Factors affecting polyglycolic acid sheet engraftment success for covering mucosal defects from head and neck surgery.

BACKGROUND: Polyglycolic acid (PGA) sheets have been used with fibrin glue to cover extensive mucosal defects in oral and pharyngeal surgery; however, the sheets can fall off before wound healing is completed. Hence, prolonged fasting is often recommended in such patients. However, there are few studies on the factors that shape PGA sheet engraftment. We studied sheet engraftment rates considering these factors. METHODS: All consecutive cases of oral surgery in 2013-21 in which the defect was covered with fibrin glue and Neoveil® or Neoveil Nano® PGA sheets were identified. The loss of all sheets was defined as an engraftment failure. Multiple logistic regression analysis was conducted to identify whether the PGA-sheet type, application site, defect size and postoperative fasting duration predicted engraftment. RESULTS: Overall, 137 patients were identified (mean age, 73 years; 57% male). The surgeries were conducted with Neoveil® in 66% of the patients; the most common site was the buccal mucosa (25%), and the mean defect size and fasting duration were 709 mm2 and 4 days, respectively. The engraftment rate was 76%. Neoveil Nano® PGA sheets were associated with a 2.8-fold better engraftment rate than Neoveil® (univariate: 87 vs. 70%, P = 0.032; multivariate: 95% confidence intervals = 1.067-7.410, P = 0.036). Other variables, including fasting duration, were not predictive of engraftment. CONCLUSIONS: This is the largest case series of patients with head and neck cancer who underwent fibrin glue-PGA sheet defect coverage. The fasting duration did not influence engraftment. Therefore, early oral intake is not contraindicated in such patients.

Repeated steroid injection and polyglycolic acid shielding for prevention of refractory esophageal stricture.

BACKGROUND: Postoperative stricture and refractory stricture are severe adverse events which occur after expansive esophageal endoscopic submucosal dissection (ESD). The aim of this study was to assess the efficacy of steroid injection, polyglycolic acid (PGA) shielding, and of additional steroid injection thereafter for the prevention of refractory esophageal stricture. METHODS: This is a retrospective cohort study of 816 consecutive cases of esophageal ESD performed between 2002 and 2021 at the University of Tokyo Hospital. After 2013, all patients with a diagnosis of superficial esophageal carcinoma covering over 1/2 the esophageal circumference underwent preventive treatment immediately after ESD with either "PGA shielding", "steroid injection", or "steroid injection + PGA shielding". Additional steroid injection was performed for high-risk patients after 2019. RESULTS: The risk of refractory stricture was especially high in the cervical esophagus (OR 24.77, p = 0.002) and after total circumferential resection (OR 894.04, p < 0.001). "Steroid injection + PGA shielding" was the only method significantly effective in preventing stricture occurrence (OR 0.36; 95% CI 0.15-0.83, p = 0.012). This method also decreased the risk of refractory stricture (OR 0.38; 95% CI 0.10-1.28, p = 0.096), but additional steroid injection was the only significantly effective method for prevention of refractory stricture (OR 0.42; 95% CI 0.14-0.98, p = 0.029). CONCLUSION: Combining steroid injection and PGA shielding is effective for preventing post-ESD stricture and refractory stricture. Additional steroid injection is a viable option for patients at high-risk for refractory stricture.

Evaluating the Efficacy of Polyglycolic Acid-Loading Tetrandrine Nanoparticles in the Treatment of Dry Eye.

