Quick, simple clamping technique in descending thoracic aortic aneurysm repair

Incidence of spinal cord ischemia according to the patency of reimplanted segmental arteries during thoracoabdominal aortic replacement

BACKGROUND

This study aimed to investigate the impact of segmental artery reimplantation and its patency on spinal cord ischemia (SCI) in thoracoabdominal aorta replacement.

METHODS

For 193 patients who underwent early postoperative computed tomographic (CT) angiography after thoracoabdominal aorta replacement, the technique of segmental artery reimplantation, their patency, and postoperative SCI were retrospectively investigated.

RESULTS

The early patency rate of reimplanted segmental artery was 83.3% (210 of 252), as 13 were taken down intraoperatively and 42 were not visualized in the postoperative CT angiography. The patency rate differed according to the reimplantation technique: 93.6% (131/140) for en bloc patch, 95.6% (43/45) for small individual patch, and 53.7% (36/67) for graft interposition. SCI occurred in 13 (6.3%) patients, 4 of whom (2.0%) remained paraplegic permanently. SCI was significantly more frequent (P=0.044) in the patients in whom segmental artery reimplantation was not successful (take-down or occlusion, 6/37=16.2%) than in those who had all segmental arteries sacrificed intentionally (2/64=3.1%) and those who showed patency of all reimplanted segmental arteries (5/92=5.4%). Especially, there was no permanent paraplegia in the last group. Failure of intended segmental artery reimplantation was a significant risk factor of postoperative SCI in logistic regression analysis (P=0.012; odds ratio 4.65, 95% confidence interval 1.41-15.36).

CONCLUSIONS

During thoracoabdominal aorta replacement, attention should be paid to the segmental artery reimplantation technique, which affects the risk of occlusion or intraoperative takedown and thereby may have impact on postoperative SCI.

Bypass Techniques for Descending Thoracic Aortic Surgery

The conduct of partial left heart bypass or partial car diopulmonary bypass (CPB) during surgery involving the descending thoracic aorta or thoracoabdominal aorta is one of the most unappreciated and misunder stood extracorporeal circulation procedures in cardio vascular surgery. It is different from conventional CPB, and although some uninitiated practitioners consider it simpler, it is in fact more complicated than conven tional CPB and involves different concepts. It requires expertise and skill in regulating the flow, pressure, and oxygenation of blood going to both the proximal and distal parts of the body and management of the special bypass or shunt procedures used, specialized monitor ing, and knowledge about the protection and preserva tion of organs both proximal and distal to the aortic clamping. It demands exquisite communication and un derstanding of the unique problems faced by the sur geon, anesthesiologist, and perfusionist.

Endovascular Repair For Thoracic Aortic Disease: Tertiary Single-center Experience In Northwestern Greece

The purpose of this article is to report the initial experience with endovascular repair of thoracic aortic disease in a single tertiary vascular unit in northwestern Greece.

Between 2003 and 2005, 16 patients were treated with endovascular techniques for various pathologies of the descending thoracic aorta. Twelve patients were treated electively and four emergently. Operative and follow-up data for a mean time of 18.4 months were retrospectively collected and analyzed.

Primary technical success was obtained in 14 (87.5%) cases. No early or late deaths occurred, and there was no major operation-related complication. No paraplegia was observed in our patients. Stent graft–related complications occurred in 18.75% (one type 2 and two type 3 endoleaks), but they all had a favorable outcome. No further problems have been reported in any of our patients.

Endovascular stent graft repair for diseases of the thoracic aorta seems to be a promising alternative to open surgery, especially for high-risk patients. Long-term results are needed to confirm the early benefit of this treatment option with regard to morbidity and mortality rates. The potential of this technique to be applicable even in relatively small, tertiary vascular centers might be of great benefit to patients.

Spinal cord injury following thoracic and thoracoabdominal aortic repairs

Objective

To discuss the currently available approaches to prevent spinal cord injury during thoracic and thoracoabdominal aortic repairs.

