Himanshu J. Patel

Patient selection for left ventricular assist device therapy

Patient selection for left ventricular assist device (LVAD) therapy is the most important process in obtaining a successful outcome. Evaluation requires assessing the appropriateness for device implantation based on need and risk of LVAD implant to the patient. Appropriate patients can be selected without the need for invasive hemodynamic measurements and selection can be based on symptoms, appropriateness of medical therapy, and on the need for inotropic therapy. Assessing the risk of LVAD therapy to the patient requires evaluating the degree of organ dysfunction and technical factors. Patients should be offered the option of LVAD therapy if they meet criteria for need, possess the potential for organ recovery, and have appropriate operative risk.

Operative delay for peripheral malperfusion syndrome in acute type A aortic dissection: a long-term analysis.

BACKGROUND We previously reported an improvement in early mortality for patients presenting with acute type A dissection with malperfusion using a strategy of initial percutaneous intervention to restore end-organ perfusion and delayed operative repair after resolution of the malperfusion syndrome. This study evaluates the late outcomes with this approach. METHODS A total of 196 patients were admitted with acute type A dissection (1997-2007). Seventy patients with ischemic end-organ dysfunction underwent percutaneous fenestration or branch vessel stenting. Operative therapy was planned after resolution of the reperfusion injury. Outcomes were compared for patients with (MP) and without (UC) dissection with ischemic end-organ dysfunction. RESULTS The mean age of the patients was 57.1 years, and 173 patients underwent operative repair (n = 126 UC group; n = 47 MP group). The remaining 23 patients in the MP group died before repair from complications of malperfusion (11) or aortic rupture (12) while awaiting resolution of the malperfusion syndrome. Operative mortality was seen in 9.2% of all patients (9.5% in UC group vs 8.5% in MP group; P = 1.0). On analysis of the entire cohort (n = 196), the mean survival was higher for the uncomplicated group (95.9 months for UC group vs 53.7 months for MP group; P < .001). A subgroup analysis of patients who underwent operation (n = 173) revealed similar mean survival (95.9 months for UC group vs 80.5 months for MP group; P = .45). CONCLUSION A strategy of immediate reperfusion, stabilization, and planned operative repair for acute type A dissection with malperfusion still carries a significant risk for early and late mortality. However, those patients who survive the initial malperfusion and undergo repair have a similar operative and late survival when compared with those patients presenting with uncomplicated dissection.

Ascending and Arch Aorta Pathology, Natural History, and Treatment

Aortic aneurysms are the 13th-leading cause of mortality in the United States.1 The incidence of thoracic aortic aneurysms (TAA) is increasing with improvements in screening, as well as advances in imaging.2 Replacement of the ascending aorta accounts for the majority of thoracic aortic procedures. TAAs are more frequently present in men and typically occur in the 50- to 70-year age range.3 Disease processes affecting the ascending and arch aorta include degenerative aneurysms and aneurysms associated with connective tissue disease, as well as acute aortic dissection and its variants of intramural hematoma and penetrating ulcer. Syphilitic aneurysms, once the predominant cause of ascending aneurysms, are exceedingly rare today. In the present review, we will discuss these pathological conditions as well as operative techniques and outcomes after medical and operative therapy. ### Degenerative Aneurysms Degenerative aneurysms comprise the majority of those seen in the ascending aorta and have a specific pathological profile.3 Whereas the elastin content in the ascending aorta is high, that seen in ascending aortic aneurysms is significantly reduced. In addition, the media of the aneurysm displays a loss of smooth muscle cells and fragmentation of the elastic fibers from a process known as cystic medial degeneration. Although this process is seen normally as a consequence of aging, it is accelerated in some and results in the phenotypic expression of an ascending aortic aneurysm. Recent studies have focused on differences in ascending aneurysm pathogenesis for patients with bicuspid and tricuspid aortic valves, with the former suggested as a more-aggressive variant.4 ### Marfan Syndrome Marfan syndrome is the most common inherited connective tissue disease, with an incidence of 1 in 10 000.5 The basic genetic defect is a mutation of the gene for fibrillin-1, an essential protein of microfibrils. The phenotypic manifestation is that of disorganized elastic fibers, premature cystic medial …

Open arch reconstruction in the endovascular era: analysis of 721 patients over 17 years.

