Peter I. Tsai

Motor Evoked Potentials in Thoracoabdominal Aortic Surgery: CON

Thoracoabdominal aortic aneurysms (TAAAs) have a dismal natural history that frequently necessitates surgical repair, but such repairs sometimes result in paraplegia and paraparesis. To reduce the risk of these complications, intraoperative monitoring of spinal cord motor evoked potentials (MEPs) can be used to guide TAAA repair procedures and may potentially minimize spinal cord ischemia. However, the use of MEP monitoring techniques requires important changes to anesthetic management, entails certain risks, and has important contraindications.

Overcoming challenges of endovascular treatment of complex subclavian and axillary artery injuries in hypotensive patients.

A subclavian and axillary artery injuries are located within a transition zone at the junction between the thorax, neck, and upper extremity, contained within a surrounding skeletal cage. Open exposure of these vessels through supraclavicular and infraclavicular incisions, sternotomy, and thoracotomy can be challenging and morbid. The application of endovascular therapy aims to overcome the drawbacks of open surgical management and offers an attractive alternative for injuries to these vessels. Yet, even up until recently, barriers to endovascular management of these injuries included hemodynamic instability, complete vessel transection, and vessel thrombosis. With this report, we aimed to describe an endovascular technique our service developed to overcome the previously mentioned barriers and report our experience with endovascular repair of complex subclavian and axillary artery injuries in hypotensive patients.

Challenges in the Diagnosis and Management of Unusual Presentations of Blunt Injury to the Ascending Aorta and Aortic Sinuses

BACKGROUND Blunt injury to the thoracic aorta continues to carry significant mortality and the diagnostic algorithms are evolving as new technology is developed. With improved pre-hospital care, patients with unusual blunt injuries to the aorta may survive to evaluation. While current algorithms for screening focus on the more common blunt injuries to the descending thoracic aorta, our service has seen four injuries to the ascending aorta that have had unusual presentations and presented significant challenges in their management. METHODS Retrospective chart review based on a cardiovascular injury database. RESULTS Four patients were identified who survived to hospitalization with an injury to the ascending thoracic aorta. Two were to the ascending aorta and two to the aortic sinuses. Two presented with closed head injury complicating management. One patient presented with aortic valve insufficiency. Motion artifacts at the aortic sinus made screening by CT challenging. These injuries were managed with primary repair (1), tube graft replacement (2), and aortic root replacement with reimplantation of the coronaries (1), all with cardiopulmonary bypass. CONCLUSION Injuries to the ascending aorta and aortic sinus that survive to evaluation present unique challenges to the screening algorithms. All required cardiopulmonary bypass for repair and potentially complex reconstructions with management decisions affected by the presence of associated injuries. New methodologies such as CT scan gated to cardiac motion may offer higher resolution in this area.

Endovascular repair of traumatic aortic injury using a custom fenestrated endograft to preserve the left subclavian artery.

Purpose: To describe the use of custom fenestrated endografts to preserve left subclavian artery (SCA) flow when requiring coverage during endovascular repair of blunt aortic injury (BAI). Case Report: A 39-year-old male involved in a motor vehicle accident sustained injuries including intracranial hemorrhage, BAI, and extremity fractures. Immediate neurosurgical intervention was required. Once neurologically stabilized, endovascular repair was performed with a commercially available device modified with a custom fenestration to preserve flow into the left SCA. Serial follow-up CT angiography (CTA) demonstrates satisfactory repair with prograde left SCA flow and no evidence of endoleak. Conclusion: Left SCA coverage is often required for successful endovascular repair of BAI. A subgroup of patients who undergo left SCA coverage will require revascularization. The use of custom fenestrated endografts for preserving left SCA during thoracic endovascular aortic repair (TEVAR) for BAI is an innovative and feasible option in patients who require revascularization.

Intravascular ultrasound enhanced aortic sizing for endovascular treatment of blunt aortic injury.