Methods

We carried out a PubMed search up to 2013 using the Medical Subject Headings: “aortic aneurysm/surgery” and “spinal cord ischemia”; “aortic aneurysm, thoracic/surgery” and “spinal cord ischemia”; “aneurysm/surgery” and “spinal cord ischemia/cerebrospinal fluid”; “aortic aneurysm/surgery” and “paraplegia”. All 190 original articles satisfying our inclusion criteria were analyzed for incidence, predictors, and other pertinent variables related to spinal cord injury, and we compared the results in recent publications with those in earlier reports.

Results

The mean age of the 38,491 patients was 65.3 ± 4.9 years. The overall incidence of paraplegia and/or paraparesis was 7.1% ± 6.1% (range 0%–32%). The incidence of spinal cord injury before 2000, from 2001 to 2007, and 2008–2013 was 9.0% ± 6.7%, 7.0% ± 6.1%, and 5.9% ± 5.2%, respectively ( p = 0.019). Various predictors of spinal cord injury were identified, extent of disease being the most common. Modification of surgical techniques, use of adjuncts, and better understanding of spinal cord perfusion physiology were attributed to the decrease in postoperative spinal cord injury in recent years.

Conclusions

Spinal cord injury after thoracic and thoracoabdominal aortic repair poses a real challenge to cardiovascular surgeons. However, with evolving surgical strategies, identification of predictors, and use of various adjuncts over the years, the incidence of spinal cord injury after thoracic/thoracoabdominal aortic repair has declined. Embracing a multimodality approach offers a good insight into combating this grave complication.

Staged Hybrid Repair of Thoracoabdominal Aortic Aneurysm after Chronic Type B Aortic Dissection

The purpose of this study was to evaluate clinical outcomes of combined endovascular and open techniques to eradicate false lumen dilatation in the visceral aortic segment after type B aortic dissection associated with aortic aneurysm. We reviewed eight patients with distal thoracic and abdominal false lumen dilatation treated with a staged procedure. These included arch debranching as needed, proximal thoracic endovascular repair, and open surgical correction with abdominal aortic replacement of the visceral and infrarenal aorta. False lumen eradication was successful in all patients. There were no operative deaths, and paraplegia or paraparesis occurred in two patients. During a mean follow-up of 30 months, no complications or secondary interventions were necessary. The thoracic false lumen remained thrombosed in all patients, with no evidence of aortic dilatation or stent graft complications. Complete thrombosis and eradication of the false lumen can be achieved through a three-stage repair of chronic type B aortic dissection with aneurysmal dilatation. A prospective randomized trial is needed to establish the viability of this approach versus standard open repair of type II thoracoabdominal aortic aneurysms.

Surgical resection and survival of patients with unsuspected single node positive lung cancer (NSCLC) invading the descending aorta

BACKGROUND

Surgical treatment of non-small cell lung cancer (NSCLC) with aortic invasion is still debated.

METHODS

Thirteen patients with locally advanced (T4) NSCLC and invasion of the descending aorta underwent pneumonectomy (n=9) or lobectomy (n=4) together with aorta en bloc resection and reconstruction (n=8) or subadventitial dissection (n=5), complete lymph node dissection, and had microscopic unsuspected node metastasis at N1 (n=5) and N2/3 (n=8) levels of whom 12 received radiation therapy. Clamp-and-sew was used to resect and reconstruct the aorta.

RESULTS

Operative mortality and morbidity rate was 0% and 23%, respectively. Four patients died of systemic tumor relapse and 2 of local recurrence. Six patients were alive after a median follow-up of 40 months (range 15-125 months). Overall 5-year survival rate was 45%. Median survival time and 5-year survival rate of patients after aortic resection was 35 months and 67%, respectively, and was 17 months and 0%, respectively, after aortic subadventi-tial dissection (p=0.001). N1 and N2 nodal status adversely affected survival, but survival difference was not significant (N1 versus N2/3; 52% versus 39% at 5 years; p=0.998).

CONCLUSIONS

Aortic resection with single station node positive T4 lung cancer can achieve long-term survival. The data indicate that aortic resection-reconstruction is associated with better outcome than subadventitial dissection.

