Carbon Monoxide-Related Vision Loss in an Acute Burn Patient.

Carbon monoxide poisoning can occur as part of smoke exposure in the burn population. Here we report the case of a 32-year-old, previously healthy male, with carbon monoxide-related blindness after smoke exposure in an apartment fire. Cerebral hypoperfusion was diagnosed using magnetic resonance imaging of the brain, and the patient was diagnosed with cortical visual impairment. He was treated with hyperbaric oxygen therapy following which he had partial recovery of his vision. There is a paucity of information regarding this phenomenon and its treatment.

Care of the Critically Injured Burn Patient.

Care of the critically injured burn patient presents unique challenges to the intensivist. Certified burn centers are rare and geographically sparse, necessitating that much of the initial management of patients with severe burn injuries must happen in the pre-burn center setting. Severe burn injuries often lead to a wide range of complications that extend beyond the loss of skin integrity and require specialized care. As such, medical intensivists are often called on to stabilize these critically injured patients. This focused review outlines the clinical care of these medically complex patients, including airway management, postburn complications, volume resuscitation, nutrition, and end-of-life care.

Toxic Clostridioides (formerly Clostridium) difficile colitis: No longer a diarrhea associated infection.

BACKGROUND: Clostridioides difficile infection (CDI) is traditionally taught to be an antibiotic associated diarrheal infection. This diagnosis is based on the presence of clinical symptoms (usually defined as more than 3 watery, loose or unformed stool within 24 h) coupled with a diagnostic test. There is now a new presentation of CDI, including progression to toxic megacolon, in patients without diarrhea. METHODS: We report a case series of 9 surgical patients from a single institution who developed CDI without preceding diarrhea. RESULT: All 9 patients had CDI with positive laboratory testing for C. difficile toxin. They, however, presented with a lack of or minimal bowel movements. Six patients had rapid development of abdominal distention, 1 patient had a single episode of watery stool in 3 days, while the other 2 patients presented with constipation. Seven patients received stool softeners, suppositories and/or enemas for presumed constipation. Four patients had a mild course of infection and were successfully treated medically. The other 5 patients developed toxic megacolon, and eventually required total abdominal colectomy. Out of the 5 patients that required total colectomy, 2 expired. CONCLUSION: CDI must be suspected in patients who rapidly develop abdominal distention, vague abdominal complaints or change in bowel function even in the absence of diarrhea, especially if coupled with multi-system organ failure.

An intraluminal stent facilitates light-activated vascular anastomosis.

BACKGROUND: Photochemical tissue bonding (PTB) is a sutureless, light-activated technique that produces a watertight, microvascular repair with minimal inflammation compared to standard microsurgery. However, it is practically limited by the need for a clinically viable luminal support system. The aim of this study was to evaluate a hollow biocompatible stent to provide adequate luminal support to facilitate vascular anastomosis using the PTB technique. METHODS: Forty rats underwent unilateral femoral artery transection. Five rats were used to optimize the stent delivery method, and the remaining 35 rats were randomized into three groups: (1) standard suture repair with 10-0 nylon microsuture (SR), (2) standard suture repair over the stent (SR + S), or (3) PTB repair over stent (PTB + S). For the PTB group, a 2-mm overlapping cuff was painted with 0.1% (wt/vol) Rose Bengal then illuminated for 30 seconds on each side (532 nm, 0.5 W/cm, 30 J/cm). Anastomotic leak and vessel patency (immediate, 1 hour, and 1 week postoperatively) were assessed. RESULTS: Vessels in all three groups were patent immediately and at 1 hour postoperatively. After 1 week, all animals displayed patency in the SR group, while only 5 of 14 and 2 of 8 surviving animals had patent vessels in the PTB + S and SR + S groups, respectively. CONCLUSIONS: This study demonstrated successful use of an intraluminal stent for acute microvascular anastomosis using the PTB technique. However, the longer-term presence of the stent at the anastomotic site led to thrombosis in multiple cases. A rapidly dissolvable stent should facilitate a light-activated microvascular anastomosis with excellent long-term patency.

A light-activated amnion wrap strengthens colonic anastomosis and reduces peri-anastomotic adhesions.

