An Approach for Cognitive Evaluation and Management of Grade 5 Arteriovenous Malformation-Associated Thalamic Dementia: A Case Report and Literature Review

The clinical approach to managing high-grade arteriovenous malformations (AVMs) has been challenging due to its various presentations, surgical risk of complications, and impact on patients' quality of life. We report a case of a 57-year-old female who experienced recurrent seizures and progressive cognitive decline secondary to a grade 5 cerebellar AVM. We reviewed the patient's presentation and clinical course. We also searched the literature for studies, reviews, and case reports involving the management of high-grade AVMs. We outline our recommendations on how to approach these cases after a review of the currently available treatment options.

Rodent Model for Orthotopic Implantation of Engineered Liver Devices

This study presents a novel surgical model developed to provide hematological support for implanted cellularized devices augmenting or replacing liver tissue function. Advances in bioengineering provide tools and materials to create living tissue replacements designed to restore that lost to disease, trauma, or congenital deformity. Such substitutes are often assembled and matured in vitro and need an immediate blood supply upon implantation, necessitating the development of supporting protocols. Animal translational models are required for continued development of engineered structures before clinical implementation, with rodent models often playing an essential early role. Our long-term goal has been generation of living tissue to provide liver function, utilizing advances in additive manufacturing technology to create 3D structures with intrinsic micron to millimeter scale channels modeled on natural vasculature. The surgical protocol developed enables testing various design iterations in vivo by anastomosis to the host rat vasculature. Lobation of rodent liver facilitates partial hepatectomy and repurposing the remaining vasculature to support implanted engineered tissue. Removal of the left lateral lobe exposes the underlying hepatic vasculature and can create space for a device. A shunt is created from the left portal vein to the left hepatic vein by cannulating each with separate silicone tubing. The device is then integrated into the shunt by connecting its inflow and outflow ports to the tubing and reestablishing blood flow. Sustained anticoagulation is maintained with an implanted osmotic pump. In our studies, animals were freely mobile after implantation; devices remained patent while maintaining blood flow through their millifluidic channels. This vascular anastomosis model has been greatly refined during the process of performing over 200 implantation procedures. We anticipate that the model described herein will find utility in developing preclinical translational protocols for evaluation of engineered liver tissue. Impact statement Tissue and organ transplantation are often the best clinically effective treatments for a variety of human ailments. However, the availability of suitable donor organs remains a critical problem. Advances in biotechnology hold potential in alleviating shortages, yet further work is required to surgically integrate large engineered tissues to host vasculature. Improved animal models such as the one described are valuable tools to support continued development and evaluation of novel therapies.

Vascular Shunt for Small Vessel Trauma in a Polytrauma Patient

A 15-year-old male patient presented with multiple gunshot injuries. The patient underwent emergency lifesaving exploratory laparotomy and subsequently needed repair of his left upper limb ulnar artery injury. A shunt helped restore blood flow to the hand in a setting of damage control surgery in an exsanguinating patient with an ulnar artery injury having a massive disruption. After resuscitation, the patient underwent definitive repair of the artery using a vein interposition graft.

Distributive Shock in a Neonate with Diffuse Infantile Hepatic Hemangioma

BACKGROUND

Hemangiomas are common cutaneous findings on healthy infants. These vascular malformations are generally benign, though in rare circumstances they can potentially be fatal. This is particularly true when the hemangiomas are large or numerous and occurring in visceral organs. Previously unrecognized visceral hemangiomas are part of the differential for any neonate presenting unexpectedly in shock.

CASE REPORT

A 10-day-old neonate presented to the pediatric emergency department with difficulty breathing. On examination, he appeared to be in respiratory distress and in shock. Echocardiography showed cardiomegaly, and an abdominal ultrasound showed a massive and heterogeneous liver. Magnetic resonance imagine performed after stabilization in the pediatric intensive care unit verified the presence of diffuse infantile hepatic hemangiomas. This case demonstrates how numerous visceral hemangiomas can generate high-volume vascular steal, distributive shock, and cardiac failure. Our patient was subsequently noted to have bruits over his liver. WHY AN EMERGENCY PHYSICIAN SHOULD BE AWARE OF THIS?: Diffuse hemangiomas and arteriovenous malformations are rare causes of extrinsic cardiogenic shock in the neonate. Targeted palpation of an enlarged liver or auscultation of a right upper quadrant bruit can raise suspicion of this diagnosis.

Magnetic Resonance Imaging-Guided Transcatheter Cavopulmonary Shunt

OBJECTIVES

The aim of this study was to test the hypothesis that real-time magnetic resonance imaging (MRI) would enable closed-chest percutaneous cavopulmonary anastomosis and shunt by facilitating needle guidance along a curvilinear trajectory, around critical structures, and between a superior vena cava "donor" vessel and a pulmonary artery "target."

BACKGROUND

Children with single-ventricle physiology require multiple open heart operations for palliation, including sternotomies and cardiopulmonary bypass. The reduced morbidity of a catheter-based approach would be attractive.

METHODS

Fifteen naive swine underwent transcatheter cavopulmonary anastomosis and shunt creation under 1.5-T MRI guidance. An MRI antenna-needle was advanced from the superior vena cava into the target pulmonary artery bifurcation using real-time MRI guidance. In 10 animals, balloon-expanded off-the-shelf endografts secured a proximal end-to-end caval anastomosis and a distal end-to-side pulmonary anastomosis that preserved blood flow to both branch pulmonary arteries. In 5 animals, this was achieved with a novel, purpose-built, self-expanding device.

RESULTS

Real-time MRI needle access of target vessels (pulmonary artery), endograft delivery, and superior vena cava shunt to pulmonary arteries were successful in all animals. All survived the procedure without complications. Intraprocedural real-time MRI, post-procedural MRI, x-ray angiography, computed tomography, and necropsy showed patent shunts with bidirectional pulmonary artery blood flow.

CONCLUSIONS

MRI guidance enabled a complex, closed-chest, beating-heart, pediatric, transcatheter structural heart procedure. In this study, MRI guided trajectory planning and reproducible, reliable bidirectional cavopulmonary shunt creation.