The Ischemic Tolerance up to Four Hours of Free Jejunum Flap: A Retrospective Cohort Study.

BACKGROUND: While free jejunum transfer (FJT) following total pharyngo-laryngo-esophagectomy (TPLE) is a reliable reconstruction technique, the jejunum flap is viewed as more susceptible to ischemia than a standard free flap. Animal studies have indicated that the jejunum can tolerate ischemia for as little as 2 to 3 hours. Clinical studies also reported increased complications after the FJT with more than 3 hours of ischemia. Traditionally, our institution has carried out FJT with an initial intestinal anastomosis, followed by a vascular anastomosis, which often results in extended jejunal ischemia time. In this study, we retrospectively examined the actual tolerance of the jejunum to ischemia, considering perioperative complications and postoperative dysphagia. METHODS: We retrospectively studied 402 consecutive cases involving TPLE + FJT. Patients were divided into five groups based on jejunum ischemia time (∼119 minutes, 120∼149 minutes, 150∼179 minutes, 180∼209 minutes, 210 minutes∼), with each variable and result item compared between the groups. Univariate and multivariate analyses were conducted to identify independent factors influencing the four results: three perioperative complications (pedicle thrombosis, anastomotic leak, surgical site infection) and dysphagia at 6 months postoperatively. RESULTS: The mean jejunal ischemia time was 164.6 ± 28.4 (90-259) minutes. When comparing groups divided by jejunal ischemia time, we found no significant differences in overall outcomes or complications. Our multivariate analyses indicated that jejunal ischemia time did not impact the three perioperative complications and postoperative dysphagia. CONCLUSION: In TPLE + FJT, a jejunal ischemia time of up to 4 hours had no effect on perioperative complications or postoperative dysphagia. The TPLE + FJT technique, involving a jejunal anastomosis first followed by vascular anastomosis, benefits from an easier jejunal anastomosis but suffers from a longer jejunal ischemia time. However, we found that ischemia time does not pose significant problems, although we have not evaluated the effects of jejunal ischemia extending beyond 4 hours.

Effect of Dietary 4-Phenylbuthyric Acid Supplementation on Acute Heat-Stress-Induced Hyperthermia in Broiler Chickens.

Hot, humid weather causes heat stress (HS) in broiler chickens, which can lead to high mortality. A recent study found that HS causes endoplasmic reticulum (ER) stress. However, the possible involvement of ER stress in HS-induced physiological alterations in broiler chickens is unclear. This study aimed to evaluate the effect of the dietary supplementation of 4-phenylbutyric acid (4-PBA), an alleviator of ER stress, in acute HS-exposed young broiler chickens. Twenty-eight 14-day-old male broiler chickens (ROSS 308) were divided into two groups and fed either a control diet or a diet containing 4-PBA (5.25 g per kg of diet feed) for 10 days. At 24 days old, each group of chickens was kept in thermoneutral (24 ± 0.5 °C) or acute HS (36 ± 0.5 °C) conditions for 2 h. The results showed that thermoneutral birds supplemented with 4-PBA exhibited no negative effects in terms of broiler body weight gain and tissue weight compared to non-supplemental birds. HS increased body temperature in both the control and 4-PBA groups, but the elevation was significantly lower in the 4-PBA group than in the control group. The plasma non-esterified fatty acid concentration was significantly increased by HS treatment in non-supplemental groups, while the increase was partially attenuated in the 4-PBA group. Moreover, 4-PBA prevented HS-induced gene elevation of the ER stress markers GRP78 and GRP94 in the skeletal muscle. These findings suggest that the 4-PBA effect may be specific to the skeletal muscle in HS-exposed birds and that 4-PBA supplementation attenuated HS-induced muscle ER stress, which could be associated with a supplementation of the body temperature elevation and lipolysis.

The concept of "whole perforator system" in the lateral thoracic region for latissimus dorsi muscle-preserving large flaps: An anatomical study and case series.

BACKGROUND: Previous studies have reported on the abundant cutaneous perforating blood vessels around the latissimus dorsi (LD) lateral border, such as a thoracodorsal artery perforator (TDAP) of septocutaneous type (TDAP-sc) and muscle-perforating type (TDAP-mp), or the lateral thoracic artery perforator (LTAP). These perforators have been clinically utilized for flap elevation; however, there have been few studies that accurately examined all the cutaneous perforators (TDAP-sc, TDAP-mp, LTAP) around the LD lateral border. Here, we propose a new "whole perforator system" (WPS) concept in the lateral thoracic region and a methodology that enables elevating large flaps with reliable perfusion in a muscle-preserving manner. METHODS: We first performed an anatomical study that verified the number and perforating points of all perforators around the LD lateral border using the results of dynamic contrast-enhanced magnetic resonance imaging of patients with breast cancer. Following the anatomical evaluation, we performed large muscle-preserving flap transfer that contained all of the perforators around the LD lateral border in an actual clinical setting. RESULTS: A total of 175 latissimus dorsi from 98 patients were included. The mean number of perforators (TDAP-sc + TDAP-mp + LTAP) per side was 4.51±1.44 (2-9); TDAP-sc was present in 57.1% (100/175) of cases, and TDAP-mp in 76.6% (134/175); the TDAP total prevalence rate (TDAP-sc + TDAP-mp) was 96.0% (168/175). The LTAP existence rate was 94.3% (165/175). Distance from the axillary artery to the TDAP-sc was 148.7±56.3 mm, which was significantly proximal to the TDAP-mp (183.8±54.2 mm) and LTAP (172.2±81.3 mm). CONCLUSION: The lateral thoracic region has an abundant cutaneous perforator system derived from the descending branch of the thoracodorsal and lateral thoracic arteries. Clinical application of the lateral thoracic WPS flap is promising, with a large survival area even with muscle-preserving procedures and requiring a relatively simple procedure.