Penetrating ulcers of the thoracic aorta: results from a single-centre experience

OBJECTIVES

To report our mid-term results of stent-graft (SG) placement for the treatment of penetrating thoracic aortic ulcers.

METHODS

In the last 30 months, 11 patients (9 men; mean age 73 years; range 55 to 81) were treated for 12 penetrating thoracic aortic ulcers using SGs. Five patients were symptomatic: 2 had ruptured ulcers and 2 cases were complicated with dissection. Mean European System for Cardiac Operative Risk Evaluation (EuroSCORE) was 10. Three patients had concomitant endovascular repair for an infrarenal abdominal aortic aneurysm (AAA). Follow-up included periodic computed tomography angiography (CT-A) scans at 1, 4, and 12 months after the intervention, and yearly thereafter.

RESULTS

Primary technical success was achieved in 100% of patients; no conversion was required. In-hospital mortality did not occur. Paraplegia was not observed. Mean follow-up was 15 months (range 2 to 36). One patient died of respiratory failure 2 months after the intervention. Radiologic follow-up did not detect endoleaks. Survival was 90% at 1 and 3 years.

CONCLUSIONS

Our experience confirms the feasibility of SG treatment for elective and urgent repair of penetrating aortic ulcers. Our current attitude is to treat all the ulcers of the descending aorta using an endovascular technique, since SG treatment represents a good treatment option, as the morbidity and mortality are low.

Magnetic resonance angiography and neuromonitoring to assess spinal cord blood supply in thoracic and thoracoabdominal aortic aneurysm surgery

OBJECTIVE

Preoperative knowledge of the blood-supplying trajectory to the spinal cord is of interest, because spinal cord ischemia may occur during thoracic aortic aneurysm (TAA) and thoracoabdominal aortic aneurysm (TAAA) repair and possibly leads to paraplegia. The Adamkiewicz artery (AKA) is considered to be the most important blood supplier of the thoracolumbar spinal cord and has therefore been the focus in preoperative diagnostic imaging. However, in TAA(A) patients, the blood supply to the spinal cord may strongly depend on (intersegmental) collateral circulation, because many segmental arteries are occluded as a result of atherosclerosis. Therefore, the importance of preserving the segmental artery supplying the AKA (SA-AKA) is debated. Here it was investigated whether (1) the AKA and its segmental supplier can be imaged by using magnetic resonance (MR) angiography and (2) aortic cross-clamping of the SA-AKA influences intraoperative spinal cord function, monitored by motor evoked potentials (MEPs).

METHODS

Preoperative MR angiography was performed to localize the SA-AKA and the AKA in 60 patients (19 TAA, 7 TAAA I, 18 TAAA II, 9 TAAA III, and 7 TAAA IV). Spinal cord function was monitored during surgery by using MEPs. When MEPs indicated critical ischemia, the SA-AKA was selectively reattached. To test whether aortic cross-clamping of the SA-AKA was associated with MEP decline, the Fisher statistical exactness test was applied.

RESULTS

The AKA and SA-AKA could be localized in all 60 (100%) patients between vertebral levels T8 and L2 (72% left sided). In 44 (73%) patients, the SA-AKA was cross-clamped, which led in 32% (14/44) of cases to MEP decline. Reattachment of the preoperatively localized SA-AKA re-established MEPs and, thus, spinal cord function in 12 of 14 cases. When the SA-AKA was outside the area cross-clamped, the MEPs always remained stable. A significant association (P < .01) was found between the location of the SA-AKA relative to the aortic cross-clamps and the MEPs.

CONCLUSIONS

The AKA can be localized before surgery in 100% of TAA(A) patients by using MR angiography. Location of the SA-AKA outside the cross-clamped aortic area is attended with stable MEPs. Interestingly, it was found that in most patients in whom the SA-AKA was cross-clamped, MEPs were not affected, thus indicating sufficient collateral blood supply to maintain spinal cord integrity. Nevertheless, preoperative knowledge of SA-AKA location is of importance, because in 32% of patients, spinal cord function was dependent on this supplier. Revascularization of the SA-AKA can thereby reverse spinal cord dysfunction.