OBJECTIVE Recent advancements in thoracic endovascular aortic repair, such as branched endografts or hybrid debranching/thoracic endovascular aortic repair, have extended the option of endoluminal therapy into the realm of the aortic arch. A contemporary assessment of open arch repair to provide long-term data for comparative analysis for these newer therapies is timely, warranted, and presented in this article. METHODS Since the inception of our thoracic endovascular aortic repair program in 1993, 721 patients (mean age of 59.3 years, 68.9% were male) have undergone median sternotomy and open arch reconstruction with hypothermic circulatory arrest. Extended arch repair was performed in 42.7% with construction of bypasses to the innominate (296 patients), left carotid (216 patients), and subclavian (75 patients) arteries or elephant trunk procedures (42 patients). Concomitant aortic valve or aortic root replacement was required in 403 patients, and root reconstruction was required in 222 patients. Retrograde (641 patients) or antegrade (400 patients) cerebral perfusion was used for neuroprotection during hypothermic circulatory arrest. The operative procedure was urgent or emergency in 316 patients (43.8%) and included repair of type A dissection in 284 patients (39.3%). A total of 111 patients (15.4%) had undergone prior cardiac surgery. Primary outcomes in this study were early and late mortality. Follow-up was 100% complete (mean, 52.6 months). RESULTS Thirty-day morbidity included death (36 patients [5%]), stroke (34 patients [4.7%]), and permanent dialysis (14 patients [1.9%]). Independent predictors of early mortality included advancing age, prolonged bypass times, and impaired ejection fraction (all P < .05). Actuarial survival at 10 years was 65%. Independent predictors of late mortality included advancing age, prolonged lower body circulatory arrest times, and increasing creatinine (all P < .05). By Kaplan-Meier analysis, 10-year survival was significantly reduced after operative procedures for type A dissection (non-type A 69.1% vs type A 58%, P = .003). Freedom from aortic reoperation (any segment) was 72.6% at 10 years. CONCLUSIONS Open aortic arch repair can be accomplished with excellent early and late results. These outcomes provide objective data for comparison and suggest that newer endovascular therapies should be evaluated first in high-risk groups, such as those with advanced age or impaired renal function before broader application in all patients.

Clinical presentation, management, and short-term outcome of patients with type A acute dissection complicated by mesenteric malperfusion: Observations from the International Registry of Acute Aortic Dissection

BACKGROUND Few data exist on clinical/imaging characteristics, management, and outcomes of patients with type A acute dissection and mesenteric malperfusion. METHODS Patients with type A acute dissection enrolled in the International Registry for Acute Dissection (IRAD) were evaluated to assess differences in clinical features, management, and in-hospital outcomes according to the presence/absence of mesenteric malperfusion. A mortality model was used to identify predictors of in-hospital mortality in patients with mesenteric malperfusion. RESULTS Mesenteric malperfusion was detected in 68 (3.7%) of 1809 patients with type A acute dissection. Patients with mesenteric malperfusion were more likely to be older and to have coma, cerebrovascular accident, spinal cord ischemia, acute renal failure, limb ischemia, and any pulse deficit. They were less likely to undergo surgical/hybrid treatment (52.9% vs 87.9%) and more likely to receive only medical (30.9% vs 11.6%) or endovascular (16.2% vs 0.5%) management (P < .001). Overall in-hospital mortality was 63.2% and 23.8% in patients with and without mesenteric malperfusion, respectively (P < .001). In-hospital mortality of patients with mesenteric malperfusion receiving medical, endovascular, and surgical/hybrid therapy was 95.2%, 72.7%, and 41.7%, respectively (P < .001). At multivariate analysis, male gender (odds ratio [OR], 1.7; P = .002), age (OR, 1.1/y; P = .002), and renal failure (OR, 5.9; P = .020) were predictors of mortality whereas surgical/hybrid management (OR, 0.1; P = .005) was associated with better outcome. CONCLUSIONS Type A acute aortic dissection complicated by mesenteric malperfusion is a rare but ominous complication carrying a high risk of hospital mortality. Surgical/hybrid therapy, although associated with 2-fold hospital mortality, appears to be associated with better long-term outcomes in the management of type A acute aortic dissection in this setting.

Hybrid debranching with endovascular repair for thoracoabdominal aneurysms: a comparison with open repair.

