Thoracoabdominal aortic surgery with special reference to spinal cord protection and perfusion techniques. "Second Nordic Workshop-group"

Spinal cord protection in thoracoabdominal aortic aneurysm surgery: a multimodal approach

Spinal cord injury (SCI) is one major complication of open and endovascular thoracic and thoracoabdominal aortic aneurysm repair. Despite numerous neuroprotective adjuncts, the incidence of SCI remains high. This review article discusses established and novel adjuncts for spinal cord protection, including priming and preconditioning of the paraspinal collateral network, intraoperative systemic hypothermia, distal aortic perfusion, motor- and somatosensory evoked potentials and noninvasive cnNIRS monitoring as well as peri- and postoperative drainage of cerebrospinal fluid. Regardless of the positive influence of many of these strategies on neurologic outcome, to date no strategy assures definitive preservation of spinal cord integrity during and after aortic aneurysm repair.

Distal aortic perfusion during thoracoabdominal aneurysm repair for prevention of paraplegia

BACKGROUND

During thoracoabdominal aortic aneurysm (TAAA) surgery, decreased spinal cord perfusion can result in neurological deficits such as paraplegia and paraparesis. Distal aortic perfusion, alone or in combination with other adjuncts, may counter the decrease in spinal cord perfusion and hence reduce the risk of spinal cord injury.

OBJECTIVES

To determine the effectiveness of distal aortic perfusion with or without other adjuncts against other adjuncts without use of distal perfusion during TAAA surgery in reducing the risk of developing paraplegia and paraparesis.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Specialised Register (last searched 5 January 2012) and CENTRAL (Issue 4, 2011) were searched for publications describing randomised controlled trials of distal aortic perfusion during thoracoabdominal aortic aneurysm surgery. Reference lists of relevant studies were checked.

SELECTION CRITERIA

Randomised or quasi-randomised controlled clinical trials of distal aortic perfusion during TAAA repair.

DATA COLLECTION AND ANALYSIS

Studies identified for potential inclusion were independently assessed for inclusion by at least two authors, with excluded trials arbitrated by the third author.

MAIN RESULTS

There were no randomised controlled trials identified.

AUTHORS' CONCLUSIONS

Currently, there are no randomised controlled trials to support the role of distal aortic perfusion in TAAA surgery for prevention of neurological injury. However, randomised controlled trials are not always feasible based on ethical grounds. Observational studies suggest that distal aortic perfusion alone or in combination with other adjuncts, that is cerebrospinal fluid (CSF) drainage, reduces the rate of neurologic deficit across all types of TAAA; in particular making a striking difference in the rate of neurologic deficit following type II TAAA repair. In the absence of randomised controlled trials, we recommend a standardised approach to reporting through registry studies to strengthen the evidence base for distal aortic perfusion.

Mid-term Survival and Costs of Treatment of Patients with Descending Thoracic Aortic Aneurysms; Endovascular vs. Open Repair: a Case-control Study

OBJECTIVES

To evaluate the results of open surgery or endovascular stent graft repair of descending thoracic aortic aneurysm (TAA).

DESIGN, MATERIALS AND METHODS

This is a retrospective multicenter study of 95 patients undergoing TAA repair (42 stent grafts, 53 open repair). The median age was 67 years. Post-operative complications, mid-term survival and costs were assessed. The results were pooled with data in the literature.

RESULTS

After a mean follow up of 26 months (open group) and 15 months (endovascular group) survival was similar for patients treated by either repair method. Post-operative pneumonia was more in the open group (p <0.02). The hospital costs of open treatment were 40% more than that of the endovascular procedure. Combining the present results with pooled data from the literature the peri-operative mortality and paraplegia rate was less in the endovascular group (p <0.05).

CONCLUSIONS

These retrospective data suggest that endografting of descending thoracic aneurysms can be performed with less peri-operative morbidity, at lower hospital costs, but with equal mid-term life expectancy, compared with open grafting.

Shunting of the Coeliac and Superior Mesenteric Arteries during Thoracoabdominal Aneurysm Repair

OBJECTIVES

To describe our experience with shunting of the coeliac and superior mesenteric arteries during thoracoabdominal aneurysm repair.

DESIGN

Retrospective study.

