[Is local prosthetics of descending thoracic aorta by its distal dissection effective?]

12 patients with distal aortic dissection were included in the study. All had aortic prosthetics and hemodynamic correction. 6 patients (1st group) had hemodynamic correction type I - Cutdown of the false aortic canal and guiding the blood flow to the correct canal. The rest 6 (2nd group) hemodynamic correction type II was performed (guiding blood flow to the both aortic channels). 83,3% of patients of the 1st group demonstrated the false aortic channel thrombosis up to the level of visceral branches, the rest 33,3% of patients had total thrombosis of the false channel. All patients of the 2nd group demonstrated maintenance of the blood flow in both channels, which leaves risk of further aortic dilatation and rupture.

Repeated true lumen collapse after repair of descending thoracic aneurysm in chronic type B dissection

The patient was 69-year-old man. Dilatation of the descending thoracic aorta in chronic type B dissection was revealed on computed tomography. During replacement of the descending thoracic aorta, distal anastomosis was performed in a double-barreled manner. On postoperative day (POD) 3, the patient complained of paralysis and dysesthesia of both legs, and he developed acute renal dysfunction. Based on the results of emergent aortography, we suspected true lumen collapse resulting from an expanded false lumen; therefore, we stabilized the intimal flap to the aortic wall. However, on POD 7 he complained of coldness in both legs. Emergent aortography revealed that occlusion of the abdominal aorta had recurred, and so right axillobifemoral bypass was performed. Preoperative conventional angiography may be mandatory to confirm reentry. There have been several reports of transcatheter fenestration in acute or chronic aortic dissection. The technique would also be effective for postoperative malperfusion.

The role of the renin-angiotensin system in aortic aneurysmal diseases

The renin-angiotensin system has been invoked in the development of both abdominal and thoracic aortic aneurysms. This has been demonstrated experimentally by the chronic subcutaneous infusion of angiotensin II, which consistently leads to development of abdominal aortic aneurysms (AAAs) in mice. Angiotensin II-induced AAAs have highly heterogenous cellular and extracellular matrix characteristics throughout the aorta that change markedly with infusion duration. The mechanistic basis for the reproducible location of AAA development has not been elucidated, but many insights have been provided, especially regarding receptor and inflammatory mechanisms. A recent clinical study provided limited evidence for extrapolating these results to mechanisms of human AAAs. Experimental evidence has also demonstrated that antagonism of angiotensin II type 1 (AT1) receptors prevents ascending aortic aneurysms in a murine model of Marfan's syndrome. A clinical study is currently ongoing to demonstrate the efficacy of AT1 receptor antagonism in humans.

Screening for thoracoabdominal aortic aneurysms in patients with aortoiliac atherosclerosis: a preliminary study

Thoracoabdominal aortic aneurysms (TAAs) usually present with rupture and carry a high morbidity and mortality rate. Early detection of TAAs with screening methods and elective surgical repair could potentially diminish these complications. The present study was aimed at screening for TAA in patients with angiography-proven aortoiliac atherosclerosis (n=43). A group of patients without aortoiliac atherosclerosis was used as controls (n=15). Age, sex and aortic diameter at the level of the T12 vertebra were recorded. The subjects were divided into two age categories, the first made up of those aged less than 65 years and the second those aged 65 years or more. A T12 aortic diameter greater than 35 mm was used to indicate TAA. Statistical analyses were performed by independent t-test and general linear model with age category, sex and atherosclerosis as factors. The mean T12 aortic diameters were greater in patients with atherosclerosis than in the control group (25.2+/-5.0 vs. 22.9+/-2.4 mm; p=0.034). Two out of 43 patients (4.7%) with aortoiliac atherosclerosis had TAA, while no one in the control group had TAA. A general linear model showed that the interaction of age category and sex significantly affected the T12 aortic diameter [F (1.49)=4.044, p=0.050]. Post hoc (LSD) tests revealed that male patients aged over 65 had greater T12 aortic diameters than other patients. We conclude that patients with aortoiliac atherosclerosis may be at greater risk for developing TAA. Ageing and male sex may also be associated with thoracoabdominal aortic enlargement.

The value of motor evoked potentials in reducing paraplegia during thoracoabdominal aneurysm repair

OBJECTIVE

Paraplegia after thoracoabdominal aortic aneurysm (TAAA) repair mainly occurs in patients with Crawford extent I and II. We assessed the impact of monitoring spinal cord integrity and the subsequent adjusted surgical maneuvers on neurologic outcome in repairs of type I and II TAAAs.

METHODS

Surgical repair of TAAAs was performed in 112 consecutive patients with extent type I (n = 42) and type II (n = 70) aneurysms. The surgical protocol included cerebrospinal fluid drainage, moderate hypothermia, and left heart bypass with selective organ perfusion. Spinal cord function was assessed by means of monitoring motor evoked potentials (MEPs). Significant decreased MEPs always generated adjustments, including raising distal aortic and mean arterial pressure, reattachment of visible intercostal arteries, or endarterectomy of the excluded aortic segment with revascularization of back bleeding intercostal arteries.

RESULTS

Motor evoked potential monitoring could be achieved in all patients. By maintaining a mean distal aortic pressure of 60 mm Hg, MEPs were adequate in 82% of patients. Increasing distal aortic pressure restored MEPs in all patients. In 19 patients (17%), MEPs decreased significantly during aortic cross-clamping because of critical spinal cord ischemia. MEPs returned in all patients after spinal cord blood flow was re-established except in three patients with type II TAAA in whom MEPs could not be restored, and absent MEPs at the end of the procedure corresponded with neurologic deficit. Delayed paraplegia developed in two patients owing to hemodynamic instability with insufficient mean arterial blood pressure to maintain adequate spinal cord perfusion.