Administration of Octreotide for Management of Postoperative High-Flow Chylothorax

Chylothorax is a rare complication of adult cardiothoracic surgery that can affect the postoperative course as it can lead to respiratory insufficiency, protein loss, fluid imbalance, and immunodeficiency. We report the case of a 51-year-old man who developed a persistent high-flow chylothorax after replacement of the descending thoracic aorta for an aneurysm. After a week of complete oral intake cessation and total parenteral nutrition, we started administration of octreotide, a somatostatin analog. It led to rapid cessation of chyle production, and the patient was discharged without further complications and chylothorax relapses.

Complications after endovascular stent-grafting of thoracic aortic diseases

Background

To update our experience with thoracic aortic stent-graft treatment over a 5-year period, with special consideration for the occurrence and management of complications.

Methods

From December 2000 to June 2006, 52 patients with thoracic aortic pathologies underwent endovascular repair; there were 43 males (83%) and 9 females, mean age 63 ± 19 years (range 17–87). Fourteen patients (27%) were treated for degenerative thoracic aortic aneurysm, 12 patients (24%) for penetrating aortic ulcer, 8 patients (15%) for blunt traumatic injury, 7 patients (13%) for acute type B dissection, 6 patients (11%) for a type B dissecting aneurysm; 5 patients (10%) with thoraco-abdominal aortic aneurysms were excluded from the analyses. Fifteen patients (32%) underwent emergency treatment. Overall, mean EuroSCORE was 9 ± 3 (median 15, range 3–19). All procedures were performed in the theatre under general anesthesia. All complications occurring during hospitalisation were recorded. Follow-up protocol featured CT-A, and chest X-rays 1, 4 and 12 months after intervention, and annually thereafter.

Results

Primary technical success was achieved in all patients; procedures never aborted because of access difficulty. Conversion to standard open repair was never required. Mean duration of the procedure was 119 ± 75 minutes (median 90, range 45–285). Mean blood loss was 254 mL (range 50–1200 mL). The mean length of the aorta covered by the SGs was 192 ± 21 mm (range 100–360). The LSA was over-stented in 17 cases (17/47, 36%). Overall 30-day operative mortality was 6.4% (3/47). Major complications included pneumonia (n = 9), cerebrovascular accidents (n = 4), arrhythmia (n = 4), acute renal failure (n = 3), and colic ischemia (n = 1). Overall, endoleak rate was 14%.

Conclusion

Although this report is a retrospective and not comparative analysis of thoracic aortic repair, the combined minor and major morbidity rate was lower than previous reported to results of either electively and emergency performed conventional repair.

Emergency endovascular stent-graft treatment for acute thoracic aortic syndromes

OBJECTIVE

We report the results of our ongoing experience of urgent and emergency stent-graft implantation in acute thoracic aortic syndromes.

METHODS AND RESULTS

In the last 5-years, 19 patients were treated for acute thoracic aortic syndromes. Traumatic rupture was diagnosed in 7 patients, complicated acute type B dissection was present in 5 patients, penetrating ulcer in 4, and symptomatic thoracic aortic aneurysm in 3 patients. There were 17 male patients with a mean age of 54 +/-26 years (range 18-87 ; median 63). Patients were treated in the theatre suite under general anesthesia. Stent-graft placement was technically successful in all patients. The early postoperative mortality was 10.5 %. Neurological events or upper arm ischemia due to overstenting of the left subclavian artery were not observed. Average intensive care unit and hospital stay were 18 and 21 days, respectively. Major complications occurred in 6 patients. Follow-up ranged between 3 and 60 months (mean 25) and included clinical examinations and serial CT-angiography at 1, 4 and 12 months, and every year thereafter. Only one type II endoleak was detected and treated by coil embolization of the left subclavian artery.

