Comparison of pregnancy outcomes and placental characteristics between selective fetal growth restriction with and without thick arterio-arterial anastomosis in monochorionic diamniotic twins

Background Unequal placental territory in monochorionic diamniotic twins is a primary cause of selective fetal growth restriction (sFGR), and vascular anastomoses play important role in determining sFGR prognosis. This study investigated differences in placental characteristics and pregnancy outcomes in cases of sFGR with and without thick arterio-arterial anastomosis (AAA). Methods A total of 253 patients diagnosed with sFGR between April 2013 and April 2020 were retrospectively analyzed. An AAA greater than 2 mm in diameter was defined as a thick AAA. We compared placental characteristics and pregnancy outcomes between cases of sFGR with and without thick AAA. Results Prevalence of AAA, thick arterio-venous anastomosis (AVA), veno-venous anastomosis (VVA), and thick VVA were significantly higher in the thick AAA group relative to the non-thick AAA group (100.0 vs. 78.5%, P < 0.001; 44.3 vs. 15.4%, P < 0.001; 27.1 vs. 10.8%, P = 0.017, and 24.3 vs. 6.2%, P = 0.004, respectively). The total numbers of AVA and total anastomoses were significantly higher in thick AAA group relative to the non-thick AAA group (5 [1, 14] vs. 3 [1, 15, P = 0.016; and 6 [1, 15] vs. 5 [1, 16], P = 0.022, respectively). The total diameter of AAA, AVA, VVA, and all anastomoses in the thick AAA group was larger than in the non-thick AAA group (3.4 [2.0,7.1] vs. 1.4 [0.0, 3.3], P < 0.001; 6.3 [0.3, 12.0] vs. 2.5 [0.3, 17.8], P < 0.001; 4.2±1.8 vs. 1.9±1.2, P =0.004; and 10.7 [3.2,22.4] vs. 4.4 [0.5, 19.3], P < 0.001, respectively). Growth-restricted fetuses in the thick AAA group exhibited significantly increased birthweight relative to those in thenon-thick AAA group (1570 (530, 2460)g vs. 1230 (610, 2480)g, p = 0.002). Conclusions In the placentas associated with sFGR, thick AAA can co-occur with thick AVA and VVA, and placental angiogenesis may differ significantly based upon whether or not thick AAA is present. The birth weights of growth-restricted fetuses in cases of sFGR with thick AAA are larger than in cases without thick AAA.

Bedside Neck Exploration for Venous Flow Coupler Signal Loss in Postoperative Free Tissue Transfer Monitoring

Objective To describe the role and efficacy of bedside neck exploration following free tissue transfer. Study Design Retrospective case series. Setting Single tertiary care institution. Methods A retrospective chart review was conducted of 353 patients who underwent free tissue transfer between January 2017 and April 2021. Bedside exploration was performed under mild sedation in patients who had loss of venous Doppler signal with equivocal clinical signs of venous insufficiency. Results A total of 11 patients underwent bedside assessment of the microvascular pedicle. In 6 cases, a return to the operating room was avoided. Five of these patients had coupler malfunction, and in 1 patient a venous kink was discovered and remedied at the bedside. Five patients required return to the operating room. Venous thrombosis requiring thrombectomy and revision of the venous anastomosis was discovered in 3 patients. One patient had a developing hematoma necessitating evacuation in the operating room, and 1 returned to the operating room due to sternocleidomastoid muscular compression of the venous pedicle. There were no flap failures within the study group. In all cases, broad-spectrum intravenous antibiotic coverage was prophylactically used, and no instances of wound infection were observed. Avoidance of returning to the operating room prevented an estimated $9222 of hospital charges per event. Conclusion Bedside neck exploration can be incorporated as a safe and cost-effective intermediary for definitive determination of need for return to the operating room.

