Endovascular treatment of symptomatic true-lumen collapse of the downstream aorta after open surgery for acute aortic dissection type A

AIM

The aim of the present study was to evaluate the outcome of endovascular treatment of true-lumen collapse (TLC) of the downstream aorta after open surgery for acute aortic dissection type A (AADA).

METHODS

Retrospective, observational study with follow-up of 16 ± 7.6 months. From April 2010 to January 2012, 89 AADA-patients underwent aortic surgery. Out of these, computed tomography revealed a TLC of the downstream aorta in 13 patients (14.6%). They all received additional thoracic endovascular aortic repair (TEVAR) in consequence of malperfusion syndromes.

RESULTS

In all 13 TLC-patients, dissection after AADA-surgery extended from the aortic arch to the abdominal aorta and malperfusion syndromes occurred. Remodeling of the true-lumen was achieved by TEVAR with complemental stent disposal in abdominal and iliac arteries in all cases. One patient died on the third postoperative day due to intracerebral hemorrhage. Another patient, who presented under severe cardiogenic shock died despite AADA-surgery and TEVAR-treatment. Thirty-day mortality was 15.4% in TLC-patients (N = 2/13). In the follow-up period, 3 patients required additional aortic stents after the emergency TEVAR procedures. After 20 weeks, a third patient died secondary to malperfusion due to false-lumen recanalization. Therefore, late mortality was 23.1%.

CONCLUSION

After proximal aortic repair for AADA, early postoperative computed tomography should be demanded in all patients to exclude a TLC of the descending aorta. Mortality is still substantial in these patients despite instant TEVAR application. Thus, in case of TLC and malperfusion syndrome of the downstream aorta, TEVAR should be performed early to alleviate or even prevent ischemic injury.

Acute aortic dissection type A

Background

Acute aortic dissection type A (AADA) is a life-threatening vascular emergency. Clinical presentation ranges from pain related to the acute event, collapse due to aortic rupture or pericardial tamponade, or manifestations of organ or limb ischaemia. The purpose of this review was to clarify important clinical issues of AADA management, with a focus on diagnostic and therapeutic challenges.

Methods

Based on a MEDLINE search the latest literature on this topic was reviewed. Results from the German Registry for Acute Aortic Dissection Type A (GERAADA) are also described.

Results

Currently, the perioperative mortality rate of AADA is below 20 per cent, the rate of definitive postoperative neurological impairment approaches 12 per cent and the long-term prognosis after surviving the acute phase of the disease is good. Many pathology- and therapy-associated factors influence the outcome of AADA, including prompt diagnosis with computed tomography and better cerebral protection strategies during aortic arch reconstruction. Endovascular technologies are emerging that may lead to less invasive treatment options.

Conclusion

AADA is an emergency that can present with a wide variety of clinical scenarios. Advances in the surgical management of this complex disease are improving outcomes.

Long-term patency of open revascularization for visceral artery pathologies

OBJECTIVE

Aim of the study was to evaluate the long-term patency of bypass grafts used to treat occlusive and aneurysmal disease of the visceral arteries.

METHODS

A retrospective analysis of our vascular surgery database identified 30 patients (11 men, mean age 59 ± 14 years) who underwent 32 operations for visceral artery pathology between January 1995 and December 2009. Acute mesenteric ischemia (aMI) was present in 10, chronic mesenteric ischemia (cMI) in 14 and visceral artery aneurysm (VAn) in 7 cases. The primary endpoint of this study was vessel patency, secondary endpoints were survival and freedom from reintervention.

RESULTS

A total of 46 vessels were revascularized (26 bypass grafts) and additional revascularization procedures (thromboembolectomy, patch plasty, transposition) were performed in 21 cases. In the perioperative period, 6 deaths (5 aMI, 1 cMI) occurred, resulting in a mortality rate of 50 % for aMI and 7 % for cMI. At long-term follow-up (55 months), 22 patients (100 % follow-up) were interviewed and 21 were scheduled for clinical and imaging examinations. Four vessel (3 grafts) occlusions were found in these patients.

CONCLUSION

We were able to show that bypass grafting for a visceral artery pathology, although associated with an increased perioperative mortality, is a successful and durable procedure.

Value and pitfalls of neurophysiological monitoring in thoracic and thoracoabdominal aortic replacement and endovascular repair

BACKGROUND

The aim of our study was to analyze the neurophysiological monitoring method with regard to its potential problems during thoracic and thoracoabdominal aortic open or endovascular repair. Furthermore, preventive strategies to the main pitfalls with this method were developed.

METHODS

Between 11/2000 and 05/2007 in 97 cases open surgery or endovascular stentgraft-implantation was performed on the thoracic or thoracoabdominal aorta. Intraoperatively, neurophysiologic motor- and somatosensory-evoked potentials were monitored.

RESULTS

Our cases were divided into four groups: event-free patients with normal potentials (A, 63 cases), with correlation of modified evoked potentials and neurological outcome (B, 14 cases), false-positive or false-negative results (C, 4 cases), and medication interaction or technical issues (D, 16 cases). We observed a sensitivity of 93 % and a specificity of 96 % for the neurophysiological monitoring.

CONCLUSIONS

Monitoring spinal cord function during surgical and endovascular interventions on the thoracic and thoracoabdominal aorta is necessary. It can be made more effective by precisely analyzing the interference factors of the neurophysiological monitoring method itself. Successful strategies of immediate troubleshooting could be identified.

Efficacy of the non-adenosine analogue A1 adenosine receptor agonist (BR-4935) on cardiovascular function after cardiopulmonary bypass

BACKGROUND

We tested the hypothesis that pharmacological preconditioning with a newly developed, potent non-adenosine analogue A1AdoR agonist (BR-4935) improves biventricular cardiac and endothelial function after cardiopulmonary bypass.