CONCLUSION

Monitoring MEPs is a highly reliable technique to assess spinal cord ischemia during TAAA repair. A surgical protocol including cerebrospinal fluid drainage, left heart bypass, and monitoring of MEPs can reduce the paraplegia rate significantly. Adjusted hemodynamic and surgical strategies induced by changes in MEPs could restore spinal cord ischemia in most patients, preventing early and late paraplegia in all type I patients. In type II patients, early paraplegia occurred in 4.2% and delayed neurologic deficit in 2.9%. Despite all available measures, complete prevention of paraplegia in type II aneurysms seems to be unrealistic.

[Simulation of stent treatment for aneurysms in the inner bend of aortic arch]

Endovascular stent is a new technique for the treatment of aortic arch aneurysms. The present simulation study of endovascular stent treatment for aneurysms in the inner bend of aortic arch is initiated by the fact that no one has ever investigated the hemodynamics of stented aortic arch aneurysm harboring a bleb. For the comparative convenience, a stented and a nonstented aortic arch aneurysm models were constructed respectively. Physiological blood flows in both models were simulated using the computational fluid dynamics method. The detailed flow patterns, pressure and wall shear stress distributions around the aneurysm of both models were compared and analyzed so as to evaluate the effectiveness of endovascular stent treatment for aortic arch aneurysms. Results showed that the stented model is attributed to substantially different intra-aneurysmal flow patterns versus the nonstented model. Flow activities within the stented aneurysmal sacs are markedly diminished, specifically the pressure and wall shear stress in the bleb were significantly decreased. These phenomena allow us to conclude that endovascular stent can promote intra-aneurysmal thrombus development and attenuating aneurysm rupture risk.

The Use of an Extra-corporeal Graft to Maintain Cerebral Perfusion During Thoracic Endovascular Aneurysm Repair

Endovascular access for aneurysm repair can be challenging in patients with iliofemoral occlusive disease. The carotid artery is an alternative access site, but may increase the risk of cerebral hypoperfusion during stent delivery. We describe a novel approach, where temporary extra-corporeal bypass was used to maintain cerebral perfusion during endovascular thoracic aneurysm repair via the carotid artery, in a patient with significant aorto-iliac and arch vessel disease.

Loss of elastic fiber integrity and reduction of vascular smooth muscle contraction resulting from the upregulated activities of matrix metalloproteinase-2 and -9 in the thoracic aortic aneurysm in Marfan syndrome

Thoracic aortic aneurysm (TAA) is the life-threatening complication of Marfan syndrome (MFS), a connective tissue disorder caused by mutations in the fibrillin-1 gene. TAA is characterized by degradation of elastic fiber, suggesting the involvement of matrix metalloproteinase (MMP)-2 and -9, the activation of which is regulated by TIMP (tissue inhibitor of MMP) types 1 and 2. We hypothesized that MMP-2 and -9 were upregulated during TAA formation in Marfan syndrome, causing loss of elastic fibers and structural integrity. We studied mice, from 3 to 12 months, heterozygous for a mutant Fbn1 allele encoding a cysteine substitution in fibrillin-1 (Fbn1(C1039G/+), designated as "Marfan" mice) (n=120), the most common class of mutation in Marfan syndrome. The littermates, Fbn1(+/+) served as controls (n=120). In Marfan aneurysmal thoracic aorta, mRNA and protein expression of MMP-2 and -9 were detected at 3 months and peaked at 6 months of age, accompanied by severe elastic fiber fragmentation and degradation. From 3 to 9 months, the MMP-2/TIMP-2 ratio increased by 43% to 63% compared with the controls. Dilated thoracic aorta demonstrated increased elasticity but distention caused a pronounced loss of contraction, suggesting weakening of the aortic wall. Breaking stress of the aneurysmal aorta was 70% of the controls. Contraction in response to depolarization and receptor stimulation decreased in the aneurysmal thoracic aorta by 50% to 80%, but the expression of alpha-smooth muscle actin between the 2 strains was not significantly different. This report demonstrates the upregulation of MMP-2 and -9 during TAA formation in Marfan syndrome. The resulting elastic fiber degeneration with deterioration of the aortic contraction and mechanical properties may explain the pathogenesis of TAA.

Aortic debranching procedures to facilitate endografting

Since approval of the Gore TAG device in 2005, endo-grafting of isolated descending thoracic aneurysms has been a welcome replacement to open surgery by many vascular and cardiac surgeons. Obvious constraints of this new technology are seal zones relative to adjacent brachiocephalic and visceral vessels. This is particularly important with regard to the more extensive thoracoabdominal aortic aneurysms. Although branched or fenestrated stent grafts have been used for such cases, these technically advanced devices are not available for general use and, therefore, many practitioners are left with few alternatives other than standard open repair. Some centers have tinkered with various forms of extra-anatomic bypass to lengthen seal zone sites and facilitate stent graft repair. The lack of uniformity and long-term data hamper acceptance of this approach. This review attempts to cull all available information on this technique from recent case reports and series published in the literature.

Bilateral axillary artery inflow in the treatment of a rare case of pseudocoartaction of the aortic arch

The axillary artery is the preferred site for arterial cannulation in operations for ascending aorta and aortic arch replacement in order to reduce perfusion-related morbidity in acute dissection and to prevent cerebral embolism in atherosclerotic aneurysm. We present the case of a patient with a chronic dissection presenting as pseudocoarctation of the aortic arch in which bilateral axillary artery inflow was necessary to perfuse both ascending and descending aorta.

Novel Way to Confirm Successful Endovascular Repair of a Thoracic Aortic Aneurysm Using a Remote Wireless Pressure Sensor

Due to the continuous risk of rupture from endoleaks after endoluminal graft repair of thoracic aneurysms, the need for lifelong postoperative surveillance has become necessary. Patients are put at a lifetime risk of radiation exposure and may be at an increased risk of contrast induced nephropathy from routine contrast use during follow-up computed tomography for postoperative surveillance of endoluminal grafts. Measuring aneurysm sac pressures using remote wireless pressure sensor may provide a noninvasive method to detect endoleak, procedural success, and long-term stent graft stability.

Cross-Sectional Imaging Studies: What Can We Learn and What Do We Need to Know?

