients, with significant improvement in defaecatory frequency (P < 0.0001), usage of enemas (P < 0.0001) and patient satisfaction. Barium enema also showed resolution of the colonic and rectal dilatation in 19 cases evaluated postoperatively. Conclusion Minimal 10‐year follow up of RPESA showed excellent functional results, with no recurrence of constipation.     

Transrectal specimen extraction after laparoscopic left colectomy: a case‐matched study

Aim Avoiding ‘mini‐laparotomy’ to extract a colectomy specimen may decrease wound complications and further improve recovery after laparoscopic surgery. The aim of this study was to develop a new technique for transrectal specimen extraction (TRSE) and to compare it with conventional laparoscopy (CL) for left sided colectomy. Method Eleven patients with benign disease requiring either sigmoid or left colon resection underwent TRSE. The unfired circular stapler was inserted transanally and used as a guide to suture‐close the recto‐sigmoid junction laparoscopically and as a handle to pull the sutured sigmoid through the opened rectum inside a laparoscopic camera bag. The anvil was inserted into the lumen of the intussuscepted sigmoid and pushed to the level of the anastomosis. The anastomosis was fashioned end‐to‐end in the first patients and side‐to‐end in the following patients to improve safety. Intra‐operative and postoperative outcomes of patients undergoing TRSE were compared with those of a group of 20 patients undergoing CL, who were matched for type of resection, body mass index and age. Results The procedure was successful in all but the first patient who was converted to conventional laparoscopic colectomy without any additional morbidity. Two patients in the end‐to‐end anastomosis group, but none in the side‐to‐end group, developed peri‐anastomotic sepsis. Compared with CL, patients undergoing TRSE did not show any significant differences in operative time, recovery or morbidity. Conclusion Transrectal specimen extraction after left colectomy using the circular stapler technique is feasible. A side‐to‐end anastomosis appears safer than an end‐to‐end anastomosis. Further studies are needed to explore the potential advantages of this procedure over CL.     

J‐pouch vs side‐to‐end coloanal anastomosis after preoperative radiotherapy and total mesorectal excision for rectal cancer: a multicentre randomized trial

Aim Comparison of functional and surgical outcome of the J‐pouch with the side‐to‐end coloanal anastomosis after preoperative radiotherapy and total mesorectal excision in rectal cancer patients. Method In a multicentre study, patients with a carcinoma of the lower two‐thirds of the rectum were randomized to either a J‐pouch or a side‐to‐end reconstruction. Primary outcome was function of the neorectum 1 year after surgery. A functional outcome [COloREctal Functional Outcome (COREFO)] questionnaire, and two quality of life questionnaires (EORTC‐QLQ‐CR38 and SF‐36) were to be completed by all participants preoperatively, and 4 and 12 months postoperatively. Independent data managers recorded surgical outcome. A group size of 30 patients in each group was calculated based on a 15‐point difference of the COREFO scale. Results In total, 107 patients were randomized, 55 in the J‐pouch group and 52 in the side‐to‐end anastomosis group. The COREFO incontinence scale at 4 months and the total functional outcome at 4 and 12 months showed better results for the J‐pouch group in comparison with the side‐to‐end anastomosis group. The remaining COREFO scales (frequency, social impact, stool‐related aspects and bowel medication), surgical outcome (complications, reoperations, length of hospital stay, readmissions and mortality) and quality of life did not show significant differences between treatment groups. Conclusion The overall results of a coloanal J‐pouch and a side‐to‐end anastomosis are comparable, although functional results are slightly better with a J‐pouch. The side‐to‐end anastomosis is technically less demanding and therefore a justified alternative in sphincter‐saving surgery.     

