Great Radicular Artery Research Articles

Fast three-dimensional contrast-enhanced magnetic resonance angiography of the canine lumbar spinal cord vascular supply: A feasibility study.

Magnetic resonance angiography (MRA) is the noninvasive spinal cord vascular imaging modality of choice in human medicine. The aim of this exploratory, prospective, descriptive study was to assess the feasibility of fast three-dimensional (3D) contrast-enhanced (CE) MRA for visualization of spinal vascular structures in the canine lumbar region. Fourteen canine patients weighing>5kg were included. The lumbar arteries were consistently visualized (14/14;100%). Spinal arteries, radicular branches, great radicular artery (of Adamkiewicz), ventral spinal artery, and dorsal spinal arteries were not visualized (0/14;0%). The internal vertebral venous plexus was visualized in 11 of 14 (79%) dogs. Overall, the results of this study show that fast 3D CE-MRA of the lumbar region in dogs is feasible. However, the smaller arteries responsible for the spinal cord vascular supply were not visualized in this study.

Acute spinal subarachnoid haematoma following spinal anaesthesia treated conservatively: case report

Acute spinal subarachnoid haematoma following spinal anaesthesia treated conservatively: case report

Acute infra-renal aortic dissection presenting as back pain and transient paralysis of the lower limbs

Spinal cord injury is a rare complication in patients with aortic dissection. Spinal ischaemia has been reported as a complication of aortic dissection due to impairment of its extrinsic supply in the great radicular artery (GRA) of Adamkiewicz. The extrinsic arterial blood supply to the spinal cord, diminishes caudally and is believed to become critically dependent upon the GRA.1 infra-renal aortic dissections (IAAD) inducing spinal ischaemia are exceptionally rare in the literature. We present a case of an infra-renal aortic dissection (IAAD) presenting with transient spinal ischaemia.

Advances in Imaging of the Spinal Cord Vascular Supply and its Relationship with Paraplegia after Aortic Interventions. A Review

Introduction: Preoperative knowledge of the spinal cord (SC) vasculature could be useful for stratifying and decreasing the risk of perioperative paraplegia after thoracic and thoraco-abdominal aortic surgery. Recent advances in magnetic resonance (MR) and computed tomography (CT) angiography and post-processing techniques have improved this knowledge. Methods: A search of MEDLINE/Pubmed and SCOPUS databases identified 1414 pertinent abstracts; 123 full-length manuscripts were screened to identify relevant studies with acceptable design and patient numbers. Forty-three were selected. Results: SC circulation was studied in 1196 patients to detect the great radicular artery: 522 by MR-angiography and 674 by CT angiography. Detection rates were 67–100% (mean 80.8%) with MR-angiography being 18–100% (mean 72%) with CT angiography. The side and level of the great radicular artery were consistent between the methods. Several authors tried to use the imaging results to guide clinical management. Conclusions: Non-invasive imaging of the SC blood supply allows preoperative definition of the vasculature in many, but not all, cases. The impact of these findings on clinical management is potentially beneficial but still uncertain. Further improvements in image acquisition and post-processing techniques are needed. Future studies need to be large enough to compensate for inter-individual variability in SC vasculature in health and disease; however, even a partial reduction of paraplegia rate offers a formidable motivation for further research in this area.

Advances in Imaging of the Spinal Cord Vascular Supply and its Relationship with Paraplegia after Aortic Interventions. A Review

Preoperative knowledge of the spinal cord (SC) vasculature could be useful for stratifying and decreasing the risk of perioperative paraplegia after thoracic and thoraco-abdominal aortic surgery. Recent advances in magnetic resonance (MR) and computed tomography (CT) angiography and post-processing techniques have improved this knowledge. A search of MEDLINE/Pubmed and SCOPUS databases identified 1414 pertinent abstracts; 123 full-length manuscripts were screened to identify relevant studies with acceptable design and patient numbers. Forty-three were selected. SC circulation was studied in 1196 patients to detect the great radicular artery: 522 by MR-angiography and 674 by CT angiography. Detection rates were 67-100% (mean 80.8%) with MR-angiography being 18-100% (mean 72%) with CT angiography. The side and level of the great radicular artery were consistent between the methods. Several authors tried to use the imaging results to guide clinical management. Non-invasive imaging of the SC blood supply allows preoperative definition of the vasculature in many, but not all, cases. The impact of these findings on clinical management is potentially beneficial but still uncertain. Further improvements in image acquisition and post-processing techniques are needed. Future studies need to be large enough to compensate for inter-individual variability in SC vasculature in health and disease; however, even a partial reduction of paraplegia rate offers a formidable motivation for further research in this area.