Rapid, noninvasive imaging approaches can provide novel diagnostic information and, when effectively interpreted and implemented in a therapeutic strategy, can simplify procedures. Endovascular therapy of thoracic and abdominal aortic disease represents a dramatic shift in treatment of thoracoabdominal aortic disease, but one that requires a change in the knowledge base regarding both the morphology and pathophysiology of aortic disease and the interaction with interventional devices. As a result, the demands on cross-sectional imaging have increased commensurately with the complexity of the therapeutic options, but advances in cross-sectional imaging have kept pace. Current computed tomography (CT) and magnetic resonance imaging (MRI) technologies provide detailed morphologic assessment, and are advancing rapidly into more sophisticated physiologic evaluation of aortic disease. These advances may more effectively triage patients to appropriate therapy, or exclude patients from unnecessary invasive procedures. The information gleaned from CT and MRI studies is critical for the vascular surgeon who wants to identify appropriate vascular territories for intervention, plan a detailed approach, and develop sophisticated surveillance strategies.

Effectiveness of intensive medical therapy in type B aortic dissection: A single-center experience

OBJECTIVE

Although the mainstay of managing acute descending thoracic aortic dissection (ADTAD) remains medical, certain patients will require emergency surgery for complications of rupture or ischemia. This study evaluates factors that affect outcome and determines which patients previously treated surgically would have been eligible for endovascular repair.

METHODS

A single-institution retrospective study was conducted of patients who presented with clinical signs of ADTAD that was confirmed by magnetic resonance angiography (MRA) or computed tomography (CT). All patients were admitted to the intensive care unit (ICU) and medically managed to maintain systolic blood pressure<120 mm Hg and heart rate<70 beats/min. Two treatment groups were identified: group 1 received medical treatment only; group 2 received medical treatment plus emergency surgery. Patient demographic and clinical data were correlated with 30-day group mortality and morbidity and need for emergency surgery. The MRA and CT scan images of group 2 were retrospectively reviewed to determine if currently available endovascular treatment could have been done. The Fisher exact test was used to compare between the groups, and P<.05 was considered significant.

RESULTS

Between 1991 and 2005, 83 patients (55 men) were treated for ADTAD. The mean age was 67 years (range, 38 to 85). Sixty-eight patients (82%) had hypertension, three (3.6%) had Marfan syndrome, and 51 (62%) were smokers. Twenty-five (32%) of the patients were receiving beta-blocker therapy before the onset of their symptoms. Back pain was the most common initial symptom (72.2%). Emergency surgery was required in 19 patients (23%): 12 for rupture or impending rupture, four for mesenteric ischemia, and three for lower extremity ischemia. The need for emergency surgery was significantly higher in smokers (P=.03), in patients>70 years old (P=.035), and in patients who were not receiving beta-blocker therapy before the onset of symptoms (P=.023). The combined overall morbidity rate was 33%, and the mortality rate was 9.6%. Morbidity in group 2 was 64% and significantly higher than the 23% in group 1 (P=.00227). The mortality rate was also higher in group 2 at 31.5% compared with group 1 at 1.6% (P=.0004). Factors affecting the overall mortality included age>70 years (P=.057), previous abdominal aortic aneurysm repair (P=.018), tobacco use (P=.039), and the presence of leg pain at initial presentation (P=.013). As determined from the review of radiologic data, 11 of 13 patients with scans available for review in group 2 could have been treated with currently available endovascular grafts.

CONCLUSIONS

Intensive medical therapies are effective in preventing early mortality associated with ADTAD. Predictably, the need for emergency surgery carries a high morbidity and mortality rate. Most patients in this series requiring emergency surgery could have been candidates for endovascular therapy had it been available.

Hybrid approach to thoracoabdominal aortic aneurysms in patients with prior aortic surgery

OBJECTIVE

The hybrid approach to the repair of thoracoabdominal aortic aneurysm (TAAA), consisting of visceral aortic debranching with retrograde revascularization of the splanchnic and renal arteries and aneurysm exclusion using stent grafts, has been previously described and may be considered particularly appealing in high-risk patients, especially those who have undergone prior aortic surgery. This study analyzed prospectively recorded data of a series of high-risk patients with prior aortic surgery who underwent hybrid TAAA repair at our institute and contrasted the outcomes with those of a similar group of patients who underwent conventional open TAAA repair.

METHODS

Between 2001 and 2006, 13 patients (12 men) with a median age of 69.6 years (range, 35 to 82 years) underwent one-stage hybrid repair of TAAA (7 type I, 2 type II, 2 type IV, and 2 aneurysms of the visceral aortic patch). These patients, the hybrid group, had a history of aortic surgery (30.7% ascending, 30.7% descending, 46.1% abdominal aortic repair, and 15.4% redo TAAA) and were at high risk for open repair. The criteria used to define these patients as high risk and to indicate the need for hybrid treatment were American Society of Anesthesiologists (ASA) class 3 or 4 associated with a preoperative forced expiratory volume in 1 second (FEV1)<50%. In all cases, we accomplished partial or total visceral aortic debranching through (1) a previous visceral artery retrograde revascularization with synthetic grafts (single bypass, customized Y or bifurcated grafts), and (2) aortic endovascular repair with one of three different commercially produced stent grafts (Cook, W.L. Gore & Assoc, and Medtronic). We analyzed the results and compared the outcomes of the hybrid group with those of a similar group of 29 patients (25 men) with a median age 65.3 years (range, 58 to 79) selected from our overall series of 246 TAAA repairs between 1988 and 2005. These 29 patients, the conventionally treated group, were selected for having had aortic surgery (22% ascending, 38% descending, 42% abdominal aortic repair, and 10.3% redo TAAA), an ASA 3 or 4, a preoperative FEV1<50%, and a conventional open repair of TAAA (10 type I, 5 type II, 4 type III, 7 type IV, and 3 aneurysms of the visceral aortic patch).