BACKGROUND AND OBJECTIVE: Colonic anastomotic failure is a dreaded complication, and multiple surgical techniques have failed to eliminate it. Photochemical tissue bonding (PTB) is a method of sealing tissue surfaces by light-activated crosslinking. We evaluated if a human amniotic membrane (HAM), sealed over the anastomotic line by PTB, increases the anastomotic strength. STUDY DESIGN: Sprague-Dawley rats underwent midline laparotomy followed by surgical transection of the left colon. Animals were randomized to colonic anastomosis by one of the following methods (20 per group): single-layer continuous circumferential suture repair (SR); SR with a HAM wrap attached by suture (SR+ HAM-S); SR with HAM bonded photochemically over the anastomotic site using 532 nm light (SR+ HAM-PTB); approximation of the bowel ends with only three sutures and sealing with HAM-PTB (3+ HAM-PTB). A control group underwent laparotomy alone with no colon resection (NR). Sub-groups (n = 10) were sacrificed at days 3 and 7 post-operatively and adhesions were evaluated. A 6 cm section of colon was then removed and strength of anastomosis evaluated by burst pressure (BP) measurement. RESULTS: A fourfold increase in BP was observed in the SR+ HAM-PTB group compared to suture repair alone (94 ± 3 vs. 25 ± 8 mm Hg, P < 0.0001) at day 3. At day 7 the burst pressures were 165 ± 40 and 145 ± 31 mm Hg (P = 1), respectively. A significant decrease in peri-anastomotic adhesions was observed in the SR+ HAM-PTB group compared to the SR group at both time points (P < 0.001). CONCLUSION: Sealing sutured colonic anastomotic lines with HAM-PTB increases the early strength of the repair and reduces peri-anastomotic adhesions. Lasers Surg. Med. 48:530-537, 2016. © 2016 Wiley Periodicals, Inc.

Comprehensive evaluation of peripheral nerve regeneration in the acute healing phase using tissue clearing and optical microscopy in a rodent model.

Peripheral nerve injury (PNI), a common injury in both the civilian and military arenas, is usually associated with high healthcare costs and with patients enduring slow recovery times, diminished quality of life, and potential long-term disability. Patients with PNI typically undergo complex interventions but the factors that govern optimal response are not fully characterized. A fundamental understanding of the cellular and tissue-level events in the immediate postoperative period is essential for improving treatment and optimizing repair. Here, we demonstrate a comprehensive imaging approach to evaluate peripheral nerve axonal regeneration in a rodent PNI model using a tissue clearing method to improve depth penetration while preserving neural architecture. Sciatic nerve transaction and end-to-end repair were performed in both wild type and thy-1 GFP rats. The nerves were harvested at time points after repair before undergoing whole mount immunofluorescence staining and tissue clearing. By increasing the optic depth penetration, tissue clearing allowed the visualization and evaluation of Wallerian degeneration and nerve regrowth throughout entire sciatic nerves with subcellular resolution. The tissue clearing protocol did not affect immunofluorescence labeling and no observable decrease in the fluorescence signal was observed. Large-area, high-resolution tissue volumes could be quantified to provide structural and connectivity information not available from current gold-standard approaches for evaluating axonal regeneration following PNI. The results are suggestive of observed behavioral recovery in vivo after neurorrhaphy, providing a method of evaluating axonal regeneration following repair that can serve as an adjunct to current standard outcomes measurements. This study demonstrates that tissue clearing following whole mount immunofluorescence staining enables the complete visualization and quantitative evaluation of axons throughout nerves in a PNI model. The methods developed in this study could advance PNI research allowing both researchers and clinicians to further understand the individual events of axonal degeneration and regeneration on a multifaceted level.

A photoactivated nanofiber graft material for augmented Achilles tendon repair.

BACKGROUND AND OBJECTIVE: Suture repair of Achilles tendon rupture can cause infection, inflammation and scarring, while prolonged immobilization promotes adhesions to surrounding tissues and joint stiffness. Early mobilization can reduce complications provided the repair is strong enough to resist re-rupture. We have developed a biocompatible, photoactivated tendon wrap from electrospun silk (ES) to provide additional strength to the repair that could permit early mobilization, and act as a barrier to adhesion formation. STUDY DESIGN/MATERIAL AND METHODS: ES nanofiber mats were prepared by electrospinning. New Zealand white rabbits underwent surgical transection of the Achilles tendon and repair by: (a) SR: standard Kessler suture + epitendinous suture (5-0 vicryl). (b) ES/PTB: a single stay suture and a section of ES mat, stained with 0.1% Rose Bengal (RB), wrapped around the tendon and bonded with 532 nm light (0.3 W/cm(2) , 125 J/cm(2) ). (c) SR + ES/PTB: a combination of (a) and (b). Gross appearance, extent of adhesion formation and biomechanical properties of the repaired tendon were evaluated at Days 7, 14, or 28 post-operatively (n = 8 per group at each time point). RESULTS: Ultimate stress (US) and Young's modulus (E) in the SR group were not significantly different from the ES/PTB group at Days 7 (US, P = 0.85; E, P = 1), 14 (US, P = 0.054; E, P = 1), and 28 (US, P = 0.198; E, P = 0.12) post-operatively. Adhesions were considerably greater in the SR group compared to the ES/PTB group at Days 7 (P = 0.002), 14 (P < 0.0001), and 28 (P < 0.0001). The combination approach of SR + ES/PTB gave the best outcomes in terms of E at 7 (P < 0.016) and 14 days (P < 0.016) and reduced adhesions compared to SR at 7 (P < 0.0001) and 14 days (P < 0.0001), the latter suggesting a barrier function for the photobonded ES wrap. CONCLUSION: Photochemical sealing of a ES mat around the tendon repair site provides considerable benefit in Achilles tendon repair. Lasers Surg. Med. 44: 645-652, 2012. © 2012 Wiley Periodicals, Inc.