INTRODUCTION: Dry eye disease (DED) is a multifactor-induced disease accompanied by increased osmolarity of the tear film and inflammation of the ocular surface. Traditional anti-inflammation agent corticosteroids applied in DED treatment could result in high intraocular pressure, especially in long-term treatment. Therefore, we explored a nano drug that aimed to block the formation pathway of DED which had anti-inflammatory, sustained release, and good biocompatibility characteristics in this study. METHODS: We prepared a novel nanomedicine (Tet-ATS@PLGA) by the thin film dispersion-hydration ultrasonic method and detected its nanostructure, particle size, and zeta potential. Flow cytometry was used to detect the cell survival rate of each group after 24 h of drug treatment on inflammed Statens Seruminstitut Rabbit Corneal (SIRC) cells. Observed and recorded corneal epithelial staining, tear film rupture time, and Schirmer test to detect tear secretion on the ocular surface of rabbits. The corneal epithelial thickness, morphology, and number of bulbar conjunctival goblet cells were recorded by H&E staining. Finally, we detected the expression of VEGF, IL-1ß, PGE2, and TNF-α by cellular immunofluorescence staining and enzyme-linked immunosorbent assay (ELISA). RESULTS: The encapsulation efficiency and drug loading of Tet-ATS@PLGA were 79.85% and 32.47%, respectively. At eye surface temperature, Tet can easily release from Tet-ATS@PLGA while that it was difficult to release at storage temperature and room temperature. After 2 weeks medication, Tet-ATS@PLGA can effectively improve the tear film rupture time and tear secretion time in a DED model (p <0.05). Compared with the normal group (62.34 ± 4.86 mm), the thickness of corneal epithelium in ATS (29.47 ± 3.21 mm), Tet-ATS (46.23 ± 2.87 mm), and Tet-ATS@PLGA (55.76 ± 3.95 mm) gradually increased. Furthermore, the flow cytometry indicated that Tet-ATS@PLGA can effectively promote the apoptosis of inflammatory SIRC cells, and the cellular immunofluorescence and ELISA experiments showed that the expression intensity of inflammatory factors such as VEGF, IL-1ß, PGE2, and TNF-α decreased in this process. Interestingly, Tet also had the effect of reducing intraocular pressure. CONCLUSION: Tet-ATS@PLGA can effectively promote the apoptosis of inflammatory corneal epithelial cells, thus inhibiting the expression of inflammatory factors to block the formation of DED and improve the secretion of tear on the ocular surface.

Efficacy of the polyglycolic acid sheet for preventing anastomotic leakage in double-stapling technique anastomosis for left-sided colon or rectal cancer surgery: a propensity score-matched study.

BACKGROUND: To prevent anastomotic leakage in patients with left-sided colorectal cancer who underwent double-stapling technique (DST) anastomosis, we investigated a new method: DST anastomosis with a polyglycolic acid (PGA) sheet. This procedure has been shown to have the potential to decrease the rate of anastomotic leakage. However, due to the small number of cases enrolled in our previous study, it was not possible to compare the outcomes of the new and conventional procedures. The aim of this study was to evaluate the effect of the PGA sheet on preventing anastomotic leakage in patients with left-sided colorectal cancer who underwent DST anastomosis by retrospectively comparing the anastomotic leakage rate between the PGA sheet and conventional groups. METHODS: A total of 356 patients with left-sided colorectal cancer who underwent DST anastomosis during surgery at Osaka City University Hospital between January 2016 and April 2022 were enrolled in this study. Propensity score matching was performed to reduce the confounding effects secondary to imbalances in the use of PGA sheets. RESULTS: The PGA sheet was used in 43 cases (PGA sheet group) and it was not used in 313 cases (conventional group). After propensity score matching, the incidence of anastomotic leakage in the PGA sheet group was significantly lower than that in the conventional group. CONCLUSION: DST anastomosis with PGA sheet, which is easy to perform, contributes to the reduction of anastomotic leakage rate by increasing the strength of the anastomotic site.

Efficacy of polyglycolic acid sheeting with fibrin glue for perforations related to gastrointestinal endoscopic procedures: a multicenter retrospective cohort study.

