Successful Extension of Vascularized Composite Allograft Perfusion Cold Storage to 24 h in a Rat Hindlimb Transplant Model.

Background: Vascularized composite allograft transplantation is a treatment option for complex tissue injuries; however, ischemia reperfusion injury and high acute rejection rates remain a challenge. Hypothermic machine perfusion using acellular storage perfusate is a potential solution. This study evaluated the University of Wisconsin Kidney Preservation Solution-1 (KPS-1) compared with normal saline (NS) for preservation of donor rat hindlimbs subjected to 24 h of ex vivo perfusion cold storage. Methods: Hindlimbs were subjected to 24-h perfusion cold storage with heparinized KPS-1 (n = 6) or heparinized NS (n = 6). Flow, resistance, and pH were measured continuously. At the end of the 24-h period, tissue was collected for histological analysis of edema and apoptosis. Results: KPS-1 perfused limbs showed significantly less edema than the NS group, as evidenced by lower limb weight gain (P < 0.001) and less interfascicular space (P < 0.001). KPS-perfused muscle had significantly less cell death than NS-perfused muscle based on terminal deoxynucleotidyl transferase dUTP nick-end labeling (P < 0.001) and cleaved caspase-3 staining (P = 0.045). During hypothermic machine perfusion, a significant decrease in pH over time was detected in both groups, with a significantly greater decline in pH in the KPS-1 group than in the NS group. There were no significant differences overall and over time in flow rate or vascular resistance between the KPS and NS groups. Conclusions: Perfusion with KPS-1 can successfully extend vascularized composite allograft perfusion cold storage for 24 h in a rat hindlimb model without significant edema or cell death.

Analysis of Postoperative Distal Radius Fracture Outcomes in the Setting of Osteopenia and Osteoporosis for Patients with Comorbid Conditions.

Purpose: Distal radius fractures (DRFs) are among the most common orthopedic injuries, especially in the elderly. A wide variety of approaches have been advocated as successful treatment modalities; yet, there remains variability in practice patterns of DRF in patients with osteoporosis and osteopenia. Using large data set analysis, we sought to determine the risk profile of operative fixation of DRF in patients with low bone mineral density. Methods: A commercially available health care database, PearlDiver, was queried for all patients who underwent open reduction internal fixation of DRFs between 2010 and 2020. The study population was divided into groups based on the presence or absence of osteopenia or osteoporosis and was further classified by patients who were receiving bisphosphonate therapy. Complication rates were calculated, including rates of malunion, surgical site infection, osteomyelitis, hardware failure, and hardware removal. Five-year future fragility fractures were defined in hip, vertebrae, humerus, and wrist fractures. Chi-square analysis and logistic regression were performed to determine an association between these comorbidities and various postoperative complications. Results: A total of 152,926 patients underwent open reduction internal fixation of a DRF during the study period. Chi-square analysis of major complications at 3 months showed a statistically significant increase in malunion in patients with osteopenia (P = .05) and patients with osteoporosis (P = .05) who underwent open reduction internal fixation. Logistic regression analysis at 12 months after surgery demonstrated that osteopenia was associated with an increased risk of hardware failure (P < .0001), hardware removal (P < .0001), surgical site infection (P < .0001), and malunion (P = .004). Osteoporosis was associated with a significantly increased risk of hardware failure (P = .01), surgical site infection (P < .0001), and malunion (P < .0001). Conclusions: We demonstrated, using large data set analysis, that DRF patients with osteopenia and osteoporosis are predicted to be at increased risk of multiple postoperative complications, and thus, bone density should be strongly considered in treatment planning for these patients. Type of study/level of evidence: Prognostic III.

Unusual Volar Pulp Location of Glomus Tumor.

Glomus tumors are benign, painful growths originating from glomus bodies and comprise just 1% of tumors arising in the hand, with fewer than 10% in the volar pulp of digits. Hallmark symptoms of glomus tumors include hypersensitivity to cold, heightened pinprick sensitivity, and paroxysmal pain. We report a 72-year-old, right-hand dominant man who presented with pain in the left middle finger, localized to the tip. The fingertip was incredibly sensitive to touch, and his pain increased at night. He reported no recollection of trauma. Palpation of the finger revealed no mass, although it did indicate a focal point of pain within the distal pulp of the digit. Magnetic resonance imaging of the left hand revealed a round 7.0 × 4.0 × 6.0-mm soft tissue lesion along the volar ulnar aspect of the distal third digit. An incision was made in the mid-axial plane, circumscribing and removing the mass bluntly. It was a tan-yellow, soft tissue nodule of 0.8-cm in diameter without stalk or adherences to joints. Pathology revealed the mass was a glomus tumor. Symptoms improved on removal, and he healed without complication. Glomus tumors in the volar digital pulp can be difficult to diagnose. However, the presence of localized pain in the fingertip was reason to consider glomus tumor and proceed with treatment. Complete surgical removal of a glomus tumor is necessary to resolve symptoms and prevent recurrence.

Total Human Eye Allotransplantation: Developing Surgical Protocols for Donor and Recipient Procedures.

BACKGROUND: Vascularized composite allotransplantation of the eye is an appealing, novel method for reconstruction of the nonfunctioning eye. The authors' group has established the first orthotopic model for eye transplantation in the rat. With advancements in immunomodulation strategies together with new therapies in neuroregeneration, parallel development of human surgical protocols is vital for ensuring momentum toward eye transplantation in actual patients. METHODS: Cadaveric donor tissue harvest (n = 8) was performed with orbital exenteration, combined open craniotomy, and endonasal approach to ligate the ophthalmic artery with a cuff of paraclival internal carotid artery, for transection of the optic nerve at the optic chiasm and transection of cranial nerves III to VI and the superior ophthalmic vein at the cavernous sinus. Candidate recipient vessels (superficial temporal/internal maxillary/facial artery and superficial temporal/facial vein) were exposed. Vein grafts were required for all anastomoses. Donor tissue was secured in recipient orbits followed by sequential venous and arterial anastomoses and nerve coaptation. Pedicle lengths and calibers were measured. All steps were timed, photographed, video recorded, and critically analyzed after each operative session. RESULTS: The technical feasibility of cadaveric donor procurement and transplantation to cadaveric recipient was established. Mean measurements included optic nerve length (39 mm) and caliber (5 mm), donor artery length (33 mm) and caliber (3 mm), and superior ophthalmic vein length (15 mm) and caliber (0.5 mm). Recipient superficial temporal, internal maxillary artery, and facial artery calibers were 0.8, 2, and 2 mm, respectively; and superior temporal and facial vein calibers were 0.8 and 2.5 mm, respectively. CONCLUSION: This surgical protocol serves as a benchmark for optimization of technique, large-animal model development, and ultimately potentiating the possibility of vision restoration transplantation surgery. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Clinical Considerations for Vascularized Composite Allotransplantation of the Eye.

Vascularized composite allotransplantation represents a potential shift in approaches to reconstruction of complex defects resulting from congenital differences as well as trauma and other acquired pathology. Given the highly specialized function of the eye and its unique anatomical components, vascularized composite allotransplantation of the eye is an appealing method for restoration, replacement, and reconstruction of the nonfunctioning eye. Herein, we describe conventional treatments for eye restoration and their shortcomings as well as recent research and events that have brought eye transplantation closer to a potential clinical reality. In this article, we outline some potential considerations in patient selection, donor facial tissue procurement, eye tissue implantation, surgical procedure, and potential for functional outcomes.