A long-term survival rat model of spinal cord ischemia injury: Thoracic aortic occlusion combined with aortic bypass circulation

Objective This study aims to investigate the methods for rat spinal cord ischemia injury models with a high long-term survival rate. Methods The rats were divided into three groups: the treatment group, the control group, and the sham operation group. The treatment group had a blocked thoracic aorta (landing zone 3 by Ishimaru – T11) + aortic bypass circulation for 20 min. In the control group, the thoracic aorta at the landing zone 3 was blocked for 20 min. In the sham operation group, only thoracotomy without thoracic aortic occlusion was performed. The mean arterial blood pressure (MABP) of the thoracic aorta and caudal artery before and after thoracic aortic occlusion was monitored intraoperatively. Spinal cord function was monitored by a transcranial motor evoked potential (Tc-MEP) during the operation. Spinal cord function was evaluated by the BBB scale (Basso, Beattie, & Bresnahan locomotor rating scale) scores at multiple postoperative time points. The spinal cord sections of the rats were observed for 7 days after surgery, and the survival curves were analyzed for 28 days after surgery. Results After aortic occlusion, the MABP of thoracic aorta decreased to 6% of that before occlusion, and the MABP of caudal artery decreased to 63% of that before occlusion in the treatment group. In the control group, the MABP of both thoracic aorta and caudal artery decreased to 19% of that before occlusion. The Tc-MEP waveform of the treatment group disappeared after 6 min, and that of the control group disappeared after 8 min until the end of surgery. There was no change in the Tc-MEP waveform in the sham operation group. The BBB score of the treatment group decreased more obviously than the control group, and there was a significant difference. There was no decrease in the sham group. Spinal cord sections showed a large number of degeneration and necrosis of neurons, infiltration of inflammatory cells, and proliferation of surrounding glial cells in the treatment group. In the control group, multiple neurons were necrotic. The histology of the sham operation group was normal. The 28-day survival rate of the treatment group was 73.3%, which was higher than the control group (40.0%), and there was a significant difference ( p < 0.05). Conclusion Thoracic aortic occlusion combined with aortic bypass is an effective modeling method for rats with accurate modeling effects and high long-term survival rates.

Role of Extra-anatomic Ascending to Descending Bypass in Complex Thoracic Aortic Pathology

Complex pathology of the distal arch and proximal descending thoracic aorta is usually approached by stent endografting or in situ graft replacement. Oftentimes, these options are not feasible due to unfavorable anatomy, multiple previous procedures, active infection, or presence of concomitant cardiac disease. Thoracic aortic extra-anatomic bypass, as part of an open surgical strategy, is a useful and often the only curative option left for the treatment in these patients. Herein, we describe two cases that illustrate the utility of extra-anatomic thoracic aortic bypass for complex aortic disease.

Mid-term Patency of the Great Saphenous Bypass to Aorta vs. Non-aortic Arteries in Stanford Type A Aortic Dissection Surgery With Concomitant CABG

Background: Stanford type A aortic dissection (STAAD) is often associated with coronary artery problems requiring coronary artery bypass grafting (CABG). However, the prognosis of different proximal graft locations remains unclear.Methods: From May 2015 to April 2020, 62 patients with acute STAAD who underwent aortic surgery concomitant with CABG were enrolled in our study. Aortic bypass was defined as connecting the proximal end of the vein bridge to the artificial aorta (SVG-AO); non-aortic bypass was defined as connecting the proximal end of the vein bridge to a non-aorta vessel, including left subclavian artery, left common carotid artery, and right brachiocephalic artery (non-SVG-AO). We compared early- and mid-term results between patients in the above two groups. Early results included death and bleeding, and mid-term results graft patency, aortic-related events, and bleeding. Grafts were evaluated by post-operative coronary computed tomography angiography. According to the Fitzgibbon classification, grade A (graft stenosis &lt;50%) is considered a patent graft. Univariate and multivariate analyses were performed to assess differences between aortic and non-aortic bypass in STAAD.Results: SVG-AO and non-SVG-AO were performed in 15 and 47 patients, respectively. There was no significant difference in death (log-rank test, p = 0.426) or bleeding (p = 0.766) between the two groups in the short term. One year of follow-up was completed in 37 patients (eight in the SVG-AO group and 29 in the non-SVG-AO group), among which 14/15 (93.3%) grafts were patent in the SVG-AO group and 32/33 (97.0%) grafts in the non-SVG-AO at 1 week, without a significant difference (p = 0.532). At 3 months, 12/13 (92.3%) grafts were patent in the SVG-AO group and 16/32 (50.0%) grafts in the non-SVG-AO, with a significant difference (p = 0.015), and 12/13 (92.3%) grafts in the SVG-AO group and 15/32 (46.9%) grafts in the non-SVG-AO group were patents, with a significant difference. Multivariate analysis showed proximal aortic bypass and dual anticoagulation to be protective factors for the 1-year patency of grafts.Conclusion: In patients requiring aortic dissection surgery with concomitant CABG, no differencess' between SVG-AO and SVG-non-AO in early outcomes were detected, but SVG-AO may have higher mid-term patency.

Off-Pump Aortic Bypass for Hypoplastic Arch and Aortic Coarctation Via Anterolateral Thoracotomy

We report the case of a 21-year-old woman who was referred with uncontrolled hypertension. Computed tomography angiography revealed aortic arch hypoplasia and severe aortic coarctation. An off-pump ascending-to-descending aortic bypass surgery using synthetic graft was performed via left anterolateral thoracotomy. The patient recovered well and was discharged home uneventfully after five days. This procedure was performed without touching the head vessels or any collateral vessels. We consider this a safe and less invasive alternative technique for adult coarctation patients who have aortic hypoplasia or interrupted aorta.

Extra-anatomic aortic bypass combined with Bentall procedure for a complex coarctation and aortic aneurysm

Surgical treatment of complex coarctation is still a challenge. We performed extra-anatomic aortic bypass and Bentall procedure for a 10-year old boy diagnosed with critical aortic coarctation, aortic aneurysm, and severe aortic valve insufficiency who previously received Switch procedure. The patient is alive and well 52 months postoperatively with a satisfactory result. Extra-anatomic aortic bypass is a safe and effective procedure for patients with complex coarctation.

Treatment of middle aortic syndrome with thoraco-abdominal aortic bypass grafting assisted by endoscope in adult

Middle aortic syndrome (MAS) is a rare disease characterized by distal thoracic aorta or abdominal aorta coarctation, and thoraco-abdominal aortic bypass grafting is an effective treatment for this condition. However, significant trauma is associated with the conventional surgical approach. We report a 26-year-old woman with MAS who presented with hypertension and needed thoraco-abdominal bypass grafting. In this operation, we adopted the endoscopic technique to improve the conventional surgical approach (reduce the incision). This case report shows that it is safe and feasible to use an endoscopic technique to reduce the trauma during this kind of operation, and provides a reference for similar treatments.

Unusual case of dystrophic calcification and thrombosis of an extra-anatomical graft in a patient with Takayasu’s arteritis

We report the case of a thrombotic occlusion of an extra-anatomical aortic bypass graft performed 37 years ago in a 46-year-old male with Takayasu’s arteritis. He presented with uncontrolled upper body hypertension, claudication pain in both the lower limbs, and kidney dysfunction which returned to normal post-surgery. On table we found a pseudoaneurysm at the proximal anastomosis along with calcification of the capsular tissue surrounding the graft. We attempt to explain the mechanism behind the graft occlusion, along with management of this late surgical complication which has not been described in the existing literature.