OBJECTIVES: Gastrointestinal (GI) perforations are one of the major adverse events of endoscopic procedures. Polyglycolic acid (PGA) sheets with fibrin glue have been reported to close GI perforations. However, its clinical outcome has not yet been fully investigated; thus, we conducted a multicenter retrospective observational study to assess the efficacy of PGA sheeting for GI perforation. METHODS: The medical records of patients who underwent PGA sheeting for endoscopic GI perforations between April 2013 and March 2018 in 18 Japanese institutions were retrospectively analyzed. PGA sheeting was applied when the clip closure was challenging or failed to use. Perforations were filled with one or several pieces of PGA sheets followed by fibrin glue application through an endoscopic catheter. Nasal or percutaneous drainage and endoscopic clipping were applied as appropriate. Clinical outcomes after PGA sheeting for intraoperative or delayed perforations were separately evaluated. RESULTS: There were 66 intraoperative and 24 delayed perforation cases. In intraoperative cases, successful closure was attained in 60 cases (91%). The median period from the first sheeting to diet resumption was 6 days (interquartile range [IQR], 4-8.8 days). Large perforation size (≥ 10 mm) and duodenal location showed marginal significant relationship to higher closure failure of intraoperative perforations. In delayed perforation cases, all cases had successful closure. The median period from the first sheeting to diet resumption was 10 days (IQR, 6-37.8 days). No adverse events related to PGA sheeting occurred. CONCLUSION: Endoscopic PGA sheeting could be a therapeutic option for GI perforations related to GI endoscopic procedures.

Wrapping the pancreas with a polyglycolic acid sheet before stapling reduces the risk of fluid collection on the pancreatic stump after distal pancreatectomy.

BACKGROUND: Postoperative pancreatic fistula (POPF) and postoperative fluid collection (POFC) are common complications after distal pancreatectomy (DP). The previous method of reducing the risk of POPF was the application of a polyglycolic acid (PGA) sheet to the pancreatic stump after cutting the pancreas with a stapler (After-stapling); the new method involves wrapping the pancreatic resection line with a PGA sheet before stapling (Before-stapling). The study aimed to compare the incidence of POPF and POFC between two methods. METHODS: Data of patients who underwent open or laparoscopic DPs by a single surgeon from October 2010 to February 2020 in a tertiary referral hospital were retrospectively analyzed. POPF was defined according to the updated International Study Group of Pancreatic Fistula criteria. POFC was measured by postoperative computed tomography (CT). RESULTS: Altogether, 182 patients were enrolled (After-stapling group, n = 138; Before-stapling group, n = 44). Clinicopathologic and intraoperative findings between the two groups were similar. Clinically relevant POPF rates were similar between both groups (4.3% vs. 4.5%, p = 0.989). POFC was significantly lesser in the Before-stapling group on postoperative day 7 (p < 0.001). CONCLUSIONS: Wrapping the pancreas with PGA sheet before stapling was a simple and effective way to reduce POFC.

Thoracoscopic Repair of Adult-Onset Congenital Tracheoesophageal Fistula Using a Polyglycolic Acid Sheet-Buttressed Stapler.

Congenital tracheoesophageal fistula (TEF) without esophageal atresia is usually diagnosed and treated in the neonatal period. It is uncommon to occur in adulthood. Conventional treatment of adult-onset TEF involves repair by either cervicotomy or thoracotomy. We reported the case of a 31-year-old male patient with clinical and radiographic evidence of congenital H-type TEF. Although this fistula was located at the level of the second thoracic vertebra, the repair of the anomaly was performed successfully using a thoracoscopic approach with the novel use of a polyglycolic acid sheet reinforcement.

Treatment of air leakage using the VIO soft coagulation system: a mouse pulmonary air leak model.

PURPOSE: We aimed to compare the efficacy of the VIO soft coagulation system (VSCS) for the treatment of air leaks by sealing with fibrin glue, and also assess the histological alterations that occur after soft coagulation. METHODS: A mouse pulmonary air leak model was designed. The pulmonary fistula was subsequently coagulated with the VSCS or sealed with fibrin glue with polyglycolic acid (PGA) sheets. The burst pressure at air leak recurrence was measured in each group, and the results were compared. We also evaluated the histological alterations in the mouse pulmonary air leak model after soft coagulation with the VSCS. RESULTS: The burst pressure in the soft coagulation group (80 W/Effect 5) (median 42.8; range 35.4-53.8 cmH2O) was similar to that in the fibrin glue group (median 41.5; range 34.6-43.9 cmH2O) (p = 0.21). Histological examinations revealed that the visceral pleura remained torn, the structure of the pulmonary alveolus was maintained, and the coagulated fistula was covered with a fibrin membrane in the soft coagulation group. CONCLUSIONS: The pressure resistance following soft coagulation was equivalent to that after sealing using fibrin glue with PGA sheets. The air leaks were likely controlled by covering the fistula with a fibrin membrane after soft coagulation with the VSCS.