Development of techniques for gastrojejunal bypass surgery in obese mice

We have previously described a duodenojejunal bypass (DJB) surgical model in healthy C57BL/6 mice. However, our pilot study showed that the same surgical technique caused a high mortality rate in obese mice. In this study, to significantly improve animal survival rate following bariatric surgery and thereby providing a stable surgical model for the study of glucose homeostasis in obese mice, we have used modified techniques and developed the end‐to‐side gastrojejunal bypass (GJB) surgery in obese C57BL/6 with impaired glucose tolerance. The modification consisted of using the distal part of the jejunum for biliopancreatic diversion including: 1) ligation of the distal stomach at the level of the pylorus; 2) connection the jejunum to the anterior wall of stomach in an end‐to‐side fashion; and 3) diverting the biliopancreatic secretions through the blind limb into the distal jejunum through an end‐to‐side anastomosis. We found that by modifying the proximal end‐to‐end duodenojejunal anastomosis, described in our original model, to an end‐to‐side gastrojejunal anastomosis in these obese mice, we were able to significantly improve the postoperative mortality in this study. We have also demonstrated that performing the GJB surgery in obese mice resulted in significant weight loss, normalized blood glucose levels, and prevented acute pancreatitis. This newly developed GJB surgery in the obese mice offers a unique advantage to study the mechanisms of gastrointestinal surgery as treatment for type 2 diabetes. © 2010 Wiley‐Liss, Inc. Microsurgery, 2010.     

Changes of the donor nerve in end‐to‐side neurorrhaphies with epineurial window and partial neurectomy: A long‐term evaluation in the rat model

End‐to‐side (ETS) neurorrhaphy has been applied in the repair of peripheral nerve injuries and in babysitter procedures. However, the long‐term changes of donor nerve and muscle after ETS remain unknown. This study was designed to investigate long‐term changes in donor nerve and muscle in a rat model. Sixty Lewis rats were equally allocated into three groups of 20 rats. The peroneal nerve was divided. In Group A, end‐to‐end (ETE) neurorrhaphy was performed. In Group B, ETS was performed to an epineurial window on the tibial nerve. In Group C, ETS was performed to the tibial nerve with 40% partial neurectomy. The following data were obtained at 6, 12, 18, and 24 weeks postoperatively: latency delaying rate (LDR), amplitude recovery rate (ARR), myelinated fiber counts, muscle force and weight, and cross‐sectional area of gastrocnemius muscle fibers. The results showed no significant changes of the donor nerve and muscle in Group B. Nerve regeneration was found in the peroneal nerve, and myelinated fiber number was significantly decreased when compared to the nerve with ETE. In Group C, the myelinated axon number in the peroneal nerve was equivalent to the level in ETE repair. However, function and structure of the donor nerve and muscle were significantly impaired in the early postoperative period. Nonetheless, full recovery was observed 24 weeks after surgery. Both ETS with epineurial window and 40% donor nerve neurectomy showed reinnervation of the recipient nerve without structural and functional changes of the donor system in a long‐term follow‐up. Partial neurectomy may promote recipient nerve regeneration, but at the cost of donor neuromuscular compromises in the early postoperative period. This study provides long‐term evidence for further investigation of ETS in peripheral nerve repair and in babysitter procedures. © 2013 Wiley Periodicals, Inc. Microsurgery 34:136–144, 2014.     

Patency rates in end to side anastomoses in the rabbit.

It is suggested that more widespread use of the end to side microvascular suturing technique should be made, especially in arteries. A simple experimental practice model in the rabbit is suggested. Patency rates comparable to end to end anastomosis can be achieved.     

Ladder‐shaped lymphaticovenular anastomosis using multiple side‐to‐side lymphatic anastomoses for a leg lymphedema patient

Lymphatic supermicrosurgery, supermicrosurgical lymphaticovenular anastomosis (LVA), is becoming a useful option for the treatment of compression‐refractory lymphedema. One of the most important points in LVA is to make as many bypasses as possible for better treatment results. We report a progressive lower extremity lymphedema (LEL) case successfully treated with a ladder‐shaped LVA. A 67‐year‐old female with secondary LEL refractory to conservative treatments underwent LVA. A ladder‐shaped LVA was performed at the left ankle. In the ladder‐shaped LVA, 3 lymphatic vessels and 1 vein were anastomosed in a side‐to‐side fashion; 2 lymphatic vessels next to the vein were anastomosed to the vein, and the other lymphatic vessel was anastomosed to the nearby lymphatic vessel. Using ladder‐shaped LVA, 6 lymph flows of 3 lymphatic vessels could be bypassed into a vein. Six months after the LVA operation, her left LEL index decreased from 212 to 195, indicating edematous volume reduction. Ladder‐shaped LVA may be a useful option when there are 3 lymphatic vessels and 1 vein in a surgical field. © 2013 Wiley Periodicals, Inc. Microsurgery 34:404–408, 2014.     