CONCLUSIONS

Our experience suggests emergency stent-graft repair in patients with acute thoracic aortic syndromes is a less-invasive attractive alternative, showing encouraging early and mid-term results.

Intentional coverage of the left subclavian artery during endovascular stent graft repair for thoracic aortic disease

BACKGROUND

Surgical revascularization of the left subclavian artery (LSA) has been performed to warrant arm perfusion and to prevent paraplegia during thoracic stent graft (SG) procedures. We retrospectively investigated the outcome after intentional occlusion of the left subclavian artery during SG repair for thoracic aortic diseases.

METHODS

From December 2000 to June 2005, 11 patients (mean age, 57 +/- 19 years) with a short (<1 cm) proximal aspect of a thoracic aortic lesion underwent intentional LSA coverage to expand the proximal landing zone for SG fixation. Three patients were treated in the emergency setting. We did not perform a prophylactic revascularization of the LSA prior to SG implantation. A preliminary balloon occlusion test of the LSA was not performed in this series. The SG was positioned so that its covering was immediately distal to the left common carotid artery.

RESULTS

SG implantation was technically successful in all patients. Intraoperative mortality was not observed; no patient suffered any impairment of left carotid artery flow. Aortography after SG implantation showed no direct flow in the LSA and refilling of the LSA via the ipsilateral vertebral artery. After the intervention, mean systolic pressure in the left arm decreased by 38 +/- 17 mmHg. The stented length of the aorta was 171 +/- 73 (median, 150). During hospitalization, no patient showed any signs of left arm malperfusion. Paraplegia was not observed. One patient developed transient ischemic attack. During a mean follow-up of 19 +/- 8 months (range, 3-36), all patients were completely asymptomatic and had no functional deficit or temperature differential between arms. No leakage was detected.

CONCLUSION

Intentional LSA occlusion seems to be well tolerated. Prophylactic surgical maneuvers may be relegated to an elective measure after an endovascular aortic intervention when intolerable signs or symptoms of ischemia occur.

The Quick simple clamping technique for the repair of descending aortic aneurysm

The surgical treatment for thoracic and thoraco-abdominal aortic aneurysms still remains a challenge for the surgeon, as it can be complicated by paraplegia. Several techniques were developed in order to decrease the risk of paraplegia. We describe a surgical variation of the 'clamp and sew' technique, named 'Quick simple clamping' technique, that we adopted starting in 1995. In our experience, it has allowed us to eliminate paraplegia. This technique was developed on the basis of anatomical, patho-physiological and fluid-dynamic studies which demonstrated that the anterior spinal artery (ASA) is not interrupted, the arteria radicularis magna is not a terminal artery and the sacrifice of intercostal arteries does not lead to an increasing risk of spinal cord ischemia.

Endovascular repair of lesions involving the descending thoracic aorta

BACKGROUND

Vascular lesions involving the thoracic aorta are often life-threatening conditions that carry significant morbidity and mortality with traditional open surgical repair. Preliminary results suggest that endovascular therapy is an effective and possibly advantageous treatment for diseases of the descending thoracic aorta.

METHODS

Between October 2000 and May 2004, 50 consecutive patients underwent endovascular stent-grafting of lesions involving the descending thoracic aorta. Attempted stent-graft deployment was performed electively in 39 patients and emergently in 11. The pathology of electively treated aortic lesions included degenerative/atherosclerotic aneurysms (n = 24), pseudoaneurysms (n = 11), aortic dissections (n = 2), and penetrating ulcers (n = 2). Emergently treated aortic lesions were for acute rupture due to infectious (mycotic) aneurysms (n = 4), atherosclerotic/degenerative aneurysms (n = 3), acute type B dissections (n = 2), and acute transections (n = 2). Devices used include Talent (n = 45), AneuRx aortic cuffs (n = 2), custom-fabricated Gianturco-Dacron grafts (n = 2), and a modified Cook-Zenith abdominal aortic graft (n = 1). Follow-up was performed at 1-month, 6-months, 1-year, and annually thereafter.