RESULTS

In the hybrid group, 32 visceral bypasses were completed and endovascular TAAA repair was successful in all cases. No intraoperative deaths occurred. Perioperative mortality was 23%, and morbidity was 30.8% (renal failure in 2, respiratory failure in 1, and delayed transient paraplegia in 1). At a median follow-up of 14.9 months (range, 11 days to 59.4 months), all grafts were patent at postoperative computed tomography angiography and no aneurysm-related deaths, endoleak, stent graft migration, or morbidity related to visceral revascularization had occurred. No conventionally treated patients died intraoperatively. Perioperative mortality was 17.2% and morbidity was 44.8% (respiratory failure in 7, coagulopathy in 1, renal failure in 2, and paraplegia in 3). At a median follow-up of 5.4 years (range, 1.7 to 7.9 years), no significant complications related to aortic repair occurred, except for three patients (10.3%) with asymptomatic dilatation of the visceral aortic patch<5 cm undergoing radiologic surveillance.

CONCLUSION

Hybrid TAAA repair is technically feasible in selected cases. Perioperative morbidity and mortality were considerable in our subset of high-risk patients with prior aortic surgery, but no aneurysm-related or procedure-related complications were reported at mid-term follow-up. Hybrid TAAA repair did not lead to a significant improvement in outcomes compared with open TAAA repair in a similar group of patients. Larger series are required for valid statistical comparisons and longer follow-ups are necessary to evaluate the durability of hybrid repairs.

Preliminary retrograde visceral artery reconstruction for thoracoabdominal aortic aneurysms

The recent availability of thoracic endografts has expanded the options for treatment of thoracoabdominal aortic pathology. However, disease that involves the visceral aortic segment presents a special challenge due to the need to preserve mesenteric perfusion. We present three patients in whom preliminary retrograde visceral artery reconstruction was used as an adjunct prior to endovascular repair.

Die Analyse aortaler Hämodynamik und Gefäßwandparameter mittels fluss-sensitiver in-vivo 4D-MRT bei 3 Tesla

Modern phase contrast MR imaging at 3 Tesla allows the depiction of 3D morphology as well as the acquisition of time-resolved blood flow velocities in 3 directions. In combination with state-of-the-art visualization and data processing software, the qualitative and quantitative analysis of hemodynamic changes associated with vascular pathologies is possible. The 4D nature of the acquired data permits free orientation within the vascular system of interest and offers the opportunity to quantify blood flow and derived vessel wall parameters at any desired location within the data volume without being dependent on predefined 2D slices. The technique has the potential of overcoming the limitations of current diagnostic strategies and of implementing new diagnostic parameters. In light of the recent discussions regarding the influence of the wall shear stress and the oscillatory shear index on the genesis of arteriosclerosis and dilatative vascular processes, flow-sensitive 4D MRI may provide the missing diagnostic link. Instead of relying on experience-based parameters such as aneurysm size, new hemodynamic considerations can deepen our understanding of vascular pathologies. This overview reviews the underlying methodology at 3T, the literature on time-resolved 3D MR velocity mapping, and presents case examples. By presenting the pre- and postoperative assessment of hemodynamics in a thoracic aortic aneurysm and the detailed analysis of blood flow in a patient with coarctation we underline the potential of time-resolved 3D phase contrast MR at 3T for hemodynamic assessment of vascular pathologies, especially in the thoracic aorta.

Anotomic Interaction Between the Aortic Root and the Atrial Septum: A Prospective Echocardiographic Study

BACKGROUND

We recently demonstrated that patients with platypnea-orthodeoxia syndrome and an enlarged aortic root had a smaller and hypermobile atrial septum (AS) compared with those with a normal aortic root. However, this was a partly retrospective study.

METHODS

In all, 72 patients underwent transesophageal echocardiography and cardiac catheterization. The aortic root diameter, AS dimension, AS oscillation amplitude (ASo), and atrial pressure gradient were measured.

RESULTS

Significant correlations were found: aortic root diameter and AS dimension (r = -0.5, P < .001), aortic root diameter and ASo (r = +0.3, P = .014), AS dimension and ASo (r = -0.28, P = .02), and ASo and atrial pressure gradient (r = -0.36, P = .003). Nineteen patients presented with patent foramen ovale; those with grade 3 shunting had significantly higher mobility of the AS and larger aortic roots.

CONCLUSION

These results confirm that an increasing aortic size affects the AS by decreasing its apparent size and increasing its mobility. In case of a patent foramen ovale, increased AS mobility is associated with greater shunting.

Natural History of Ascending Aortic Aneurysms in the Setting of an Unreplaced Bicuspid Aortic Valve

BACKGROUND

Patients with bicuspid aortic valve (BAV) are at risk for valvular disease and ascending aortic aneurysms and dissections. Although others have investigated the need for concomitant repair, the natural history of aortic disease has not been addressed.

METHODS

A review of our institutional clinical database identified 514 patients (326 male, 188 female) with unrepaired ascending aortic aneurysms followed from 1985 to 2005. Seventy patients (13.4%) diagnosed with BAV form group A; the remaining 445 patients form group B. Growth rates and risk factors for complications were assessed.

RESULTS

Patients in group A had a lower incidence of hypertension (p = 0.0185), carotid artery disease, and stroke (p = 0.0184), and presented at an earlier age (49.0 versus 64.2 years, p < 0.0001). Group A also had a higher rate of aortic growth (0.19 versus 0.13 cm/year, p = 0.0102). The incidence of rupture and dissection were similar. Overall survival was better among patients with BAV (p < 0.0001). Among patients with BAV, those with aortic stenosis had a higher risk of rupture, dissection, or death before operative repair than did those with normally functioning valves (odds ratio 10.475, 95% confidence interval: 1.153 to 95.155).

CONCLUSIONS

Aortic stenosis presents a significant added risk for patients with aneurysmal disease in the face of BAV. Despite faster rates of growth, however, patients with BAV have similar rates of aortic rupture, dissection, and death and improved long-term survival. Contributing to this finding may be the lower incidence of comorbidities, the younger age at presentation, and the more attentive follow-up with earlier operative repair.