BACKGROUND Blunt aortic injury (BAI) in young patients with a compliant aorta and evolving hyperdynamic physiology may result in significant variation in aortic diameter during the cardiac cycle. Intravascular ultrasound (IVUS) may be useful to detect real-time variations in aortic diameters for more reliable sizing in patients undergoing thoracic endovascular aortic repair (TEVAR) of BAI. METHODS This is a single-institution retrospective study of patients who underwent TEVAR for BAI in a Level 1 trauma center from January 2004 to January 2014. Patients underwent either trauma survey computed tomography (CT) alone (CT group) or IVUS and CT (IVUS group). We compared predeployment aortic measurements, implanted device size, landing zones, and repair outcomes between the groups. RESULTS Forty-one patients underwent TEVAR for BAI: 28 were in the CT group and 13 in the IVUS group. Left subclavian artery (LSCA) coverage was performed in 50% (CT group) and 38% (IVUS group) of patients. CT-based median aortic diameter was similar in both groups (20.5 mm in the CT group vs. 19.0 mm in the IVUS group, p = 0.374). The median proximal diameter of the proximal device implanted was 26 mm in the CT group and 24 mm in the IVUS group (p = 0.329), which resulted in oversizing of 25.7% and 13.7% (p < 0.001), respectively. The implanted device was changed in 6 of 13 patients and in 4 of 5 patients in which the LSCA was covered because of IVUS measured-diameters. Graft extension proximal to the LSCA resulted in greater differences between the CT and IVUS measurements of the proximal aorta than if the graft was isolated to the descending aorta (18.8% vs. 5.57%, p = 0.005). Technical success of repair for both groups was 100%; no secondary interventions were required in either group. CONCLUSION In combination with CT, IVUS provides important separate sizing information at the point of implantation for more accurate device selection, eliminating need for a repeat CT. LEVEL OF EVIDENCE Therapeutic study, level IV.

Endovascular therapy for overcoming challenges presented with blunt abdominal aortic injury.

Blunt abdominal aortic injury (BAAI) is a rare and lethal injury requiring surgical management. Injury patterns can be complex and surgical strategy should accommodate specific case circumstances. Endovascular solutions appear appropriate and preferred in certain cases of BAAI, which, however, may not be applicable due to device limitations in regard to patient anatomy and limited operating room capability. However, endovascular therapy can be pursued with limited fluoroscopy capability and consumable availability providing a solution that is expeditious and effective for select cases of BAAI.

Takayasu Arteritis Complicating Pregnancy in Adolescence

Pregnant adolescent patients afflicted with Takayasu arteritis represent a clinical entity not seen by many. The care of such patients is often managed by multidisciplinary teams, where vascular surgeons are asked to provide input on cardiovascular implications during and after a pregnant state. Knowledge and understanding of the interaction between the two conditions allows for well-informed decision making and favorable outcomes with pregnancy, as well as proper long-term follow-up and care with appropriate clinicians.

Cardiac arrest upon induction of general anesthesia: transesophageal echocardiography-assisted diagnosis of impending paradoxical embolus.

CARDIAC arrest occurring upon the induction of general anesthesia in an otherwise healthy patient is distinctly rare. It is even more unusual to discover its etiology to be an impending paradoxical embolus (IPE). We present a case in which the timely use of transesophageal echocardiography (TEE), implemented during the course of cardiopulmonary resuscitation, revealed a large transatrial thromboembolus which had been trapped in transit through a patent foramen ovale.

Operative challenges in management of concurrent interrupted aortic arch and descending thoracic aortic aneurysm

Interrupted aortic arch is a rare finding in the adult patient. This condition in combination with a descending thoracic aortic aneurysm is an even more exceptional occurrence. Surgical management includes open, endovascular, and hybrid options. We present the case of a 57-year-old man with interrupted aortic arch and concomitant descending thoracic aortic aneurysm, review characterization of this entity, and discuss management options with consideration to associated risks.

Commentary on: Impact of Advanced Practice Providers (Nurse Practitioners and Physician Assistants) on Surgical Residents' Critical Care Experience.

DOI of original article: http://dx.doi.org/1 * Corresponding author. Division of Cardioth Baylor Plaza, MC 390 Houston, TX 77030. Te E-mail address: tsai@bcm.edu. 0022-4804/