Paraplegia following the emergency surgical repair of a nonruptured symptomatic abdominal aortic aneurysm: Report of a case

This report presents an extremely rare case of paraplegia following emergency surgery for a nonruptured symptomatic abdominal aortic aneurysm. A 62-year-old man underwent an emergency surgical repair for a symptomatic nonruptured infrarenal abdominal aortic aneurysm. On postoperative day 2 paraplegia following spinal cord ischemia occurred at the T8 level. The site of the ischemia was situated too high for clamping to have caused this condition, unless the patient had a congenital anomaly in the blood supply to the spinal cord or it had been caused by the previously occluded great radicular artery, which was maintained by the collateral blood supply from the iliac circulation.

Aortic fenestration for chronic aortic dissection type B complicated by transient ischemic attacks of spinal cord

Spinal cord injury is a rare complication in patients with aortic dissection. The extrinsic arterial supply to the spinal cord, diminishing caudally, often becomes critically dependent on the great radicular artery (GRA) of Adamkiewicz at the thoracolumbar spine. There are no prior reports of spinal injury or ischemia caused by chronic aortic dissection. We report on a 51-year-old patient with chronic type B dissection of the aorta from below the subclavian takeoff through the iliac arteries, presented with multiple episodes of transient (1 to 5 minutes) spinal ischemic attacks, entailing sudden loss of motor and sensory functions in both legs, with collapse of the patient on the ground. GRA imaging acquired with 64-channel computed tomography angiography enabled aortic fenestration from T11 to L1, performed with supraceliac aortic cross-clamping (T8 to L2) via thoracoabdominal access. We critically appraise the pertinent literature.

Pro: It Is Safe to Proceed With Thoracoabdominal Aortic Aneurysm Surgery After Encountering a Bloody Tap During Cerebrospinal Fluid Catheter Placement

URING THE PAST 20 years, major advances in the intraoperative management of patients undergoing thoracoabdominal aortic aneurysm (TAAA) surgery have substantially reduced postoperative primary morbidity and mortality. At present, mortality rates after TAAA repair are estimated to be 5% to 10%, neurologic deficits 3% to 10%, renal failure 8% to 29%, and pulmonary complications 30% to 40%.1-4 Among the most feared complications of thoracic aortic aneurysm (TAA) and TAAA surgery are paraparesis and paraplegia, which are estimated to occur in 6% to 10% of patients who undergo TAA or TAAA repair. 5,6 Patients with these complications have a 20% greater risk of mortality than do patients without postoperative paraparesis or paraplegia. These patients, who are usually older, require intensive rehabilitation. A patient’s risk of postoperative paraparesis and paraplegia is determined by aneurysmal extent, acute dissection, cross-clamp time, preoperative renal dysfunction, previous aortic surgery, diabetes, and rupture.7 Improvements in TAAA repair procedures, including reduced cross-clamp time, distal aortic perfusion, and reattachment of intercostal arteries, have minimized critical ischemic times. Adjuncts such as cerebrospinal fluid (CSF) drainage, spinal cord monitoring, atrial femoral bypass, regional and systemic cooling, intrathecal papaverine, intraoperative use of naloxone, steroids and barbiturates, and the recognition and treatment of factors related to coagulopathy, have also been introduced. 8 The arterial circulation of the spinal cord consists of 2 interconnected sources: intrinsic and extrinsic. The intrinsic blood supply consists of a single anterior spinal artery (ASA), which courses along the ventral aspect of the cord and ultimately supplies the bulk of the cord substance through penetrating arteries, and paired posterior spinal arteries, which supply the remainder of the cord. This intrinsic circulation in turn receives its extrinsic blood supply via the radiculomedullary arteries, although the anatomic details of this supply vary among individuals. The principal extrinsic blood supply in the cervical and upper thoracic region comes from branches of the vertebral arteries; the thoracolumbar cord is supplied by intercostal and lumbar arteries, and the conus is supplied by the lateral sacral branches of the hypogastric vessels. There are 2 aspects of the spinal cord circulation that explain the risk of cord ischemia during TAAA repair. First, the diameter and continuity of the ASA vary along its length. Angiographic studies have shown that the ASA becomes extremely narrow cephalad to its anastomosis with the great radicular artery. Second, the human spinal cord is irregularly supplied by the radiculomedullary arteries because only few of them actually reach the cord substance. The thoracolumbar region is at the most risk for ischemic injury because this region is typically supplied by a single radiculomedullary artery, better known as the artery of Adamkiewicz or arteria radicularis magna. This artery has been shown to arise from T9 to T12 in about 75% of individuals. Because this area falls within the segment of the aorta that is clamped during reconstruction, clamping can compromise the blood supply to the cord. With proximal descending aortic cross-clamping, adequate spinal cord perfusion requires ASA patency, collateral circulation, and sufficient spinal cord perfusion pressure, defined as the difference between spinal artery pressure and CSF pressure. 9 During hypoxia and hypercarbia, autoregulation of spinal cord blood flow is lost and flow becomes linearly related to perfusion pressure. For this reason, adjuncts that decrease CSF pressure will increase spinal cord perfusion pressure. The rationale for using a CSF drain is based on experimental data showing that (1) CSF pressure increases during aortic clamping and (2) reducing CSF pressure improves spinal perfusion. Drenger et al 10 observed acute increases in CSF pressure immediately after applying the aortic clamp during TAAA repair. These increases were similar in patients with and without distal bypass and have been attributed to a sudden elevation of cerebral blood flow. The authors also observed a second peak