Usefulness of transcranial motor evoked potentials during thoracoabdominal aortic surgery

BACKGROUND

The purpose of this study was to evaluate the efficacy of myogenic transcranial motor evoked potentials (tc-MEPs) for spinal cord ischemia in the repair of descending thoracic or thoracoabdominal aortic aneurysms.

METHODS

Intraoperative tc-MEPs was used in 72 patients who underwent the repair of descending thoracic (n = 24) or thoracoabdominal aortic aneurysms (n = 49) classed as Crawford I in 10 patients, II in 12, III in 23, and IV in 3. There were 52 men and 20 women, and their mean age was 64.9 +/- 12.8 years. Tc-MEPs were recorded by transcranial electrical stimulation and compound muscle action potentials.

RESULTS

The hospital mortality rate was 5.6% (n = 4), and the incidence of neurologic deficits was 11.1% (n = 8). All patients whose MEP amplitude recovered to more than 75% of the baseline showed normal spinal function, and 8 of 9 patients whose MEP amplitude decreased to below 75% of the baseline at the end of the procedure showed neurologic deficits postoperatively. The sensitivity of tc-MEPs was 100% and specificity was 98.4%. Latency in patients with postoperative paraplegia was 123% +/- 9% and was significantly prolonged at the end of the procedure.

CONCLUSIONS

Tc-MEPs were very sensitive and specific to spinal cord ischemia with reduced amplitude and prolongation of the latency period. Tc-MEPs are considered a useful monitor of spinal cord ischemia during descending thoracic or thoracoabdominal aortic surgery.

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.

Outcome after celiac artery coverage during endovascular thoracic aortic aneurysm repair: Preliminary results

BACKGROUND

Endovascular repair of descending thoracic aortic aneurysms has emerged as an alternative to open repair. Coverage of the left subclavian origin has been reported to expand the proximal sealing zone. We report the planned coverage of the celiac artery origin with a thoracic stent graft to achieve an adequate distal sealing zone.

METHODS

All patients undergoing endovascular aneurysm repair are prospectively entered into a computerized database. All patients who underwent thoracic endovascular aneurysm repair with coverage of the celiac artery origin were identified and retrospectively analyzed. End points for evaluation included indications for covering the celiac artery, anatomic features of the distal landing zone, demonstration of collateral circulation between the celiac artery and the superior mesenteric artery, technical success of the procedure, and presence of clinical ischemic symptoms after the procedure.

RESULTS

Between March 2005 and May 2006, 46 patients underwent endovascular repair of descending thoracic aortic aneurysms. Seven patients had planned celiac artery coverage with a thoracic stent graft to secure an adequate distal sealing zone. Six patients demonstrated collateral circulation through the gastroduodenal artery between the celiac and superior mesenteric arteries before deployment of the stent graft. One patient had a distal type I endoleak at the conclusion of the procedure related to inadequate sealing at the superior mesenteric artery origin. No type II endoleaks were evident at the final intraoperative angiogram or 30-day computed tomography scan. There were no postoperative deaths, no ischemic abdominal complications, and no clinical spinal cord ischemia. Short-term follow-up (1 to 10 months) has demonstrated no additional endoleaks (type I not fully assessed), no aneurysm growth, and no aneurysm ruptures.

CONCLUSION

This limited series supports the suitability, in selected patients, of covering the celiac artery origin for a distal landing zone when the distal sealing zone proximal to the celiac artery is inadequate. We recommend the angiographic evaluation of the collateral circulation between the celiac and superior mesenteric arteries when covering the celiac artery origin is being considered.

Preservation of Renal Function Utilizing Hypothermic Circulatory Arrest in the Treatment of Distal Thoracoabdominal Aneurysms (Types III and IV)

Although left heart bypass and hypothermia are often used in the performance of type I and type II thoracoabdominal aneurysms (TAAs), most of these more distal aneurysms are done utilizing the clamp and sew technique. Renal failure occurs between 8.6% to 39% in recent series of patients following surgery for type III and IV TAAs. The purpose of this study was to determine whether the use of hypothermic circulatory arrest in these cases would serve to protect renal function. All patients were operated on using hypothermic circulatory arrest. The kidneys were perfused with cold blood during the procedures, and renal artery bypasses were aggressively used (when stenoses greater than 50% were observed). The series describes 33 consecutive patients with type III and IV TAAs who were operated on utilizing hypothermic circulatory arrest with a core temperature of 15 degrees centigrade. All visceral and renal arteries were individually perfused; 20 patients had bypass grafts of their renal artery stenoses. Although six patients had renal failure preoperatively, only one developed postoperative renal failure. This was the patient who was operated on as an emergency for severe abdominal pain, back pain, and acidosis who was also the only hospital death. Of the remaining five patients with elevated creatinines preoperatively, four had postoperative decrease of the serum creatinine. One patient developed paraparesis and one developed a stroke. The median length of stay was 8 days. Consideration should be given to the use of hypothermic circulatory arrest in type III and IV TAAs for the preservation of renal function and improved overall results.

Fenestrated endovascular grafts for juxtarenal aortic aneurysms: A step by step technical approach

Fenestrated endovascular aortic aneurysm repair is a valuable alternative for patients who are at high risk for open surgery, but have unsuitable anatomy for infrarenal endovascular repair due to a short aneurysmal neck. Recognizing that this is an evolving and complex technology, we present a step by step approach to the surgical technique that may be useful for endovascular therapist interested in the management of these complex patients.

Proteinase systems and thoracic aortic aneurysm progression

Thoracic aortic aneurysms (TAAs) are a rare but potentially devastating condition. Current surgical treatment of TAAs usually involves a major operation, which conveys many risks to the patient. Better knowledge of the cellular events that lead to aneurysm formation may elucidate less morbid treatment options for this condition. A number of recent studies have identified that the relative abundance and activity of extracellular matrix (ECM) proteolytic systems are increased with TAAs. Specifically, the matrix metalloproteinases (MMPs) have been linked through numerous studies to TAA formation. MMPs comprise a family of ECM-degrading proteinases. Endogenous tissue inhibitors (TIMPs) normally regulate MMP activity, and the activation of MMPs is complex and tightly controlled. Aneurysm formation may be related to relative changes in the balance between MMP/TIMP abundance favoring proteolysis. Through ECM degradation, the medial layer will undergo structural remodeling and a loss of structural integrity, leading to TAA formation. The goals of this review are to examine the structure of the normal and aneurysmal thoracic aorta and to place the new findings regarding ECM proteolysis in perspective with regard to TAA formation and progression. Through an integration of basic and clinical studies regarding the underlying molecular basis for proteolysis of the thoracic aorta, improved diagnostic, prognostic, and therapeutic strategies for this disease process are likely to be realized.

