Management of segmental intercostal and lumbar arteries during descending and thoracoabdominal aneurysm repairs

Selective Angiography to Detect Anterior Spinal Artery Stenosis in Thoracic Ossification of the Posterior Longitudinal Ligament

Study Design

Single-center prospective study.

Purpose

To investigate anterior spinal artery (ASA) status using preoperative selective angiography in patients undergoing surgery for thoracic ossification of the posterior longitudinal ligament (T-OPLL).

Overview of Literature

Surgery for T-OPLL has a high risk of neurological complications, which might be associated with insufficient spinal cord blood flow.

Methods

This study prospectively examined nine T-OPLL patients who underwent posterior thoracic decompression with kyphosis correction and instrumented fusion at Hamamatsu University School of Medicine between 2017 and 2019. All underwent preoperative selective angiography to detect and evaluate the Adamkiewicz artery and ASA. Intraoperative neuromonitoring and Doppler ultrasonography were performed to analyze neurological complications and spinal cord blood flow.

Results

All nine patients showed ASA stenosis in the area of T-OPLL. In all patients, the Adamkiewicz artery was located between T7 and L2 and the area of ASA stenosis corresponded to the level of T-OPLL and greatest spinal cord compression; intraoperative Doppler ultrasonography confirmed the ASA defect at the same spinal level. The number of spinal levels from the Adamkiewicz artery to the most compressive OPLL lesion was greater in the two patients who developed postoperative neurological deficit compared to those who did not (5.5 vs. 2.3, p=0.014).

Conclusions

This is the first study to report detection of ASA stenosis in patients with T-OPLL. Maintaining spinal cord blood flow is important in these patients to avoid neurological deterioration.

Anatomical variations of lumbar arteries and their clinical implications: a cadaveric study

Lumbar arteries arise from the abdominal aorta. Some abdominal and spinal surgeries can damage these arteries, and that can lead to serious consequences. This study aimed at studying the types and frequencies of variations of lumbar vasculature. We dissected both sides of 109 adult human cadavers and studied the variations of lumbar vasculature. Age range was 43–90 years. Fifty-seven percent were males and 43% were females. The number of lumbar arteries arising from either side of the abdominal aorta varied between 3 and 5 pairs. The lumbar arteries arose from a common single stem in 12% of the cadavers. The third and fourth pairs of lumbar arteries arose from a common single stem in 3% and 11% of cadavers, respectively, and the first and second pairs of lumbar arteries arose from a common single stem in 1% and 2% of cadavers, respectively. The first and second lumbar arteries on the right side traveled anterior to the right crus of the diaphragm in 7% and 8% of cadavers, respectively. There were several variations with regard to the number, origin from the abdominal aorta, and pathway of lumbar arteries from what is described in the literature.

Examination of intercostal arteries with transthoracic Doppler sonography

OBJECTIVE

There has been no study on the measurement of blood flow of the intercostal artery (ICA) or lumbar artery (LA) with the use of transthoracic Doppler sonography. Here, the method of the ICA depiction and flow measurement were described, and we suggested the clinical usage of this method.

METHODS

Twelve healthy subjects were examined. The performance of transthoracic Doppler sonography was approached from the back on lateral decubitus position. The intercostal artery was depicted by two-dimension mode with color flow, and the inner diameter was measured. Peak systolic velocity (PSV), end-diastolic velocity (EDV), velocity-time integral (VTI), and heart rate (HR) were measured with pulsed Doppler, and the blood flow was calculated.

RESULTS

Bilateral ICAs and LAs from Th4 to L4 were measurable with this method. The PSV of Lt Th9 was the fastest at 43.3 +/- 10.1 cm/sec and the PSV of the ICAs gradually decreased as distance from Th9 increased. As for the flow volume, the left Th11 was the greatest at 99.7 mL/min, and the flow volume of the ICA gradually decreased as distance from Th11 increased. The velocity and blood flow of right ICA tended to be lower than the left in the same spinal level.