Preoperative selective intercostal angiography in patients undergoing thoracoabdominal aneurysm repair

ObjectiveThis study was designed to test the hypothesis that detection of the location of the major artery supplying the spinal cord, that is, the artery of Adamkiewicz or the great radicular artery (GRA), with angiography would help prevent paraplegia. Knowing which intercostal artery provides this important branch would enable prompt, focused revascularization. MethodThe surgical outcome in 131 patients with Crawford extent 1 and 2 degenerative aneurysms and 69 patients with descending thoracic aortic dissection was correlated with findings on selective intercostal arteriograms. Angiographic maneuvers were done with care, and the procedures were aborted if there was loose or “shaggy” mural thrombus, significant tortuosity, or difficulty entering each dissection channel. No attempts were made to find major contributions proximal to T6. Subarachnoid drains were placed in all patients, and all but five patients underwent distal aortic perfusion with controlled cooling to 32°F. Five patients underwent cold circulatory arrest, enabling replacement of the distal aortic arch. We defined paraplegia simply as the inability to walk at hospital discharge, paraparesis as impaired ambulation, and both as having spinal cord dysfunction (SCD). ResultsA GRA was found in 65 (43%)of the 151 patients studied. Of the 65 patients with the GRA identified, SCD developed in 3 (4.6%) patients. Thirteen of 135 (9.6%) patients in whom the GRA was not identified, either because they were not studied or were studied and the GRA was not found, developed SCD (P = .35) However, when the GRA was identified, SCD occurred only in the group with aortic dissection. None of the 45 patients with degenerative aneurysms with the GRA identified had SCD, compared with 9 of 55 (16%) patients studied but without a GRA found (P = .01). ConclusionThe approach with selective intercostal angiography did not improve overall results. One third of our patients were not studied, and they fared as well as patients who were studied and the GRA was localized (not studied, 4 of 49, 8% with SCD; GRA localized, 3 of 65, 5% with SCD; P = .8). However, when the GRA was found, SCD occurred only in patients with aortic dissection. The studies confirmed the concept that the existence of mural thrombus in degenerative aneurysms results in the occlusion of many intercostal arteries, leaving those remaining patent to supply rich vascular watersheds through acquired collateral channels. As a result, in the group of patients with degenerative aneurysms, the identification of the critical intercostal artery allows focused reimplantation with uniform success. This is not the case in patients with aortic dissection. In those patients, most intercostal vessels remain patent, such that the insertion of one pair is insufficient to supply the paravertebral plexus and the spinal cord. Finally, failure to identify the GRA angiographically with our methods does not provide assurance that the GRA does not exist. Therefore negative findings did not provide license to ligate all intercostal arteries.

