Extra-anatomic temporary intravascular shunting to assist with replantation of an amputated hand with prolonged ischemic time.

Although temporary intravascular shunting has been reported to assist with hand revascularization and replantation after traumatic amputation, most reports have described using ipsilateral upper limb inflow. We present a case of a traumatic hand amputation in a patient who had presented with 4 to 5 hours of warm ischemic time. Because the replantation team believed that extra-anatomic revascularization would be necessary, we performed a novel type of temporary intravascular shunting by connecting two arterial sheaths placed in the ulnar and superficial femoral arteries. This permitted the hand to be successfully replanted away from the inflow source and resulted in a good long-term functional outcome.

Reconstruction of Lower Extremity Defects Using the Serratus Anterior Free Flap: A Systematic Review and Retrospective Case Series.

BACKGROUND: Free tissue transfer is the most common modality for distal third lower extremity reconstruction, yet complication rates remain high. The serratus anterior muscle free flap, which can be harvested alone or as a chimeric flap, is a robust and reliable option that remains the primary modality for distal third lower extremity defects at our institution. The objective of this study was to perform a systematic review of lower extremity reconstruction with the serratus anterior free flap and provide a retrospective review of cases at our institution. METHODS: A systematic review of the literature was conducted using PubMed, Embase, and Cochrane Library (PROSPERO CRD42018110692). Articles reporting reconstruction of lower extremity and foot defects using serratus anterior free flaps in adults were included. A retrospective cohort study of serratus anterior free flaps was then performed from 2012 to 2018 at our institution. RESULTS: Thirty-seven articles meeting inclusion criteria provided data on 198 flaps: 125 (63%) serratus-only flaps and 73 (37%) chimeric flaps based on the subscapular axis. Among the serratus-only flaps, defects were primarily due to chronic wounds (51%) or acute infections (33%). Flap survival rate was 97%, and the major and minor complication rates were 5 and 9%, respectively. Of the 10 cases included in the case series, flap survival rate was 100%, there were no major complications, and the minor complication rate was 44%. The average time to flap healing was 95 days and average lower extremity functional scale score was 58/80 among five patients. CONCLUSION: Serratus anterior muscle free flaps are a versatile and reliable option for distal third lower extremity reconstruction.

Three-dimensional Printed Surgical Simulator for Kirschner Wire Placement in Hand Fractures.

Closed reduction and percutaneous pinning (CRPP) of hand fractures can be a deceptively challenging procedure that requires significant hands-on time to teach and learn. We created a realistic three-dimensional simulator that can be used for teaching junior residents the CRPP. Computer-aided design and computer-aided manufacturing (CAD/CAM) software was used to create a three-dimensional hand model incorporating several common hand fractures: Bennett's fracture, transverse fifth metacarpal neck, and transverse second proximal phalanx. Three-dimensional printing was used to create molds in which the bones and soft tissue were poured. A polyurethane foam was utilized for the bones with iron incorporated to render them radiopaque, whereas silicone of varying viscosities was used for the soft tissues. Five plastic surgery residents and 5 consultants evaluated the model. Individuals then completed an anonymous 12-question survey evaluating the model based on realism, educational utility, and overall usefulness. Survey responses obtained from both residents and consultants were strongly in favor of the simulator. Average realism was graded as 4.48/5 by residents and 4.68/5 by consultants. Average educational utility was graded as 5/5 by residents and 4.95/5 by consultants. Average overall usefulness was graded as 5/5 by both groups. We created an anatomically accurate and realistic simulator for CRPP of hand fractures that was low cost and easily reproducible. Initial feedback was encouraging in regard to realism, educational utility, and overall usefulness.

Biomechanical Analysis of Palmar Midcarpal Instability and Treatment by Partial Wrist Arthrodesis.