METHODS

Twelve anesthetized dogs underwent cardiopulmonary bypass. Dogs were divided into two groups: group 1 (n = 6) received saline vehicle, group 2 (n = 6) received BR-4935 before cardiopulmonary bypass. Biventricular hemodynamic variables were measured using a combined pressure-volume conductance catheter. Coronary blood flow, ATP content, malondialdehyde and myeloperoxidase levels and vasodilatative responses to acetylcholine and sodium nitroprusside were also determined.

RESULTS

Administration of the A1AdoR agonist led to a significantly better recovery of left and right ventricular systolic function after 60 minutes of reperfusion. Although the vasodilatative response to sodium nitroprusside was similar in both groups, acetylcholine resulted in a significantly greater increase in coronary blood flow in the BR-4935 group. In addition, the ATP content was significantly higher in the same group. Furthermore, malondialdehyde and myeloperoxidase levels significantly decreased in the A1AdoR group.

CONCLUSION

Pharmacological preconditioning with a new, potent non-adenosine analogue A1AdoR agonist improves biventricular function recovery and endothelial function after hypothermic cardiac arrest.

Reevaluation of two techniques of harvesting the skeletonized internal mammary artery

BACKGROUND

Selective skeletonization of the internal mammary artery (IMA) without adjacent vasculo-muscular structures reduces trauma to the chest wall, results in elongated grafts, makes ideal graft positioning possible, and eliminates the need to implant a dissected or hypoplastic graft with direct visual control of the vessel. We compared two techniques of skeletonizing the IMA in a prospective randomized trial.

METHODS

51 IMAs were randomly harvested and divided into two groups according to the technique of skeletonization. In group I (n = 31), IMAs were harvested in a skeletonized fashion with the Harmonic Ultrasonic scalpel, and in group II (n = 20) using scissors and hemostatic clips. We compared arterial wall histology, harvesting time, spasm frequency, and the use of hemostatic clips between the two groups.

RESULTS

There were no significant morphological differences in the arterial wall in the two groups. Use of an ultrasonically-activated scalpel reduced the IMA's harvesting time (p < 0.001), the frequency of spasm (p = 0.01), and the use of hemostatic clips (p < 0.001).

CONCLUSIONS

Ultrasonic harvesting of a skeletonized IMA is a non-traumatic preparatory technique that reduces the costs of surgical clips and that can be performed safely and quickly.

Development of a Special Balloon Occlusion Device to Prevent Adverse Events in High-Risk Patients during Open Aortic Surgery

OBJECTIVE

To prevent clamp injury that may occur during aortic surgery, we aimed to develop a special balloon occlusion (BO) device to lower the thromboembolic risk in patients with severe atherosclerosis during aortic aneurysm repair.

METHODS

The study comprised two test phases: a laboratory-testing series focussing on flexible artificial aortas, and an experimental series conducted on 10 pigs.

RESULTS

The device proved to be effective during the laboratory tests and the experiments on pigs. No complications such as intraoperative balloon rupture, dislocation, or occlusion leaks occurred. No damage to the aortic vessels was observed in further histological examinations.

CONCLUSIONS

This BO device has the potential to become an alternative to cross-clamping for vascular surgeons in patients with severely atherosclerotic vessels.

Actual management of patients with familial ascending aortic aneurysms and type-A aortic dissections

BACKGROUND

There are few families with the diagnosis of ascending aortic aneurysm and acute type-A aortic dissection inherited as an autosomal-dominant disorder in the absence of a known genetic syndrome.

METHODS

We investigated a family with 26 members in whom ascending aortic aneurysms and acute type-A aortic dissections occurred over three generations. Examinations were performed to identify family members at specific risk.

RESULTS

Six members presented with acute type-A aortic dissections and three relatives had ascending aortic aneurysms. Clinical examinations showed no characteristics of a known genetic syndrome. Molecular genetic analysis revealed no mutations known to cause a form of autosomal-dominant inherited aortic disease.

CONCLUSION

Adequate diagnostic measures are mandatory in families with ascending aortic aneurysms or type-A aortic dissections to identify or exclude family members at risk for aortic diseases. Even in the absence of identifiable mutations causing isolated aortic aneurysms or aortic dissections, we recommend standardised examinations of all first-degree relatives of affected families. An indication for prophylactic aortic root replacement should be considered for patients at risk.

Efficacy and Frequency of Cerebrospinal Fluid Drainage in Operative Management of Thoracoabdominal Aortic Aneurysms

BACKGROUND

Paraplegia remains the most dreaded complication following thoracoabdominal aortic repair. We investigated the efficacy of cerebrospinal fluid drainage as a spinal cord-protecting modality. We also evaluated the correlation between the frequency of cerebrospinal fluid drainage and the Crawford classification.

METHODS

Spinal cord function was monitored during 20 open surgical procedures (group I) and 27 stent-graft implantations (group II). Evoked potentials and intracranial pressure were monitored in each operation. If intracranial pressure exceeded 15 mmHg, cerebrospinal fluid was drained.

RESULTS

Cerebrospinal fluid drainage was necessary in 75 % of patients in group I (Crawford type I: 33 %, type II: 40 %, type III: 20 %, type IV: 7 %) and in 22 % of patients in group II (Crawford type I: 33 %, type II: 66 %). Evoked potential alterations correlated with an increase in intracranial pressure. Timely cerebrospinal fluid drainage reversed these changes in 72 %. Three patients remained paraplegic.

CONCLUSION

Cerebrospinal fluid drainage is a valuable neuroprotective interventional tool to lower the risk of spinal cord ischemia. The combination of neurophysiological monitoring and cerebrospinal fluid drainage optimizes the prevention of paraplegia during aortic repair.