Invited Commentary

The preceding article represents an important contribution because it calls attention to a rare, often complex, life-threatening injury and also provides a discussion of the merits of conventional surgery versus endovascular treatment. With respect to use of endovascular techniques, larger Wallstents, capable of 24- to 25-mm expansion, and bifurcated aortic endovascular stent grafts have, for the most part, resolved difficulties associated with stenting the entire area of dissection. Although small intimal tears can sometimes be managed successfully by observation alone, such patients require prolonged, close follow-up with periodic, contrast-enhanced, spiral CT scans and/or angiography. Contrary to the authors' statements, I believe that fenestration and dilation of the dissection septum between the true and false lumens, with or without stenting, is a safe and effective means for treating branch vessel occlusions, secondary to external compression of the true lumen by the dissection. The etiology of paraplegia after infrarenal aortic dissection is multifactorial, but the major cause is an alteration in the blood supply to the spinal cord, primarily via the great radicular artery (GRA). Even though studies have yielded different results, there is a consensus that the GRA arises between T-5 and L-4, most frequently between T-9 and L-1 levels.1Carmichael S.W. Gloviczki P. Anatomy of the blood supply to the spinal cord the artery of Adamkiewicz revisited.Perspectives Vasc Surg. 1999; 12: 113-122Crossref Scopus (11) Google Scholar Djindjian and Faure,2Djindjian R, Faure C. Accident médullaires de l'aortographie [French]. J Belg Radiol 1967;50:207-18Google Scholar in an angiographic study, located the GRA between T-9 and T-12 in 75% of cases, T-5 and T-8 in 15%, and L-1 or L-2 in 10%. Blood to the distal cord is also supplied by the pelvic circulation, and paraplegia following infrarenal aortic reconstruction can be caused by embolization and/or thrombosis of the internal iliac arteries. Moreover, prevention of prolonged hypotension is of paramount importance. Finally, I wish to mention two patients in whom paraplegia occurred shortly after infrarenal aortic dissection caused by a steering wheel injury. In each patient, the dissection was complicated by thrombotic occlusion of the infrarenal aorta and iliac arteries as well as an inordinate amount of clotting in both lower extremities. Despite repeated use of Fogarty embolectomy catheters and graft replacement of the aorta and common iliacs, satisfactory flow could not be established below the femoral arteries, and both patients died. The presence of extensive clotting in these patients suggested the possibility of a hypercoagulable state initiated by the injury.3Nunn D.B. Abdominal aortic dissection following non-penetrating abdominal trauma.Am Surgeon. 1973; 39: 177-179PubMed Google Scholar, 4Nunn DB. Discussion of James D. Hardy's paper, “Aortic and other arterial injuries.” Proceedings of the Southern Surgical Association; 1974. Vol 86, p. 154-67 [discussion on p. 166-7]Google Scholar

The impact of spinal angiography on the neurological outcome after surgery on the descending thoracic and thoracoabdominal aorta

Background Neurologic complications remain one of the major concerns in surgery on the descending thoracic and thoracoabdominal aorta. The impact of preoperative spinal angiography on postoperative neurologic outcome was assessed. Methods Between September 1993 and December 1999, 109 patients (mean age, 58.2 years; range, 24 to 77) underwent preoperative spinal angiography: 50 (45.9%) for aneurysm and 59 (54.1%) for chronic dissection. Sixty-one patients (56.0%) underwent replacement of the descending thoracic aorta whereas the thoracoabdominal aorta was replaced in 48 (44.0%) patients. All intercostal or lumbar arteries that had previously been visualized as the origin of the great radicular artery (GRA) were preserved. Results The origin of the GRA was located by spinal angiography in 65 of the 109 patients (59.6%). It was found between level T-5 and L-3 and on the left side in 75.4% (49 of 65) patients. In patients with aneurysms, it was identified less frequently (48%) compared with patients with chronic dissection (69.5%, p = 0.02). The overall operative mortality rate was 5.5% (6 of 109 patients). There were 7 patients (6.4%) with postoperative paraplegia. In 3 of them the origin of the GRA had been reimplanted. Conclusions Even in patients with an identified and subsequently reimplanted GRA, postoperative paraplegia could not always be prevented. Spinal angiography has no impact on the neurologic outcome of thoracic and thoracoabdominal aortic replacement.