Effect of low‐thermal dissection device versus conventional electrocautery in mastectomy for female‐to‐male transgender patients

Subcutaneous mastectomy, the first step in sexual reassignment surgery of female‐to‐male transsexuals, is associated with high rates of complication and revision surgery. Also, conventional electrosurgery and the associated thermal tissue damage may compromise outcome. This retrospective randomised clinical study evaluated the effect of low‐thermal plasma dissection device (PEAK PlasmaBlade, Medtronic, Minneapolis, Minnesota) in comparison with conventional electrosurgery. A total of 17 female‐to‐male transsexuals undergoing mastectomy were randomised to PEAK PlasmaBlade on one breast side and to monopolar electrosurgery on the other side of the same patient. Wounds of 17 patients were examined histologically for acute thermal injury. Significantly less total volume of drain output (58.8 ± 37.4 mL vs 98.5 ± 76.4 mL; P = .012) was found on the PEAK PlasmaBlade side compared with the electrosurgery side. Duration of drain was significantly shorter on the PEAK PlasmaBlade side (2.5 ± 0.7 days vs 3.2 ± 0.6 days; P = .010). Furthermore, the PEAK PlasmaBlade side showed fewer thermal damages (41.2% vs 82.4%; P = .039) and thermal injury depth from PEAK PlasmaBlade side was less (3170 vs 4060 μm). PEAK PlasmaBlade appears to be superior to monopolar electrosurgery for mastectomy in female‐to‐male transsexuals, because it demonstrated less thermal tissue damage, less total volume of drain output, and shorter duration of drain, resulting in faster wound healing.     

Does a previous end‐to‐end urethroplasty alter the results of redo end‐to‐end urethroplasty in patients with traumatic posterior urethral strictures?

Objectives: To evaluate the success rate of redo anastomotic urethroplasty and to compare it with primary anastomotic urethroplasty. Methods: We compared 52 patients with post‐traumatic posterior urethral strictures (group 1, mean age 24.6 years, range 10–62) who had undergone redo urethroplasty with 66 patients (group 2, mean age 22.6, range 6–71) who had undergone primary anastomotic urethroplasty. Mean stricture length was 2.0 cm (1–4.5) and 2.5 cm (1.5–6), respectively. All of the patients in group 1 had a stricture located at the bulboprostatic anastomotic site. In group 2, 43 (65.2%) had a bulbomembranous stricture and 23 (34.8%) had a prostatomembranous stricture. Results: Mean operative time was 140 (100–240) and 90 min (75–200) in group 1 and 2, respectively. Mean blood loss was 180 (80–900) and 125 mL (50–700), respectively. Mean hospital stay was comparable (6.6 days vs 5.5 days) between the two groups. Mean follow up was 54 months (10–144) for group 1 and 62 months (12–122) for group 2. Corporal separation, inferior pubectomy, a transpubic approach and urethral rerouting were required in 22 (42.3%) and 12 (18.2%), 7 (13.5%) and 3 (4.5%), 12 (23%) and 5 (7.6%), 2 (3.8%) and nil patients in group 1 and 2, respectively. An excellent or acceptable outcome was achieved in 42 (80.8%) and 57 (86.4%), 8 (15.4%) and 7 (10.6%) patients, respectively. Two patients in each group failed. Conclusions: Previously failed end‐to‐end urethroplasty does not alter the success rate of redo end‐to‐end urethroplasty.     

Free sensate medial plantar flap for contralateral plantar forefoot reconstruction with flap reinnervation using end‐to‐side neurorrhaphy: A case report and literature review

Reconstruction of weight‐bearing plantar defects remains a challenge due to the unique characteristics of the plantar skin and thus the limited available options. The medial plantar flap, either pedicled or free, represents an ideal option, but its use as sensate flap for forefoot defects has been scarcely reported. We present a case of plantar forefoot reconstruction with a free sensate medial plantar flap, with end‐to‐side coaptation of the cutaneous sensory fascicles of the flap to the medial plantar nerve of the recipient. Last follow‐up, at 2 years post‐op, verified a very good functional and aesthetic outcome, indicating that the suggested approach may prove the treatment of choice in selected cases of plantar forefoot reconstruction. © 2013 Wiley Periodicals, Inc. Microsurgery, 2013.     