RESULTS

Primary technical success, defined as successful deployment and exclusion of the lesion without evidence of type I or type III endoleak, was achieved in 48 (96%) of 50 patients. In one patient, the procedure was terminated due to inability to access the iliac vessels. In another patient, a type III endoleak was observed at the completion of the primary procedure that required deployment of an additional stent-graft component 2 months later. Of the 49 patients who received endografts, seven underwent secondary procedures to correct endoleaks, with five of these seven requiring the deployment of additional endovascular stent-graft components. Major complications included four in-hospital deaths, with three of these occurring in patients treated emergently. Additionally, respiratory failure (n = 6), multisystem organ failure (n = 2), cerebrovascular accident (n = 2), retroperitoneal hematoma (n = 2), acute renal insufficiency (n = 1), and pulmonary embolus (n = 1) were also observed. The overall endoleak rate was 20%, with five primary (< or = 30 days) and five secondary (> 30 days) endoleaks observed. Five of the endoleaks were treated with the deployment of one or more additional endovascular stent-graft components. Two of the endoleaks were treated with endovascular balloon remolding. Mean follow-up was 271 days. There were no aneurysm ruptures or aneurysm-related deaths.

CONCLUSIONS

Endovascular treatment of vascular lesions involving the descending thoracic aorta can be safely performed with low morbidity in high-risk patients. Endovascular repair may become an attractive alternative for the treatment of a wide range of pathology along this vascular territory.

The Bicircuit System: Innovative Perfusional Options for Surgical Treatment of the Thoracic Aorta

PURPOSE

Surgical treatment of the thoracic aorta may become challenging when a rapid switch from left heart bypass (LHB) to cardiopulmonary bypass (CPB) is required.

DESCRIPTION

We designed a BICIRCUIT system using a centrifugal pump, a heparinized CPB circuit with a hollow fiber oxygenator, two 3/8 x 3/8 x 3/8 connectors (one placed at the bell inlet draining blood from the left atrium or the venous reservoir and the second placed at the bell outlet directing blood to the oxygenator or femoral artery). Our priming volume was 1100 mL; when switching from LHB to CPB, no additional priming volume was required. The inlet cannula was inserted in the left atrium (for LHB) or femoral vein (for CPB); the outlet cannula was placed in the femoral artery.

EVALUATION

We used the BICIRCUIT in 18 patients: 7 patients with a thoracoabdominal aneurysm, 7 patients with a traumatic rupture of isthmic aorta, and 4 patients with a Stanford type B aortic dissection. Conversion to CPB was required in 3 patients because of hemodynamic deterioration and in 1 patient because of hypothermic circulatory arrest. As we observed progressive worsening of blood gases in another patient during LHB, we also used the blood oxygenator without changing the position of the cannulas. No system failures were observed. Postoperative spinal disturbances did not develop in any patients. All patients were successfully discharged.

CONCLUSIONS

Our BICIRCUIT system offers three different options: LHB, LHB along with blood oxygenation, and CPB. Each option can be safely achieved and adds to the armamentarium of surgeons and perfusionists in caring for patients with pathology of the thoracic aorta.

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.

Magnetic resonance angiographic localization of the artery of Adamkiewicz for spinal cord blood supply

BACKGROUND

The purpose of this study was to determine whether the artery of Adamkiewicz (ARM) can be detected by magnetic resonance angiography and to determine the usefulness of preoperative magnetic resonance angiography evaluation of the ARM.

METHODS

Between April 2000 and December 2003, 120 patients underwent magnetic resonance angiography for detection of the ARM. The morphology of the anterior spinal artery at the ARM junction, as revealed by magnetic resonance angiography, in 99 patients in whom ARM was preoperatively detected was classified into the following three types: noncontinuation of the anterior spinal artery above the ARM junction (type A), continuation of the anterior spinal artery above and below the ARM junction (type B), and noncontinuation of the anterior spinal artery below the ARM junction (type C).

