Effects of primary suture and fib sealant on hemostasis and liver regeneration in an experimental liver injury

COCu: A Robust Self-Regenerative Hydrogel with Applicability as Both Hydrated Gel Dressing and Dry Suture for Seamless Tissue Fixation and Repair

Self-regenerative hydrogels have recently been developed, and represent a special type of self-healing hydrogels with the ability to restore a dehydrated hydrogel with physical damage. In this study, a self-regenerative hydrogel (COCu) based on two chitosan polymers assembled by slow-released Cu²⁺ is developed. The COCu hydrogel displays an excellent regeneration ability after being dehydrated and fractured. By simple hydration at room temperature, the fragments of the dehydrated gel fuse into one seamless whole, thereby preserving the mechanical properties and functionalities of the original hydrogel. The regeneration process can be conducted repeatedly after different methods of dehydration (natural volatilization, heat drying, lyophilization) and various modes of deconstruction (flakes, powder, lumpy sponge, etc.). Furthermore, the COCu hydrogel provides ultra-stretchability, and it can be stretched into thin (0.01-0.1 mm) filaments, which, when dried (dtCOCu), can be used as suture lines. Moreover, when used as a dry suture, it regenerates into the hydrogel in the presence of the tissue fluid, forming an excellent sealant to immobilize tissues and seamlessly seal wounds. The fast self-regeneration allows for its facile application as both a hydrated gel dressing and dry suture, and offers customized strategies for fixing and repair of different wounds in soft tissues.

Systematic Review of the Management of Retro-Hepatic Inferior Vena Cava Injuries

Background

Retro-hepatic inferior vena cava (RHIVC) injuries resulting from blunt or penetrating abdominal trauma are rare but devastating events that remain a considerable challenge to even the most experienced doctors, which continue to carry a considerable mortality.

Aim

To establish a better understanding of the management of RHIVC injuries and to identify any adjuncts or operative methods that were associated with an increased survival.

Methods

A systematic review of the MEDLINE database was conducted using Medical Search Headings and exploded keywords and phrases. Studies were screened and subjected to inclusion/exclusion criteria. Data were extracted in a methodical manner collecting population demographics, morbidity, mortality and operative intervention, where provided. Operative strategies were compared and discussed.

Results

An initial search identified 483 articles. Following duplicate removal and abstract screening, 85 full-text articles were assessed with 25 meeting the desired criteria and were, therefore, included in the systematic review. Key operative strategies and complications were identified and discussed.

Conclusion

The wide variety of operative interventions in the management of RHIVC liver injuries described attest to the increased efforts to improve outcomes. The overall improvement in mortality can be noted since the earlier descriptions reported mortality approaching 100% compared to the 52% reported in this review. An algorithm has been proposed based on these findings and our experiences for the management of RHIVC injuries.

Hemostatic Efficacy and Safety of the Novel Medical Adhesive, MAR VIVO-107, in a Rabbit Liver Resection Model

Background: Topical hemostatic agents are useful when hepatic hemorrhage is difficult to control. The aim of this study was to evaluate the hemostatic efficacy and safety of a biodegradable polyurethane-based adhesive, MAR VIVO-107 (MAR), in comparison with a clinically used fibrin glue. Methods: Thirty female New Zealand white rabbits were randomly assigned to 3 study groups as follows: MAR (n = 10), fibrin glue (n = 10), and saline groups (n = 10). After standardized partial liver resection was performed, each agent was immediately applied to the wound area. Bleeding time until hemostasis and blood loss were recorded. After 7 days, body weight, hematology parameters, and serum levels of aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase were measured. Simultaneously, the severity of intra-abdominal adhesion was evaluated. Results: The mean bleeding time in the MAR (38 ± 10 s) and fibrin glue groups (65 ± 17 s) was significantly shorter than that in the saline group (186 ± 12 s). Similarly, the mean blood loss in the MAR (9 ± 3 g) and fibrin glue groups (9 ± 3 g) was significantly less than that in the saline group (23 ± 4 g). No significant differences in bleeding time and blood loss were found between the MAR and fibrin glue groups. The postoperative survival rate was 100% in all the groups. Body weight as well as hematological and serum biochemical values on day 7 were within the small and physiological range when compared with the preoperative baseline values, and significant differences were not detected among the MAR, fibrin glue, and saline groups. The severities of adhesion were similar between the 3 groups. Conclusion: Our data demonstrated that MAR was not inferior to fibrin glue in terms of hemostatic efficacy and safety.