Flow‐through fibula flap using soleus branch as distal runoff: A case report

The flow‐through fibula flap utilizing the soleus branch as a distal runoff has not yet been reported. We herein present a patient with left tibial adamantimoma in whom wide resection of the tumor resulted in a segmental tibial defect 22 cm in length. The defect was successfully reconstructed with a flow‐through free fibula osteocutaneous flap using the soleus branch of the peroneal artery as a distal runoff. The short T‐segment of the peroneal artery was interposed to the transected posterior tibial artery. The soleus branch has a constant anatomy and a larger diameter than the distal stump of the peroneal artery. Short interposed flow‐through anastomosis to the major vessels is much easier and more reliable than the conventional methods. We believe that our method represents a versatile option for vascularized fibula bone grafting for extremity reconstruction. © 2012 Wiley Periodicals, Inc. Microsurgery, 2013     

Recanalized umbilico‐caval anastomosis as a temporary portosystemic shunt in pediatric living donor liver transplantation: the crossed fingers method

A temporary portocaval shunt (TPCS) associated with retrohepatic vena cava preservation prevents the edema caused by splanchnic congestion during liver transplantation (LT), especially for non‐cirrhotic cases. We herein report a modified TPCS technique using the recanalized umbilical vein and an end‐to‐side recanalized umbilico‐caval anastomosis for use during pediatric living donor liver transplantation (LDLT). This work evaluated a group of pediatric patients who underwent LDLT between 2001 and 2014 with the conventional TPCS (n=16) vs the recanalized umbilico‐caval shunt (the crossed fingers method, n=10). The crossed fingers method was performed by suturing an end‐to‐side anastomosis of the patent or recanalized umbilical vein to the vena cava using a continuous monofilament suture like “crossing the fingers,” that is, placing the left portal vein across the portal vein trunk next to it. The preoperative, surgical, and postoperative characteristics were similar in both groups except for the significantly shorter portal vein clamping time for the crossed fingers method. This method can allow the portal circulation to be totally decompressed before and after implanting the graft and while maintaining the hemodynamic stability throughout all stages of pediatric LDLT.     

跨区反流轴型皮瓣成活机理的实验研究

目的了解反流轴型皮瓣的成活机理. 方法以Wistar大白鼠左旋髂深血管为蒂,形成8.0 cm×2.5 cm横跨腰背部中线4.0 cm的矩形皮瓣,作为反流轴型皮瓣模型,观察其成活过程中动脉供血和静脉回流的途径、方向和流速、血管管径和管内压力、血流量及血管构筑的改变. 结果皮瓣完全成活率100%,术前中线两侧动脉压差约等于0,术后皮瓣近、远端灌注压差达4.9 kPa;轴心动脉经中线吻合支向对侧供血,经静脉吻合支回流;中线以远区域的血流方向与术前相反.术后48 h内,皮瓣远端血流量仅为术前的1/8～1/5,中线区静脉压高于远端,6例的皮瓣远端静脉淤血;72 h后中线区血管吻合支增多、增粗,静脉压低于远端,远端淤血开始缓解;轴心血管沿吻合支逐渐向中线以远延伸,14 d形成与顺流皮瓣相似的轴心血管,血流量基本恢复到术前水平. 结论反流轴型皮瓣经两侧轴心血管之间的吻合支供血和回流,其动力是吻合支两侧的动、静脉压差.术后72 h内易出现静脉回流障碍,此期皮瓣以代偿性的吻合支增粗、增多及压力下降维持其循环;72 h后,与顺流轴型皮瓣相似的轴心血管逐渐形成, 为皮瓣成活提供了可靠的循环.     