BACKGROUND Hybrid visceral-renal debranching procedures with endovascular repair have recently been proposed as a less invasive alternative to conventional thoracoabdominal aortic aneurysm (TAAA) surgery. This study provides a concurrent assessment of hybrid and open TAAA repair. METHODS One hundred two consecutive patients (mean age, 63.0 years) underwent open (73) or hybrid (29) Crawford type 1 (19), 2 (50), or 3 (33) TAAA repair from 2000 to 2009. Hybrid debranching procedures were selected for patients considered poor operative risk for standard TAAA repair (27) or for patient preference (2). The TAAAs were fusiform atherosclerotic (68), dissection (30), or pseudoaneurysm (4). Fifty-seven patients (55.9%) had previously undergone aortic repair. Outcomes were analyzed with 100% follow-up (mean, 30.5 months). RESULTS Operative procedures were urgent or emergent in 16 (15.6%). Early mortality occurred in 13 (12.7%), and was independently predicted by use of hypothermic circulatory arrest (p = 0.005). Early morbidity included permanent paraplegia (12), stroke (1), need for dialysis (22), or tracheostomy (7). Independent correlates of a composite outcome comprised of early mortality and these early morbidities included an urgent-emergent presentation (p = 0.002) or open TAAA repair (p = 0.021). Kaplan-Meier survival was similar between open and hybrid TAAA groups (p = 0.88). Late mortality was independently predicted by the presence of diabetes (p = 0.052) or the need for dialysis at the time of TAAA repair (p < 0.001). CONCLUSIONS Hybrid debranching procedures may reduce early morbidity and yield similar late survival, even in a group considered high risk for open surgery. These data support the increasing utilization of a hybrid debranching and endovascular approach for patients requiring thoracoabdominal aneurysmectomy.

Long-term results of percutaneous management of malperfusion in acute type B aortic dissection: Implications for thoracic aortic endovascular repair

OBJECTIVE Open repair for acute type B dissection with malperfusion is associated with significant morbidity. Thoracic aortic endovascular repair has been proposed as a less-invasive therapy for acute type B dissection with malperfusion. Benefits of thoracic aortic endovascular repair include the potential for false lumen thrombosis. Its risks include both early morbidity and mortality, and uncertain late results with potentially unstable landing zones. We present the first long-term analysis of an alternative endovascular approach consisting of percutaneous flap fenestration with true lumen and branch vessel stenting to restore end-organ perfusion. METHODS Outcomes were analyzed for 69 patients presenting with acute type B dissection with malperfusion from 1997 to 2008. All patients were evaluated with angiography and treated with a combination of flap fenestration, true lumen, or branch vessel stenting where appropriate. RESULTS Mean age was 57.3 years. Identified malperfused vascular beds included spinal cord (5), mesenteric (40), renal (51), and lower extremity (47). Major morbidity included dialysis need (11), stroke (3), paralysis (2), and 30-day mortality (n = 12, 17.4%). Mean Kaplan-Meier survival was 84.3 months. Although late mortality was associated with age (P < .0001), neither the type nor the number of malperfused vascular beds correlated with vital status at last follow-up (P > .4). Freedom from aortic rupture or open repair at 1, 5, and 8 years was 80.2%, 67.7%, and 54.2%, respectively. CONCLUSION Presentation with acute type B dissection with malperfusion carries a significant risk for both early and late mortality. Percutaneous approaches allow for rapid restoration of end-organ perfusion with acceptable results. These long-term results can serve as comparative data by which to evaluate newer therapies for acute type B dissection with malperfusion, such as thoracic aortic endovascular repair.

A population-based analysis of endovascular versus open thoracic aortic aneurysm repair.

OBJECTIVE The perioperative outcomes of open surgical and endovascular repair of intact thoracic aortic aneurysms (TAAs) during the last 3 months of 2005 were compared using a national administrative database. METHODS The Nationwide Inpatient Sample was used to identify patients undergoing open aneurysm repair (OAR) or endovascular TAA repair (TEVAR) from October 1 to December 31, 2005. Patient demographic data, length of stay, hospital charges, patient disposition, and mortality were examined. Where appropriate, univariate tests of association used the chi(2) test, and multiple logistic regression analysis was used to determine predictors of in-hospital mortality, complications, and discharge status. RESULTS A total of 1030 patients underwent open TAA repair and 267 underwent TEVAR. There was no significant difference in mortality between OAR and TEVAR (adjusted odds ratio [OR], 1.2; 95% confidence interval [CI], 0.73-2.12), although OAR patients were more likely to have cardiac, respiratory, and hemorrhagic complications. Patients undergoing TEVAR were more likely to be discharged to home (adjusted OR, 6.37; 95% CI, 2.93-13.70) and had a decreased length of stay (5.7 days vs 9.9 days; P = .0015). The differences in hospital charges and costs were not significant. CONCLUSION Although further study is warranted, this study of a national sample suggests that endovascular TAA repair is safe in the short-term, associated with fewer cardiac, respiratory, and hemorrhagic complications, and requires a shorter hospital stay.