Long-term outcomes of thigh arteriovenous graft stenting

Background: Stents have been increasingly used for treating venous anastomosis stenosis seen in arteriovenous grafts (AVGs). A major reason for this trend is that stents can potentially confer a better patency rate compared to angioplasty. However, limited data are available about the outcomes of stents that are used to treat thigh AVG dysfunction. This study sought to assess the primary and secondary patency rates of stents used to treat thigh AVGs dysfunction at one year. Methods: This is a retrospective study of dialysis patients who received therapy via thigh grafts (N=50) and underwent stent placement between January 2005 and June 2017 at our center. Data on demographics and baseline characteristics of the study population were collected. The primary and secondary patency rates were defined as the time between stent deployment and the first intervention and second intervention, respectively. Patency and re-intervention rates were estimated using Kaplan-Meier survival analysis. Results: This study included 50 patients with thigh AVGs; mean age was 50.5± 15.5 years; 52% were female; 80% were black; and 90% had hypertension. The main indication for stenting was thrombosis due to venous anastomosis stenosis (74%). The number (mean ± SD) of stents deployed was 1.24 ± 0.8. The primary patency rate at three months and one year was 58.7% and 30.7%. In comparison, the secondary patency rate at three months and one year was 68.2% and 40.7% (p=0.04) Conclusions: Thigh AVG stenting can be successfully used to improve the overall patency rates of failing AVGs.

Hemodynamic Analysis on the Anastomosis Angle in Arteriovenous Graft Using Multiphase Blood Model

Numerical analysis was performed for the effect of the venous anastomosis angle in a forearm arteriovenous graft for hemodialysis using a multiphase blood model. The geometry of the blood vessel was generated based on the patient-computed tomography data. The anastomosis angles were set at 15°, 30°, and 45°. The hematocrit was set at 34%, 45%, and 58%. The larger anastomosis angle, high wall shear stress area >11 Pa, increases to the side of the vein wall away from the anastomosis site. Further, the relatively low wall shear stress area, <3 Pa, occurs near the anastomosis site in larger anastomosis angles. Therefore, the effect of high wall shear stress has advantages in the vicinity of the anastomosis, as the anastomosis angle is larger, but disadvantages as the distance from the anastomosis increases. Moreover, patients with low hematocrit are advantageous for WSS area.

722 SAFE (SUPERCHARGED CERVICAL ANASTOMOSIS FOR ESOPHAGECTOMY AND GASTRIC PULL-UP) PROCEDURE: LONG TERM RESULTS FROM 61 PATIENTS

Esophagectomy still represents a challenge surgical procedure. Anastomotic leakage is the most feared complication and is likely related to diminished anastomotic perfusion. ‘Supercharged’ microvascular anastomosis has been performed in select patients to supplement the blood supply to the graft and anastomosis, after esophagectomy. This study aimed to evaluate results after performing the supercharged cervical anastomosis for esophagectomy procedure. Methods This prospective cohort study evaluated patients who underwent esophagectomy with gastric reconstruction and cervical anastomosis for locally advanced esophageal carcinoma. Patients were selected in which cervical anastomosis using the supercharged cervical anastomosis for esophagectomy procedure was performed. The anastomotic perfusion areas were evaluated using indocyanine and SPY before and after supercharged cervical anastomosis for esophagectomy. Post esophagectomy complications were also recorded. Results The study enrolled 61 patients, which included 47 (77.0%) men, with a mean age of 67.3 years. Median additional surgical time was 112 min (IQ 90–180), Leakage occurred in 1.6% of the patients (microanastomosis thrombosis), whereas the corresponding anastomotic stricture rates were 3.2% (mean follow-up was 25 mounths). Perfusion analyses showed a 28% improvement in the anastomotic area after venous anastomosis and a 37% improvement after arterial and venous anastomosis. Conclusion The supercharged cervical anastomosis for esophagectomy procedure may be related to low occurrence of anastomotic leakage and improve perfusion in the anastomotic area via vein and arterial microanastomoses.