PURPOSE: To create a biomechanical model of palmar midcarpal instability by selective ligament sectioning and to analyze treatment by simulated partial wrist arthrodesis. METHODS: Nine fresh-frozen cadaver arms were moved through 3 servohydraulic actuated motions and 2 passive wrist mobilizations. The dorsal radiocarpal, triquetrohamate, scaphocapitate, and scaphotrapeziotrapezoid ligaments were sectioned to replicate palmar midcarpal instability. Kinematic data for the scaphoid, lunate, and triquetrum were recorded before and after ligament sectioning and again after simulated triquetrohamate arthrodesis (TqHA) and radiolunate arthrodesis (RLA). RESULTS: Following ligament sectioning, the model we created for palmar midcarpal instability was characterized by significant increases in (1) lunate angular velocity, (2) lunate flexion-extension, and (3) dorsal/volar motion of the capitate during dorsal/volar mobilizations. Simulated TqHA caused significantly more scaphoid flexion and less extension during the wrist radioulnar deviation motion. It also increased the amount of lunate and triquetral extension during wrist flexion-extension. Simulated RLA significantly reduced scaphoid flexion during both wrist radioulnar deviation and flexion-extension. CONCLUSIONS: Both simulated arthrodeses eliminate wrist clunking and may be of value in treating palmar midcarpal instability. However, simulated RLA reduces proximal row motion whereas simulated TqHA alters how the proximal row moves. Long-term clinical studies are needed to determine if these changes are detrimental. CLINICAL RELEVANCE: Palmar midcarpal instability is poorly understood, with most treatments based on pathomechanical assumptions. This study provides information that clinicians can use to design better treatment strategies for this unsolved condition.

Free tissue transfer for necrotizing fasciitis reconstruction: A case series.

BACKGROUND: Necrotizing fasciitis (NF) is a life-threatening infection requiring extensive debridement that may necessitate amputation. Free tissue transfer (FTT) is an option for reconstruction in difficult cases. Currently, only case reports have described FTT in the setting of NF, and comprehensive evidence on flap outcomes is lacking. The present study characterizes outcomes in patients with FTT following NF. METHODS: All patients admitted with NF between January 1, 2005 and December 31, 2011 to our level 1 burns/trauma referral center were retrospectively reviewed. RESULTS: No significant difference was found in patient demographics between FTT (n=12) and no FTT (n=212). Both groups had the same number of operations, same length of ICU stay, and length of hospitalization. The flaps used were 10 anterolateral thigh, 1 latissimus dorsi and 1 radial forearm. Recipient sites included: upper extremities (6), lower extremities (4), head/neck (1), and genitalia (1). No flap failures and no take-back operations were required. Upper extremities comprised 58.3% of FTT patients compared to 18.9% (p=0.004) in non-FTT patients. Flap operations occurred a mean of 11.6days post-admission with 1.1 operations prior to FTT. Mean FTT size was 213cm2. Flap complications included seroma (n=1), hematoma (n=1). Donor site complications included hematoma (n=1), exposed tendon (n=1) and necrosis (n=1). CONCLUSIONS: This study demonstrates that FTT provides a promising reconstructive option in the setting of NF without adversely affecting patient outcome.

What are the fluid requirements in toxic epidermal necrolysis?

Acute fluid requirements in toxic epidermal necrolysis (TEN) have neither been quantified nor reported. The purpose of this study was to examine acute fluid administration in TEN patients. A consecutive series of criteria and biopsy-confirmed cases of TEN admitted to our burn centre were selected for retrospective analysis. Charts were reviewed for demographic and resuscitation variables for the first (D0), second (D1), and third (D2) 24-hour periods after burn center admission. Twenty-one TEN cases were available for study, with a mean epidermal detachment of 53 +/- 24% TBSA. Mortality was 29%, with all deaths occurring after the study period. Average crystalloid volumes decreased from D0 (2.2 +/- 1.5 ml/kg/%TBSA) through D1 (1.6 +/- 1.1 ml/kg/%TBSA) and D2 (1.4 +/- 1.0 ml/kg/%TBSA), whereas urine output increased from D0 (1.3 +/- 0.9 ml/kg/hr) through D1 (1.4 +/- 0.9 ml/kg/hr) and D2 (1.8 +/- 1.1 ml/kg/hr). Worst base deficit (BD) corrected significantly from D0 to D1 (P = .01) and from D1 to D2 (P = .002). There was no correlation between daily crystalloid volumes and %TBSA detachment. Nonsurvivors had significantly higher severity-of-illness score for TEN and 24-hour mean and worst BDs than survivors, but did not require significantly more crystalloid or display lower urine outputs. Initial provision of approximately 2 ml/kg/%TBSA epidermal detachment to patients with TEN resulted in more than adequate urine output and significant correction of the BD. We emphasize that these data do not represent a resuscitation formula but rather a guideline for initial fluid administration, which should then be titrated to the patient's response.

Development of normal retinal organization depends on Sonic hedgehog signaling from ganglion cells.

The adult retina is organized into three cellular layers--an outer photoreceptor, a middle interneuron and an inner retinal ganglion cell (RGC) layer. Although the retinal pigment epithelium (RPE) and Müller cells are important in the establishment and maintenance of this organization, the signals involved are unknown. Here we show that Sonic hedgehog signaling from RGCs is required for the normal laminar organization in the vertebrate retina.