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.

Assessment of Spinal Cord Circulation and Function in Endovascular Treatment of Thoracic Aortic Aneurysms

BACKGROUND

In thoracic stent graft repair, the importance of segmental artery (SA) occlusion and the role of blood pressure management during the intraoperative and directly postoperative period are not clear. To study these aspects in relation to spinal cord ischemia, our protocol in the endovascular treatment of descending thoracic aneurysms covering segmental arteries T8 and lower includes preoperative assessment of the spinal cord circulation using magnetic resonance angiography, intraoperative cerebrospinal fluid drainage, and spinal cord function monitoring using motor evoked potentials (MEPs).

METHODS

Thirteen patients with thoracic aortic aneurysms and dissections needing stent graft coverage of T8 and lower were included. In 9 patients, spinal cord circulation was evaluated preoperatively by magnetic resonance angiography. In 12 patients, MEPs were recorded during the endovascular procedure. A combination of both techniques was used in 8 patients.

RESULTS

The distal stent graft landing zone covered the intercostal arteries up to T10 in 4 patients, up to T11 in 7 patients, up to T12 in 1 patient, and all SAs to the aortic bifurcation in 1 patient. In 6 patients, the SA feeding the Adamkiewicz artery was covered by the stent graft. In three patients, intersegmental collaterals were present to the SA feeding the Adamkiewicz artery. The MEPs decreased to 50% and 30% in 2 patients, recovering to levels above 50% by elevation of the mean arterial pressure. Postoperatively, no signs of paraplegia were present.

CONCLUSIONS

We believe that the presence of intersegmental collaterals decreases the risk of spinal cord ischemia during endovascular thoracic aortic aneurysm repair. Monitoring of MEPs during endovascular thoracic procedures shows no decrease in most cases. However, if a decrease of MEPs occurs, this can be reversed by elevation of the mean arterial pressure.

Early Surgical Experience With Loeys-Dietz: A New Syndrome of Aggressive Thoracic Aortic Aneurysm Disease

BACKGROUND

Loeys-Dietz syndrome (LDS) is a recently described genetic aortic aneurysm syndrome resulting from mutations in receptors for the cytokine transforming growth factor-beta. Phenotypic features include a bifid uvula, hypertelorism, cleft palate, and generalized arterial tortuosity, but risk of thoracic aortic rupture and dissection is the principle focus of management and exceeds that of most known connective tissue disorders. Our surgical experience with LDS was reviewed to assess outcomes and develop guidelines for management of this aggressive disease.

METHODS

We retrospectively reviewed medical records of all LDS patients from two institutions and obtained follow-up data from medical records and patient contacts.

RESULTS

Clinical criteria and genotyping were used to identify 71 patients. Before surgical intervention, 6 patients (9%) died from aneurysm rupture or dissection, which occurred in several patients with aortic diameters of less than 4.5 cm and as early as 6 months of age. Thoracic aortic aneurysm surgery was performed in 14 children and 7 adults. Operations included valve-sparing root replacement (VSRR) in 13, Bentall procedure in 5, arch replacement in 2, and VSRR with arch replacement in 1. There were no deaths at the primary operation, although 3 patients died 2, 5, and 11 years after surgery from rupture of the descending thoracic (n = 2) or abdominal aorta (n = 1).

CONCLUSIONS

LDS is an aggressive aortic aneurysm disease with a propensity toward rupture and dissection at a younger age and smaller aortic diameters than in other connective tissue disorders, particularly in the ascending aorta. Early recognition of the phenotype, prophylactic intervention, and meticulous surveillance of the distal aorta and vascular tree are warranted for optimal management.

Spinal Cord Perfusion and Protection During Descending Thoracic and Thoracoabdominal Aortic Surgery: The Collateral Network Concept

In the last two decades, as an increasing number of patients with descending thoracic and thoracoabdominal aneurysms are being diagnosed and treated, a more sophisticated understanding of spinal cord perfusion has become important in the attempt to minimize the frequency of spinal cord injury. The synthesis of information from laboratory studies and clinical experience has led to the collateral network concept, a framework for understanding spinal cord perfusion and thereby improving spinal cord protection during treatment of aneurysmal disease of the aorta distal to the left subclavian artery. Application of principles based on the collateral network concept has resulted in falling rates of spinal cord injury, which now approach 1% in descending thoracic aneurysm resection and less than 10% in extensive thoracoabdominal resections. These accomplishments suggest that, with further investigation, routine sacrifice of segmental aortic branches can be carried out in a way that will allow surgical and endovascular therapy of extensive distal aortic aneurysms without neurologic injury.

Fenestrated and Branched Stent-grafting After Previous Surgery Provides a Good Alternative to Open Redo Surgery

OBJECTIVE

To present our experience using fenestrated and branched endoluminal grafts for Para-anastomotic aneurysms (PAA) following prior open aneurysm surgery, and after previous endovascular aneurysm repair (EVAR) complicated by proximal type I endoleak.

METHODS

Fenestrated and/or branched EVAR was performed on eleven patients. Indications included proximal type I endoleak after EVAR and short infrarenal neck (n=4), suprarenal aneurysm after open AAA (n=4), distal type I endoleak after endovascular TAA (n=1), proximal anastomotic aneurysm after open AAA (n=1), and an aborted open AAA repair due to bleeding around a short infrarenal neck.