RESULTS

The ARMs were detected in 99 (83%) of 120 patients, and from a total of 110 ARMs 105 (95%) originated from intercostal arteries branching from the left side and 94 (86%) originated between Th9 and Th11. Two ARMs were found in 11 (11%) of 99 patients in whom ARMs were detected. In 107 patients, who underwent magnetic resonance angiography to reveal the morphology of the anterior spinal artery at the ARM junction, the patterns of the anterior spinal artery were type A in 59 patients (55%), type B in 21 patients (20%), type C in 3 patients (3%) and not classified in 24 patients (22%). No spinal cord injury occurred in patients in whom the ARM had been preoperatively detected.

CONCLUSIONS

Preoperative detection of the ARM is possible by magnetic resonance angiography and is very useful for reducing the incidence of ischemic injury of the spinal cord.

Open aortic surgical repair for left hemi-arch stent-graft failure

A surgical technique of endovascular graft explant through an open aortic approach for left hemi-arch stent-graft failure is described. Between January and April 2003, we surgically treated 3 patients previously submitted for stent grafts for isthmic aortic diseases. Two patients had atherosclerotic aneurysm and 1 had a false lumen reperfusion of subacute intramural hematoma. At 6 to 8 months computed tomographic scan follow-ups on all patients showed a rapid enlargement of aortic diameters due to type I endoleaks. The presence of an uncovered proximal stent in the parasubclavian aorta did not allow a simple aortic cross clamping; therefore we performed an open aortic procedure through a left posterolateral thoracotomy, using femoro-femoral bypass and mild hypothermic circulatory arrest. Selective antegrade cerebral perfusion was started within 3 to 5 minutes from aortotomy and graft removal. Left hemi-arch and descending thoracic aortic replacement was then performed with continuous cerebral perfusion. No surgical mortality was observed. Postoperative course was uneventful for neurologic, cardiac, respiratory, and renal complications. The 3-month follow-ups were event free. This approach, associated with rapid stent-graft explant and selective cerebral antegrade perfusion, appears to be a safe and effective surgical strategy for treating this new aortic pathology.

Upper and lower spinal cord blood supply: the continuity of the anterior spinal artery and the relevance of the lumbar arteries

OBJECTIVE

Thoracic and thoracoabdominal aortic repair are still complicated by spinal cord ischemia and paraplegia. The aim of the present article is to present the results of an anatomical study conducted by means of both postmortem injection of the vertebral artery and perfusion of the abdominal aorta.

METHODS

The spinal cord blood supply was investigated in 51 Caucasian cadavers: in 40 cases a methylene blue solution was hand-injected into the vertebral artery, whereas in the remaining 11 cases the abdominal aorta was perfused with a methylene blue solution by means of a roller pump. The level and side of the arteria radicularis magna and the continuity of the anterior spinal artery were recorded.

RESULTS

The anterior spinal artery was a continuous vessel without interruptions along the spinal cord in all 51 cases. The arteria radicularis magna level was variable, ranging from T9 to L5. The arteria radicularis magna arose from a lumbar artery in 36 cases (70.5%) and it was left-sided in 32 cases (62.7%).

CONCLUSIONS

The anterior spinal artery constitutes an uninterrupted pathway between the vertebral arteries, the arteria radicularis magna, and the posterior intercostal and lumbar arteries. Moreover, the arteria radicularis magna arises from a lumbar artery in most of cases. Therefore, the sacrifice of the intercostal arteries during a thoracic aorta repair could be justified, at least from an anatomical standpoint. However, if an extended thoracoabdominal aortic repair is planned, it may be prudent to preserve the blood flow from the lumbar arteries.

Intraoperative monitoring during vascular surgery

The principal objectives of intraoperative monitoring are to improve perioperative outcome, facilitate surgery and reduce adverse events, using continuously collected data of cardiopulmonary,neurologic and metabolic function to guide pharmacologic and physiologic therapy. Although sophisticated and reliable apparatus may be used to collect these data they are useless, or even harmful, without proper interpretation. This article provides a comprehensive overview of recent publications on the history,philosophy, and semantics of monitoring.