Efficacy of endoscopic filling with polyglycolic acid sheets and fibrin glue for anastomotic leak after esophageal cancer surgery: identification of an optimal technique.

BACKGROUND: Anastomotic leak is a potentially life-threatening complication following esophageal cancer surgery. In this study, we aimed to clarify the efficacy of endoscopic filling with polyglycolic acid (PGA) sheets and fibrin glue for anastomotic leak after esophageal cancer surgery. METHODS: Consecutive patients who underwent endoscopic filling with PGA sheets and fibrin glue for anastomotic leak after esophageal cancer surgery between August 2014 and January 2020 were included in the study, with its efficacy retrospectively reviewed. We performed endoscopic filling using two methods: (1) filling the fistula with PGA sheets, followed by the application of a fibrinogen and thrombin solution (conventional method) and (2) filling the fistula with PGA sheets pre-soaked in a fibrinogen solution, followed by the application of a thrombin solution (pre-soak method). RESULTS: A total of 14 patients underwent endoscopic filling procedures within the study period. The endoscopic filling procedures were successfully performed in all cases and no adverse events associated with the procedures were observed. Fistula closure was obtained in 10 (71%) cases. In the 10 successful cases, the median number of procedures was 1 (range 1-3) and the median time from the first procedure to oral intake was 7.5 days (range 4-36 days). The success rate of the pre-soak method was significantly higher than that of the conventional method (90% vs. 25%, P = 0.041). CONCLUSIONS: Endoscopic filling with PGA sheets and fibrin glue is a safe and effective treatment for the closure of an anastomotic leak. The pre-soak method can achieve successful endoscopic filling.

Endoscopic plombage with polyglycolic acid sheets and fibrin glue for gastrointestinal fistulas.

BACKGROUND AND STUDY AIMS: Gastrointestinal (GI) fistulas arise as adverse events of GI surgery and endoscopic treatment as well as secondary to underlying diseases, such as ulceration and pancreatitis. Until a decade ago, they were mainly treated surgically or conservatively. Bioabsorbable polyglycolic acid (PGA) sheets and fibrin glue, which are commonly used in surgical procedures, have also recently been used in endoscopic procedures for the closure of GI defects. However, there have only been few case reports about successful experiences with this approach. There have not been any case-series studies investigating the strengths and weaknesses of such PGA sheet-based treatment. In this study, we evaluated the clinical effectiveness of using PGA sheets to close GI fistulas. PATIENTS AND METHODS: Cases in which patients underwent endoscopic filling with PGA sheets and fibrin glue for GI fistulas at Kobe University Hospital between January 2013 and April 2018 were retrospectively reviewed. RESULTS: A total of 10 cases were enrolled. They included fistulas due to leakage after GI surgery, aortoesophageal/bronchoesophageal fistulas caused by chemoradiotherapy, or severe acute pancreatitis. The fistulas were successfully closed in 7 cases (70%). The unsuccessful cases involved a fistula due to leakage after surgical esophagectomy and bronchoesophageal fistulas due to chemoradiotherapy or severe acute pancreatitis. Unsuccessful treatment was related to fistula epithelization. CONCLUSION: Endoscopic plombage with PGA sheets and fibrin glue could be a promising therapeutic option for GI fistulas.

Bioglass/PLGA associated to photobiomodulation: effects on the healing process in an experimental model of calvarial bone defect.