RESULTS

The operative target vessel success rate was 100% (28/28) with aneurysm exclusion in all patients. Mean hospital stay was 6.0 days (range 2-12 days, SD 3.5 days). Thirty day mortality was 0%. All cause mortality during 18 months mean follow-up (range 5-44 months, SD 16.7 months) was 18% (2/11) with no deaths from aneurysm rupture. Cumulative visceral branch patency was 96% (27/28) at 42 months. Average renal function remained unchanged during the follow-up period.

CONCLUSIONS

Our report highlights the potential of fenestrated and branched technology to improve re-operative aortic surgical outcomes. The unique difficulties of increased graft on graft friction hindering placement, short working distance, and increased patient co-morbidities should be recognized.

Hybrid-procedures for the Treatment of Thoracoabdominal Aortic Aneurysms and Dissections

AIM

The conventional open repair of thoracoabdominal aneurysms and dissections remains complex and demanding and is associated with significant morbidity and mortality. We present our experience of hybrid open and endovascular treatment of thoracoabdominal aneurysms and dissections.

METHODS

Within an experience of 226 aortic stent-grafts between 1998 and April 2006, 6 of the patients (median age 60 years, range 35 to 68 years) with thoracoabdominal aneurysms (Crawford type I, II, III, and V) were treated with a combined endovascular and open surgical approach. Five men and one woman, with median aneurysm diameter of 75 mm (range 70-100 mm), received revascularization of the renal arteries, the superior mesenteric artery, and the coeliac trunk accomplished via transperitoneal bypass grafting. Aneurysmal exclusion was then performed by stent-graft deployment.

RESULTS

The entire procedure was technically successful in all patients. The patients were discharged a median of 9 days after the operation, while the postoperative studies revealed the patency of the vessels and no evidence of type I endoleak or secondary rupture of the aneurysm. During follow up (1 to 22 months) spiral-CT scanning revealed distinct shrinkage of the aneurysm, no graft migration or endoleak and patency of all revascularised vessels, except one renal artery in two patients. No patient experienced any temporary or permanent neurological deficit, and no dialysis was necessary.

CONCLUSION

The combined endovascular and open surgical approach is feasible, without cross clamping of the aorta and with minimized ischemia time for renal and visceral arteries, and seems to be an appropriate strategy for patients with a thoraco-abdominal aortic aneurysm or dissection.

[Clinical and special diagnosis of aneurysms of descending and thoracoabdominal aorta]

Clinical and special diagnosis of aneurysms of descending and thoracoabdominal aorta is discussed. Polymorphism and non-specificity of clinical symptoms (clinical masks to 31.9%), asymptomatic forms (to 55.5%) demand special diagnostic methods for right diagnosis and choice of surgery type.

Thoracic aneurysm rupture presenting as a rapidly enlarging neck mass

A rapidly enlarging neck mass is an unusual clinical complaint at the emergency department. We report a case of an acute left neck swelling caused by a haematoma from a ruptured thoracic aneurysm. This resulted in dynamic airway distortion and obstruction and posed a great challenge to airway management.

Patency of distal false lumen in acute dissection: extent of resection and prognosis

We assessed the hypotheses that extension of aortic replacement would reduce the patency of the false lumen of the descending aorta and that postoperative patency of the false lumen would result in poor prognosis. One hundred and twenty-four consecutive patients underwent surgical repair for acute type A acute dissection on an emergency basis. Among the 124 patients, 89 patients had De Bakey type I dissection. Among the patients with De Bakey type I dissection, the false lumen of the descending aorta was preoperatively patent in 52 patients. Distal extent of aortic replacement was ascending aorta in 16 patients, hemiarch in 15 patients, partial arch in seven patients, and total arch in 11 patients. Patency of the false lumen was not influenced by distal extent of the aortic replacement. In a one-year follow-up, the maximum diameter of the descending aorta with patent false lumen had increased significantly than that with closed false lumen. Survival rates were 96% at one year and 67% at five years in the patients with patent false lumen and no mortality in the patients with closed false lumen. Patency of the false lumen was not influenced by extension of aortic replacement and associated with poor prognosis.

Combined Use of Adamkiewicz Artery Demonstration and Motor-Evoked Potentials in Descending and Thoracoabdominal Repair

BACKGROUND

We retrospectively reviewed the outcome of distal descending aortic and thoracoabdominal aortic repair with preoperative identification of the Adamkiewicz artery by magnetic resonance angiography and intraoperative monitoring of transcranial motor-evoked potentials.

METHODS

We began combined use of demonstration of the Adamkiewicz artery and intraoperative recording of motor-evoked potentials for prevention of spinal cord complications in descending and thoracoabdominal aortic aneurysm repair in 1998. Ninety-two consecutive patients were studied, with descending aneurysm in 53 and thoracoabdominal aneurysm in 39 patients. The repair was performed through a left thoracic or thoracoabdominal incision, using partial cardiopulmonary bypass to prevent spinal cord injury. Magnetic resonance angiography revealed the Adamkiewicz artery in 70.7% of cases. During surgery, spinal cord ischemia was monitored using motor-evoked potentials. Anastomoses were performed using a segmental clamp technique to reduce spinal cord ischemic time. Based on the findings of magnetic resonance angiography and motor-evoked potentials, the Adamkiewicz artery and other relevant intercostals and lumbar arteries were revascularized or preserved, or both.

RESULTS

The mean durations of partial cardiopulmonary bypass, cross-clamping, and surgery, respectively, were 144.4 +/- 232.2, 106.0 +/- 65.5, and 411.8 +/- 170.7 minutes. Three hospital deaths (3.3%) occurred in patients with a thoracoabdominal aortic aneurysm. Motor-evoked potentials changed in 9 patients (9.8%), in 8 (88.9%) of whom they were eventually restored. Although paraplegia developed in 1 patient (1.1%) with a mycotic descending aneurysm, the other patients survived without spinal cord injury.

CONCLUSIONS

Combined visualization of the Adamkiewicz artery and determination of motor-evoked potentials are useful in preventing spinal cord injury in descending and thoracoabdominal aortic repair.