Experimental Study of Micro‐Scale Taylor Vortices Within a Co‐Axial Mixed‐Flow Blood Pump

Taylor vortices in a miniature mixed‐flow rotodynamic blood pump were investigated using micro‐scale particle image velocimetry (μ‐PIV) and a tracer particle visualization technique. The pump featured a cylindrical rotor (14.9 mm diameter) within a cylindrical bore, having a radial clearance of 500 μm and operated at rotational speeds varying from 1000 to 12 000 rpm. Corresponding Taylor numbers were 700–101 800, respectively. The critical Taylor number was observed to be highly dependent on the ratio of axial to circumferential velocity, increasing from 1200 to 18 000 corresponding to Rossby numbers from 0 to 0.175. This demonstrated a dramatic stabilizing effect of the axial flow. The size of Taylor vortices was also found to be inversely related to Rossby number. It is concluded that Taylor vortices can enhance the mixing in the annular gap and decrease the dwell time of blood cells in the high‐shear‐rate region, which has the potential to decrease hemolysis and platelet activation within the blood pump.     

硝苯地平对大鼠颈总动脉端端吻合术后血流速度的影响

目的 研究硝苯地平（ｎｅｆｅｄｉｐｉｎｅ））对小动脉端端吻合后血流速度的影响。为血管吻合后临床应用硝苯地平的时间提供依据。方法 取ＳＤ大鼠４８只,切断左侧颈总动脉后作端端吻合。按术后所给药物的不同随机分成两组。实验组：术后用硝苯地平灌胃（１．０ｍｇ／ｋｇ）;对照组用同等体积生理盐水灌胃。按给药时间又分成术后２４、４８和７２ｈ３个给药时间组。每组均在给药后１、３、５和７ｈ,用彩色多普勒超声仪检测左侧     

Effect of Impeller Geometry on Lift‐Off Characteristics and Rotational Attitude in a Monopivot Centrifugal Blood Pump

The effect of the flow path geometry of the impeller on the lift‐off and tilt of the rotational axis of the impeller against the hydrodynamic force was investigated in a centrifugal blood pump with an impeller supported by a single‐contact pivot bearing. Four types of impeller were compared: the FR model with the flow path having both front and rear cutouts on the tip, the F model with the flow path having only a front cutout, the R model with only a rear cutout, and the N model with a straight flow path. First, the axial thrust and the movement about the pivot point, which was loaded on the surface of the impeller, were calculated using computational fluid dynamics (CFD) analysis. Next, the lift‐off point and the tilt of the rotational axis of the impeller were measured experimentally. The CFD analysis showed that the axial thrust increased gently in the FR and R models as the flow rate increased, whereas it increased drastically in the F and N models. This difference in axial thrust was likely from the higher pressure caused by the smaller circumferential velocity in the gap between the top surface of the impeller and the casing in the FR and R models than in the F and N models, which was caused by the rear cutout. These results corresponded with the experimental results showing that the impellers lifted off in the F and N models as the flow rate increased, whereas it did not in the FR and R models. Conversely, the movement about the pivot point increased in the direction opposite the side with the pump outlet as the flow rate increased. However, the tilt of the rotational axis of the impeller, which oriented away from the pump outlet, was less than 0.8° in any model under any conditions, and was considered to negligibly affect the rotational attitude of the impeller. These results confirm that a rear cutout prevents lift‐off of the impeller caused by a decrease in the axial thrust.     

Modified lambda‐shaped lymphaticovenular anastomosis with supermicrosurgical lymphoplasty technique for a cancer‐related lymphedema patient

Supermicrosurgical lymphaticovenular anastomosis (LVA) has become a useful option for the treatment of compression‐refractory lymphedema with its effectiveness and less invasiveness. It is important to make as many bypasses as possible for better treatment results of LVA operation. We report a secondary lymphedema case successfully treated using a modified lambda‐shaped LVA. A 62‐year‐old female with secondary lower extremity lymphedema (LEL) refractory to conservative treatments underwent LVA operation. A modified lambda‐shaped LVA was performed at the left groin. In modified lambda‐shaped LVA, two lymphatic vessels were transected, and both ends of the proximal and distal sides were converged respectively for an end‐to‐side and end‐to‐end anastomoses to one vein. Using modified lambda‐shaped LVA, four lymph flows of two lymphatic vessels could be bypassed into a vein. Six months after the LVA surgery, her left LEL index decreased from 261 to 247, indicating edematous volume reduction. Modified lambda‐shaped LVA effectively bypasses all lymph flows from two lymphatic vessels, when only one large vein can be found in the surgical field. © 2013 Wiley Periodicals, Inc. Microsurgery 34:308–310, 2014.