Bioactive glasses (BG) are known for their ability to bond to bone tissue. However, in critical situations, even the osteogenic properties of BG may be not enough to induce bone consolidation. Thus, the enrichment of BG with polymers such as Poly (D, L-lactic-co-glycolic) acid (PLGA) and associated to photobiomodulation (PBM) may be a promising strategy to promote bone tissue healing. The aim of the present study was to investigate the in vivo performance of PLGA supplemented BG, associated to PBM therapy, using an experimental model of cranial bone defect in rats. Rats were distributed in 4 different groups (Bioglass, Bioglass/PBM, Bioglas/PLGA and BG/PLGA/PBM). After the surgical procedure to induce cranial bone defects, the pre-set samples were implanted and PBM treatment (low-level laser therapy) started (808 nm, 100 mW, 30 J/cm2). After 2 and 6 weeks, animals were euthanized, and the samples were retrieved for the histopathological, histomorphometric, picrosirius red staining and immunohistochemistry analysis. At 2 weeks post-surgery, it was observed granulation tissue and areas of newly formed bone in all experimental groups. At 6 weeks post-surgery, BG/PLGA (with or without PBM) more mature tissue around the biomaterial particles. Furthermore, there was a higher deposition of collagen for BG/PLGA in comparison with BG/PLGA/PBM, at second time-point. Histomorphometric analysis demonstrated higher values of BM.V/TV for BG compared to BG/PLGA (2 weeks post-surgery) and N.Ob/T.Ar for BG/PLGA compared to BG and BG/PBM (6 weeks post-surgery). This current study concluded that the use of BG/PLGA composites, associated or not to PBM, is a promising strategy for bone tissue engineering.

A novel dual-covering method in video-assisted thoracic surgery for pediatric primary spontaneous pneumothorax.

BACKGROUND: Primary spontaneous pneumothorax (PSP) generally occurs in young adults, whereas pediatric PSP is uncommon. It is difficult to source reliable data on pediatric PSP, the management of which is based on guidelines for adult PSP; however, the rate of recurrence after video-assisted thoracoscopic surgery (VATS) for pediatric PSP is reported to be higher. METHODS: We reviewed retrospectively a collective total of 66 surgical cases of a first pneumothorax episode in 46 children under 16 years of age, who were treated at our hospital between February, 2005 and November, 2017. RESULTS: The surgical cases were divided into two groups, depending on how the treated lesions were covered. In the dual-covering (DC) group, the PSP was covered by oxidized regenerated cellulose and polyglycolic acid (8 patients; 13 cases) and in the single-covering (SC) group, the PSP was covered by oxidized regenerated cellulose (38 patients; 53 cases). There was no incidence of recurrence after surgery in the DC group, but 17 cases (32.1%) of recurrence after surgery in the SC group. This difference was significant. CONCLUSION: The DC method prevented the recurrence of PSP more effectively than the SC method after VATS in pediatric patients. Long-term follow-up after VATS for pediatric PSP is also important because of the risk of delayed recurrence.

Clinical outcome and ultrasonographic evaluation of treatment using polyglycolic acid-collagen tube for chronic neuropathic pain after peripheral nerve injury.