Novel synthetic adhesive as an effective alternative to Fibrin based adhesives

AIM

To compare a novel, fully synthetic, polyurethane based glue (MAR-1) to fibrin sealant in a partial liver resection rat model.

METHODS

After 50% resection of the lateral left liver lobe in male Wistar rats (n = 7/group/time point), MAR-1, Fibrin or NaCl was applied. After 14, 21 and 90 postoperative days, sealant degradation, intra-abdominal adhesions were scored, and histological examination of liver tissue was performed.

RESULTS

(Mean ± SEM) (MAR-1 vs Fibrin vs NaCl). Bleeding mass was significantly higher in NaCl (3.36 ± 0.51 g) compared to MAR-1 (1.44 ± 0.40 g) and Fibrin (1.16 ± 0.32 g). At 14 and 90 d, bleeding time was significantly lower in MAR-1 (6.00 ± 0.9 s; 13.57 ± 3.22 s) and Fibrin (3.00 ± 0.44 s; 22.2 ± 9.75 s) compared to NaCl (158.16 ± 11.36 s; 127.5 ± 23.3 s). ALT levels were significantly higher in MAR-1 (27.66 ± 1 U/L) compared to Fibrin (24.16 ± 0.98 U/L) and NaCl (23.85 ± 0.80 U/L). Intrabdominal adhesions were significantly lower in MAR-1 (11.22% ± 5.5%) compared to NaCl (58.57% ± 11.83%). Degradation of the glue was observed and MAR-1 showed almost no traces of glue in the abdominal cavity as compared to the Fibrin (10% ± 5% 14 d; 7% ± 3% 21 d). Survival showed no significant differences between the groups.

CONCLUSION

Compared to Fibrin, MAR-1 showed similar hemostatic properties, no adverse effects, and is biocompatible. Further studies on adhesion strength and biodegradability of synthetic sealants are warranted.

Management of Liver Trauma in Minia University Hospital, Egypt

The aim of this study is to present the outcome of operative and non-operative management of patients with liver injury treated in a single institution depending on imaging. This study was conducted at the Causality Unit of Minia University Hospital, and included 60 patients with hepatic trauma from March 2012 to January 2013. In our study, males represent 80 % while females represent 20 % of the traumatized patients. The peak age for trauma found was 11-30 years. Blunt trauma is the most common cause of liver injury as it was the cause in 48 patients (80 %). Firearm injuries are the most common cause of penetrating trauma (60 %) followed by stab injuries (40 %). More than one half of our patients (34 out of 60) were treated with non-operative management (NOM) with a high success rate. The operative procedures done were suture hepatorrhaphy (20 cases), non-anatomical resection in one case, anatomical resection in one case, and damage control therapy using pads in two cases. In another two cases, nothing was done as subcapsular hematoma had resolved. Minia University Hospital is a big tertiary Hospital in Egypt at which blunt liver trauma is more common than penetrating liver trauma. Surgery is no longer the only option available. It has been reserved for extensive lesions with condition of hemodynamic instability or for the treatment of the complications. NOM is an effective treatment modality in most cases.

Treatment of the liver cross section following hepatectomy

The incidence of complications after hepatectomy has been considerably reduced over the last 20 years. Better knowledge of liver anatomy and liver regeneration, and methods preventing bleeding during surgery have resulted in morbidity rates below 20% and mortality rates less than 5%. The treatment of the liver cross section remains controversial. Experimental studies have reported convincing biological effects of fibrin sealants or compresses when applied on the liver to decrease hemorrhagic or biliary complications. However, clinical studies are very heterogeneous, providing conflicting results compromising recommendations for routine use.