CONCLUSIONS

Evaluation technique of serial ICAs and LAs was shown. We think that it may be a clinically useful method in the study of spinal cord circulation in the repair of cases of descending thoracic or thoracoabdominal aortic aneurysm.

MR angiography and CT angiography of the artery of Adamkiewicz: noninvasive preoperative assessment of thoracoabdominal aortic aneurysm

It is important to identify the artery of Adamkiewicz in patients with thoracoabdominal aortic aneurysm to aid in surgical planning and to prevent postoperative paraplegia or paraparesis. However, the artery of Adamkiewicz is difficult to visualize and impossible or very dangerous to evaluate with selective intercostal or lumbar angiography. The feasibility, advantages, and limitations of magnetic resonance (MR) angiography and computed tomographic (CT) angiography in the preoperative assessment of the artery of Adamkiewicz were evaluated in 30 patients with thoracoabdominal aortic aneurysm. Initial results indicate that MR angiography and CT angiography are safe, effective, noninvasive procedures that allow clear visualization of the artery of Adamkiewicz by providing detailed depiction of the vascular anatomy from the aorta to the anterior spinal artery. However, further studies will be needed to assess the efficacy of these modalities in decreasing surgical risk.

Aspects of the spinal cord circulation as assessed by intrathecal oxygen tension monitoring during various arterial interruptions in the pig

OBJECTIVE

We sought to study the effect of various modes of interruption of the spinal cord blood supply on intrathecal oxygenation.

METHODS

In 24 pigs intrathecal PO (2), PCO (2), and pH were continuously monitored with a multiparameter catheter (Paratrend 7, Biomedical Sensors; Diametrics Medical, Inc, St Paul, Minn) during and after aortic crossclamping or selective interruption of segmental arteries and proximal collateral circulation.

RESULTS

Proximal aortic clamping (n = 6) produced complete ischemia, whereas a second clamp close to the celiac trunk (n = 4) partly protected against spinal cord ischemia. This is explained by prevention of the steal phenomenon in the excluded part of the aorta. Adding clamps to the subclavian arteries (n = 6) created complete spinal ischemia as the collateral circulation was interrupted. In another group (n = 4) all segmental arteries below T5 were occluded with no reaction in the intrathecal variables. Additional selective clamping of supreme intercostal arteries (n = 4) showed the relative importance of the subclavian and vertebral collateral pathways.

CONCLUSIONS

Continuous intrathecal PO (2) was monitored during various modes of interruption of the spinal cord blood supply. This provided insight into the ischemia mechanisms and relative importance of the segmental contribution and proximal collateral pathways of the spinal cord circulation in pigs. A short literature review is given, and aspects of comparative anatomy are discussed.

One-stage approach for retroperitoneal and mediastinal metastatic testicular tumor resection

BACKGROUND

Eight percent of nonseminomatous germ cell tumors of the testis are associated with postchemotherapy residual masses in both the retroperitoneum and the posterior mediastinum. We describe a transabdominal transdiaphragmatic approach that allows simultaneous resection of these masses.

METHODS

After standard retroperitoneal lymph node dissection through a midline laparotomy, an incision parallel to the right crus of the diaphragm was made and extended anteriorly through the muscular portion. Excellent exposure of the lower posterior mediastinum was obtained. Masses located higher than vertebra T8 were resected by extending this incision anteriorly and performing a partial sternal division. A complete median sternotomy can be done to allow subcarinal dissection, as well as pulmonary or anterior mediastinal mass resection.

RESULTS

Between 1993 and 1999, 18 patients had simultaneous resection of retroperitoneal and posterior mediastinal masses with this approach. There were no perioperative deaths; 3 patients had minor postoperative complications. After a median follow-up of 3.2 years, the overall 5-year survival rate was 92%, and the 5-year disease-free survival rate was 87%.

CONCLUSIONS

The transdiaphragmatic approach to the posterior mediastinum is less aggressive than the thoracoabdominal approach. It is safe and effective for simultaneous resection of postchemotherapy testicular nonseminomatous germ cell tumors located in the retroperitoneum and posterior mediastinum.