MATERIAL

Eight patients undergoing resection and graft replacement of Crawford type III (5) and type IV (3) thoracoabdominal aortic aneurysms were included in this series. One patient had rupture, four were symptomatic and three were operated on electively.

METHODS

A vascular graft with a sidearm was applied for the reconstructions. A T-shunt was connected to the sidearm. Following completion of the proximal anastomosis the shunt was inserted into the coeliac and superior mesenteric arteries. The anastomoses to these arteries and the renal arteries were then completed. Finally the distal anastomosis was performed.

RESULTS

There was no early mortality (30 days). One patient had postoperative paraparesis, but recovered quite well. Reoperation became necessary due to sigmoid necrosis in one patient and due to haemorrhage in another. During the follow-up period four patients died but the other patients are alive between 3 and 8 years after surgery.

CONCLUSION

The application of shunting of the superior mesenteric and coeliac arteries during thoracoabdominal aortic surgery is feasible and the results have been acceptable. Further investigation of the optimal blood flow needed to avoid intestinal ischaemia in a larger series of patients is desirable.

Complications of lumbar drainage after thoracoabdominal aortic aneurysm repair

OBJECTIVES

Paraplegia remains a frequent complication of thoracoabdominal aortic aneurysm (TAAA) repair. Many adjunct therapies have been developed to address this complication. Lumbar drainage is frequently used in an attempt to decrease intrathecal pressure and improve intramedullary perfusion pressure. The effectiveness of this therapy is unclear, and the complications of lumbar drainage used for this indication are unknown. We present a case of intraspinal hematoma with significant neurologic deficit after TAAA repair and review the associated complications of lumbar drains placed for TAAA.

METHODS

The charts of all patients undergoing operations for TAAA repair were reviewed. Patients who underwent perioperative placement of a lumbar drain were included regardless of aneurysm type or etiology. Demographics, Crawford grade, and perioperative parameters and complications were reviewed.

RESULTS

Sixty-five patients underwent TAAA repair with 62 (95%) receiving a preoperative lumbar drain. There were two (3.2%) intraspinal hemorrhagic complications, including one patient with a poor neurologic outcome. No infections or other complications directly related to drainage were identified. Multivariate logistic regression analysis failed to demonstrate a significant association between lumbar drain complications and perioperative and intraoperative parameters such as blood loss or hypotension, level of drain placement, and Crawford grade.

CONCLUSIONS

Lumbar drainage is a frequent adjunct to TAAA repair. However, placement of the drain itself can be associated with significant complications whose aggravating factors may be unidentifiable. Complications resulting from lumbar drainage should be considered in any patient who has postoperative lower extremity neurologic deficits.

Thoracic aortic stent grafts--early experience from two centres using commercially available devices

OBJECTIVES

open surgical intervention for aneurysms of the distal arch and descending thoracic aorta is associated with high morbidity and mortality. Stent grafts offer an attractive alternative treatment for these aneurysms. The aim of this study was to assess the morbidity and mortality of endovascular treatment for these aneurysms with stent grafts.

DESIGN, PATIENTS AND METHODS

a prospective observational study was performed of 37 consecutive patients treated from July 1997 to October 2000 (30 at Guy's and St. Thomas' and 7 at Sheffield). Indications included degenerative aneurysms (n=18), false aneurysm (5), acute dissection (4), aortic transection (4), aneurysm related to previous surgery for coarctation (3), chronic dissection (2) and traumatic dissection (1). Nineteen were performed as elective and 18 as non-elective procedures.

RESULTS

three non-elective patients died in hospital (in-hospital and 30-day mortality 8%) and one suffered a stroke with spontaneous full recovery. No elective patient died. One patient with a persistent proximal endoleak required conversion to open repair at 6 weeks. Two patients with persistent flow into the sac at 24 h spontaneously thrombosed at subsequent 3 month follow-up. Two further patients developed new distal endoleaks at 3 months and required distal extension cuffs. One patient died at 28 months of aortic rupture. Serial CT scans had shown prolapse of the stent graft into the aneurysm sac and the patient died just before planned endovascular repair. No patient suffered paraplegia or renal failure. Intensive care facilities were only required for patients who needed them preoperatively.

CONCLUSIONS

thoracic stent grafts can be performed with low morbidity and mortality. They offer a realistic alternative to open surgery. Long term follow up is required to assess their durability.