Identification of the critical spinal arteries with F wave–polysynaptic response complex monitoring: An experimental study

Purpose: The main cause of paraplegia after surgery for descending thoracic aortic aneurysms and thoracoabdominal aortic aneurysms is spinal cord ischemia caused by ligation of the critical spinal arteries that are associated with the great radicular artery (GRA). In this experimental study, we attempted to identify the critical spinal arteries with F wave–polysynaptic response complex (FPC) monitoring. The FPC, which we are using as a monitor of spinal cord ischemia, is myogenic potentials evoked by the tibial nerve stimulation through the anterior horn cells. Method: In 18 rabbits, infrarenal lumbar arteries were clamped until there was an FPC amplitude reduction (FPCAR) of at least 60%. The rabbits were classified according to the number of arteries clamped to produce the FPCAR (group A, 1 artery; group B, 2 arteries; group C, 3 arteries). Selective angiography of each lumbar artery was performed in all rabbits. Results: An FPCAR was observed in all 18 rabbits. In all nine rabbits in group A, the FPCAR was caused by the clamping of one particular lumbar artery. The GRA was shown by means of selective angiography to originate directly from this lumbar artery. In the nine rabbits in groups B and C, 11 FPCARs were observed. Of these, nine FPCARs in nine rabbits were caused by the clamping of lumbar arteries that included the vessel from which the GRA originated. Conclusion: Temporary clamping of lumbar arteries with FPC monitoring can be used as a means of detecting the critical spinal arteries from which the GRA originates. (J Vasc Surg 2001;34:330-6.)

Anatomy of the Blood Supply to the Spinal Cord: The Artery of Adamkiewicz Revisited

A review of embryology and anatomy of blood supply to spinal cord is presented. The main artery supplying anterior cord is great radicular artery (often referred to by eponym the artery of Adamkiewicz). This artery usually originates from left side of aorta, most frequently between ninth thoracic and first lumbar levels to supply blood to anterior spinal artery However, variations in origin of artery are common. Blood supply to spinal cord can be compromised during descending thoracic or thoracoabdominal aortic reconstructions, performed for aneurysmal disease or for aortic dissection. This may lead to devastating neurological complications, most notably paraplegia. Although etiology of paraplegia is multifactorial, a relatively small artery plays an important role in development of serious neurological complications.

A CASE OF RUPTURED ABDOMINAL AORTIC ANEURYSM ASSOCIATED WITH POSTOPERATIVE PARAPLEGIA

We experienced a case of ruptured abdominal aortic aneurysm associated with paraplegia, a 71-year-old woman developed paraplegia following resection of a ruptured infra-renal aortic aneurysm. The aorta was clamped just below the renal artries. The patient developed multiple organ failure and expired on the 24th day. In this case interruption of the great radicular artery (Adamkiewicz artery) might bring about serious ischemia of the spinal cord. Spinal cord damage is a very rare complication in surgery of unruptured abdominal aortic aneurysms. Because the spinal cord is protected from irreversible ischemia during infra-renal aortic occlusion by the presence of an Adamkiewicz artery which arises above the renal or persistent low thoracic radicular artery and other spinal arteries. We feel that this very rare neurologic complication can best be guarded against by reducing aortic clamping time as short as possible and by avoiding hypotensive episode to keep adequate blood flow of collaterals.

Spinal cord angiography in dorsolumbar vertebral fractures with neurological involvement.

Selective angiography of the intercostal and lumbar arteries was performed to delineate the origin and course of the great radicular artery. In dorsolumbar spinal fractures with neurological disorders, the authors recommend decompression and intervertebral spondylodesis by the anterior-lateral approach. Selective angiography can demonstrate the side and level of origin of the artery of Adamkiewicz. It is important to avoid injury to this vessel, which would cause further ischemia of a spinal cord already damaged by the initial trauma.