BACKGROUND: A novel polyglycolic acid (PGA)-collagen tube has been available in Japan since March 2013, and the development of high-resolution ultrasonography has recently allowed detailed evaluation of nerves. The purpose of this study was to report the clinical outcomes and evaluations of in-vivo changes under high-resolution ultrasonography for treatment using PGA-collagen tube for painful chronic nerve injury. METHODS: Four patients underwent surgical management of peripheral nerve neuroma, with nerve defects after neuroma resection reconstructed using PGA-collagen tube. Mean duration of follow-up was 30 months. Patients were surveyed to determine visual analog scale scores for pain before surgery and at final follow-up. At final follow-up, sensory function was evaluated using the Semmes-Weinstein test, static 2-point discrimination (2PD), and moving 2PD. Furthermore, we performed ultrasonography for all patients every 1 month after surgery. RESULTS: In all cases, resting pain, radicular pain, and dysesthesia were improved immediately after the operation and remained improved until the last follow-up. At the time of final follow-up, the Semmes-Weinstein test was red in 2 cases and blue in 2 cases. Mean static 2PD was 15.5 ± 5.3 mm and mean moving 2PD was 11.5 ± 5.3 mm. Ultrasonography revealed that the PGA outer wall had disappeared by 3 months postoperatively, and a hypoechoic linear shadow bridged the proximal and distal stumps. Swelling of the junction between nerve and nerve conduits was revealed at 4 months after surgery and remained until last follow-up. CONCLUSIONS: All patients were very satisfied with pain relief, but recovery of sensory function was insufficient. Ultrasonographic evaluation after using PGA-collagen tube for painful chronic peripheral nerve injury was useful for observing in-vivo changes. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Efficacy of polyglycolic acid sheets and fibrin glue for prevention of bleeding after gastric endoscopic submucosal dissection in patients under continued antithrombotic agents.

BACKGROUND: A novel method for the prevention of bleeding after gastric endoscopic submucosal dissection (ESD) is necessary, as the numbers of patients taking antithrombotic agents have increased. This study aimed to assess the efficacy and safety of the covering method using polyglycolic acid (PGA) sheets and fibrin glue for ESD-induced ulcer in preventing post-ESD bleeding in patients under continued antithrombotic agents. METHODS: One hundred five consecutive gastric tumors among 84 patients who were treated by ESD under continued antithrombotic agents between April 2014 and September 2015 were enrolled in this study. The patients were classified into two groups, the covering group (52 lesions among 38 patients; those with ESD in whom PGA sheets and fibrin glue were used as the covering method) and the control group (53 lesions among 46 patients; ESD only), and their post-ESD bleeding rates were compared. RESULTS: No significant differences were seen in the number and type of antithrombotic agents, lesion location, median procedure time, and median resected specimen size between the groups. ESD was completed in all cases, with no cases of uncontrollable bleeding during the procedure. Post-ESD bleeding occurred in 5.8% (3/52) and 20.8% (11/53) in the covering and control groups, respectively. The post-ESD bleeding rate significantly differed between the groups (P = 0.04; odds ratio, 0.23; 95% confidential interval, 0.06-0.89). No adverse events were associated with the use of PGA sheets and fibrin glue. CONCLUSIONS: The covering method using PGA sheets and fibrin glue has the potential to reduce post-ESD bleeding in patients receiving continued antithrombotic agents.

Polyglycolic Acid Felt for Prevention of Frey Syndrome After Parotidectomy.

BACKGROUND: Frey syndrome is one of the important complications of parotid surgery. Placing a barrier between the parotid gland and the skin flap is considered to be effective for preventing this syndrome by blocking misdirected regeneration of nerve fibers. Neoveil is nonwoven polyglycolic acid (PGA) felt that is used as absorbable reinforcing material. The present study evaluated the effectiveness of this PGA felt as a barrier for preventing Frey syndrome. METHODS: A total of 19 patients who underwent superficial parotidectomy from 2012 to 2017 were retrospectively reviewed. Application of PGA felt (n = 9) or sternocleidomastoid flap (SCMF) transfer (n = 10) was performed to prevent Frey syndrome. The total operating time, intraoperative blood loss, operating time after parotidectomy, and postoperative drainage volume were compared between the 2 groups. RESULTS: The operating time after parotidectomy was significantly shorter in the PGA felt group than in the SCMF group (43.7 ± 10.7 vs 57.8 ± 15.7 minutes). The total operative time was shorter and the drainage volume was smaller in the PGA felt group than those in the SCMF group without statistical significance (210.1 ± 43.4 vs 234.3 ± 52.7 minutes and 80.6 ± 36.8 vs 118.8 ± 83.9 mL). Neither Frey syndrome nor other major complications occurred in either group. CONCLUSIONS: Use of PGA felt successfully prevented Frey syndrome, while being technically simpler and more rapid compared with SCMF transfer.