Aortic expansion after acute type B aortic dissection.

BACKGROUND A considerable number of patients with acute type B aortic dissection (ABAD) treated with medical management alone will exhibit aortic enlargement during follow-up, which could lead to aortic aneurysm and rupture. The purpose of this study was to investigate predictors of aortic expansion among ABAD patients enrolled in the International Registry of Acute Aortic Dissection. METHODS We analyzed 191 ABAD patients treated with medical therapy alone enrolled in the registry between 1996 and 2010, with available descending aortic diameter measurements at admission and during follow-up. The annual aortic expansion rate was calculated for all patients, and multivariate regression analysis was used to investigate factors affecting the expansion rate. RESULTS Aortic expansion was observed in 59% of ABAD patients; mean expansion rate was 1.7±7 mm/y. In multivariate analysis, white race (regression coefficient [RC], 4.6; 95% confidence interval [CI], 1.4 to 7.7) and an initial aortic diameter less than 4.0 cm (RC, 6.3; 95% CI, 4.0 to 8.6) were associated with increased aortic expansion. Female sex (RC, -3.8; 95% CI, -6.1 to -1.4), intramural hematoma (RC, -3.8; 95% CI, -6.5 to -1.1), and use of calcium-channel blockers (RC, -3.8; 95% CI, -6.2 to -1.3) were associated with decreased aortic expansion. CONCLUSIONS White race and a small initial aortic diameter were associated with increased aortic expansion during follow-up, and decreased aortic expansion was observed among women, patients with intramural hematoma, and those on calcium-channel blockers. These data raise the possibility that the use of calcium-channel blockers after ABAD may reduce the rate of aortic expansion, and therefore further investigation is warranted.

A comparative analysis of open and endovascular repair for the ruptured descending thoracic aorta

BACKGROUND Successful repair of the ruptured (non-traumatic) descending thoracic aorta (rTA) remains a formidable clinical challenge. Although effective for rTA, traditional open repair (DTAR) has significant associated morbidity. With expanding indications for thoracic endovascular aortic repair (TEVAR), we describe our experience with TEVAR and DTAR in this high-risk setting to elucidate their evolving roles. METHODS Since the inception of our thoracic aortic endovascular program in 1993, 69 patients underwent DTAR (34) or TEVAR (35) for rTA. Patients underwent TEVAR if they were considered nonoperative candidates because of extensive comorbidities (n = 31; 88.6%) or had extremely favorable anatomy for endovascular repair (eg, mid-descending saccular aneurysm, n = 4). Aortic pathology causing rupture was fusiform aneurysm (18), saccular aneurysm/ulcer (22), and dissection (29). Associated aortobronchial fistulae (12) and aortoesophageal (1) fistulae were also present in 18.8%. Arch repair was needed in 46; total descending repair was needed in 33. Follow-up was 100% complete (mean 37.4 months). RESULTS Mean age was 65.9 years (DTAR 60.3 year vs TEVAR 71.3 years, P = .005). In-hospital or 30-day mortality was seen in 13 patients (TEVAR n = 4; 11.4% vs DTAR n = 9; 26.5%, P = .13). Median length of stay was shorter after TEVAR (8 days vs DTAR 15 days, P = .02). Mean Kaplan-Meier survival was similar between groups (TEVAR 67.4 months vs DTAR 65.0 months, P = .7). By multivariate analysis, independent predictors of a composite outcome of early mortality, stroke, permanent spinal cord ischemia, or need for dialysis or tracheostomy included the presentation with hemodynamic instability (P < .001) and treatment with conventional open repair (P = .02). CONCLUSION An endovascular approach for the ruptured (non-traumatic) descending thoracic aorta reduces early morbidity, mortality, and duration of hospitalization, while providing equivalent late outcomes even in an older group largely considered high risk for open repair. These data support a paradigm shift, with TEVAR emerging as the preferred therapy for all patients presenting with descending aortic rupture.