Thoracic aortic emergencies: impact of endovascular surgery

BACKGROUND

Conventional surgery for thoracic aortic emergencies, such as contained or free rupture of thoracic aortic aneurysms, acute type B dissections, and traumatic rupture of the thoracic aorta, is frequently associated with a high rate of mortality and morbidity. To obviate this risk, endovascular surgery is considered to be a valid alternative procedure.

METHODS

From March 2001 to July 2002, 15 of 22 patients with acute thoracic aortic syndromes were submitted to endovascular surgery: 3 patients (20%) for traumatic rupture, 4 patients (26.7%) for contained or free rupture of thoracic aortic aneurysm, and 8 patients (53.3%) for acute type B dissection evolving to rupture. Computed tomographic scan was diagnostic in all patients. The stent grafts were introduced through the femoral artery.

RESULTS

In the endovascular group there were no perioperative deaths or open conversions. The intraoperative angiography and computed tomographic scan performed on discharge showed no significant endoleaks and successful sealing of the aortic dissection. Average intensive care unit and hospital stay was 1.7 +/- 0.8 and 5.9 +/- 3.0 days. Follow-up ranged between 4 and 23 months and included clinical examinations and serial computed tomographic scan at 3, 6, and 12 months, and every 6 months thereafter. One 84-year-old patient with thoracic aortic aneurysm died of pneumonia 78 days after endovascular surgery. Only one type 1 endoleak was noted in the first patient with traumatic rupture, 3 months after the procedure.

CONCLUSIONS

Endovascular surgery is a safe technique, showing encouraging early and midterm results and allowing for prompt treatment of associated lesions in complex multitrauma patients.

Circulation of the spinal cord: an important consideration for thoracic surgeons

The spinal cord has significant thoracic arterial watershed areas rendering it vulnerable to intraoperative ischemic damage, clearly mandating a need for postoperative neurologic monitoring. Mechanisms of hypoperfusion include aortic cross-clamping, rib retraction, intercostal artery interruption, and costovertebral junction bleeding. We report cases of primary lung cancer resection, resection of pulmonary metastasis adherent to the thoracic aorta, resection of cartilaginous tumor with chest wall invasion, and esophagomyotomy for achalasia-all complicated by postoperative paraplegia. We review spinal cord circulation, describe mechanisms and patterns of neurologic dysfunction of susceptible watershed areas, and outline roles of preoperative spinal angiography and intraoperative evoked potentials.

Endovascular treatment in diseases of the descending thoracic aorta: 6-year results of a single center

OBJECTIVE

The purpose of this study was to evaluate endovascular treatment in diseases of the descending thoracic aorta.

MATERIAL AND METHODS

This study was designed as a single center's (university hospital) experience. Over a 6-year period (1995 to 2001), thoracic endografts were placed in 74 patients with a diseased descending thoracic aorta who were at high risk for conventional open surgical repair: 34 had atherosclerotic aneurysms, six had posttraumatic aneurysms, 14 had type B dissection with aneurysmal dilatation of the false lumen, 12 had isthmic transections from blunt trauma, five had thoracoabdominal aneurysms (treated with a combined procedure), two had aortic coarctation, and one had an aortobronchial fistula. Twenty-six procedures (35.1%) were conducted as emergencies, and 48 (64.9%) were elective. The feasibility of endovascular treatment and sizing of stent grafts were determined with preoperative spiral computed tomography and intraoperative angiography.

RESULTS

Endovascular operations were completed successfully in all 74 patients; postprocedural conversion to open repair was necessary in three cases. The overall 30-day mortality rate was 9.5% (seven deaths). Temporary neurologic deficits developed in two patients; not one patient had permanent paraplegia. The primary endoleak rate was 20.3% (15 patients). The mean follow-up period was 22 months (range, 3 to 72 months). Five deaths occurred in the follow-up period, and three patients needed secondary conversion to open repair 2, 3, and 14 months after initial endografting.

CONCLUSION

Endoluminal treatment in diseases of the thoracic descending aorta is feasible and may offer results as good as the open method.