Progression rate of ascending aortic dilation in patients with normally functioning bicuspid and tricuspid aortic valves

Dilation of the ascending aorta (AA), which is disproportionate to associated valvular lesions, is a relatively well-recognized phenomenon in patients with a bicuspid aortic valve (BAV). The aim of this study was to evaluate the rate of changes in the AA dimensions and the outcome in patients with AA dilation and BAVs compared with patients with AA dilation and tricuspid aortic valves (TAVs). Serial transesophageal echocardiograms (>12 months apart) were performed in 113 consecutive patients (BAV, n=27 and TAV, n=86) with AA diameters of >or=40 and <or=60 mm, respectively, without associated significant aortic valve stenosis or regurgitation. Baseline diameters at the sinuses of Valsalva (SV), the sinotubular junction (STJ), and the tubular tract (TT) were similar in both groups (41.3+/-5.3 vs 42.3+/-6.3 mm, p=NS, 37.8+/-5.2 vs 38.7+/-5.5 mm, p=NS, and 47.3+/-5.3 vs 45.9+/-5.1, p=NS, respectively). During an average 3-year follow-up, the rate of AA diameter progression was similar for the BAV and TAV groups (0.86+/-0.81 vs 0.82+/-1.1 mm/year, p=NS for the SV; 1.06+/-1.6 vs 0.63+/-1.1 mm/year, p=NS for the STJ; and 0.81+/-1.1 vs 0.75+/-1.1 mm/year, p=NS for the TT, respectively). Three patients in the TAV group experienced cardiac death (2 died suddenly and 1 after emergency surgery for AA dissection); there was no occurrence of cardiac death in the BAV group. In conclusion, the rate of progression of AA aneurysms was similar in patients with BAVs and in those with TAVs. Furthermore, patients with BAVs did not have increased rates of AA related complications compared with patients with TAVs.

Dynamic cine-CT angiography for the evaluation of the thoracic aorta; insight in dynamic changes with implications for thoracic endograft treatment

OBJECTIVE

Thoracic aneurysm preoperative imaging is performed using static techniques without consideration of normal aortic dynamics. Improved understanding of the native aortic environment into which thoracic endografts are placed may aid in device selection. It is unclear what comprises normal thoracic aortic pulsatility. We studied these phenomena dynamically using ECG-gated 64-slice CTA.

METHODS

Maximum diameter and area change per cardiac cycle was measured at surgically relevant anatomic thoracic landmarks in ten patients; 1.0 cm proximal and distal to the subclavian artery, 3.0 cm distal to the subclavian artery, and 3.0 cm proximal to the celiac trunk. Data was acquired using a novel ECG-gated dynamic 64-slice CT scanner during a single breath hold with a standard radiation dose and contrast load. Eight gated data sets, covering the cardiac cycle were reconstructed, perpendicular to the central lumen.

RESULTS

There is impressive change in both maximum diameter and area in the thoracic aorta during the cardiac cycle. Mean maximum diameter changes of greater than 10% are observed in the typical sealing zones of commercially available endografts corresponding to diameter increases of up to 5mm. Aortic area increases by over 5% per cardiac cycle.

CONCLUSIONS

ECG-gated dynamic CTA with standard radiation dose is feasible on a 64-slice scanner and provides insight into (patho) physiology of thoracic aortic conformational changes. Clinicians typically oversize thoracic endografts by 10%. With aortic pulsatility resulting in diameter changes of up to 17.8%, the potential exists for endograft undersizing, graft migration, intermittent type I endoleak, and poor patient outcome. Furthermore, aortic pulsatility is not evenly distributed, and non-circular stentgraft designs should be considered in the future since aortic distension in the aneurysm neck is not evenly distributed.

Dynamic aortic obstruction in a patient with acute type B dissection

There are at least 7000 aortic dissections diagnosed in the United States each year. Type B dissections accounted for 38% of cases enrolled in the prospective International Registry of Aortic Dissection. We report a case of a 48-year-old hypertensive woman with an acute type B aortic dissection causing significant dynamic obstruction of the aorta. Intravascular ultrasound of her aorta revealed a mobile intimal flap nearly obliterating the true lumen with each systolic contraction. Simultaneous pressure tracings obtained from her ascending aorta and femoral artery demonstrated a systolic pressure gradient in excess of 100 mm Hg. The patient developed progressive renal failure and ultimately underwent successful operative replacement of the proximal descending thoracic aorta with a Dacron graft. In this case presentation, we highlight the unusual physiology exemplified by this case and explore contemporary management strategies for complicated type B aortic dissection, including surgery and catheter-based techniques.

Aortic operation after previous coronary artery bypass grafting

OBJECTIVES

Aortic surgery for progressive aortic valve disease or aortic aneurysm after previous coronary artery bypass grafting (CABG) is a challenging procedure. We report the outcome of aortic reoperation after previous CABG and evaluate our management of patent grafts and our methods for obtaining myocardial protection.

METHODS

From February 2001 to July 2003, 6 patients with progressive aortic valve disease and aneurysm of the thoracic aorta were operated on. The group comprised 3 men and 3 women with a mean age of 67.6 years. There were 4 patients with an aneurysm of the aortic arch, 1 with chronic ascending aortic dissection, and 1 with progressive aortic valve stenosis. The interval between previous CABG and aortic surgery was 74.0 +/- 44.2 months. All reoperations were performed via median resternotomy. Myocardial protection was obtained by hypothermic perfusion of patent in-situ arterial grafts following cold-blood cardioplegia administration via the aortic root under aortic cross clamping.

RESULTS

The operative procedure was aortic arch replacement in 4 patients, ascending aortic replacement with double CABG in 1, and aortic valve replacement in 1. All patients survived the reoperation. Postoperative maximum creatine kinase-MB was 49.2 +/- 29.8 and no new Q-waves occurred in the electrocardiogram nor were any new wall motion abnormalities recognized on echocardiography. There were no late deaths during a follow-up of 30.7 months.

CONCLUSION

Reoperative aortic procedures after CABG can be performed safely with myocardial protection via hypothermic perfusion of a patent in-situ arterial graft.