Experiences with ascending aortic endografts using FDA IDE approved devices. What has been done, what lesions can be treated and what challenges remain.

Thoracic endovascular aortic repair (TEVAR) has become an attractive treatment option for thoracic aortic disease. New devices and advanced image-guided procedures are continuously expanding the indications. With improving device technology, diverse stent-graft availability, and imaging modalities, TEVAR has become safer and holds promising potential to expand treatment options, especially for ascending aorta and aortic arch pathology. This article focuses on current evolving endovascular solutions for thoracic ascending aortic diseases and starts with an overview of historical TEVAR landmarks, followed by indications for TEVAR, and concludes with present day challenges.

Experience with early TEVAR treatment of uncomplicated type B aortic dissection.

The current paradigm for the treatment of chronic type B aortic dissection involves primarily medical treatment. The patients are then followed for sequelae like progressive dissection or aneurysmal degeneration, selecting this subgroup for further intervention. The European Collaborator Registry, the Talent Thoracic Retrospective Registry, and several meta-analysis showed that the uncomplicated type B dissection patients who underwent thoracic endovascular aortic repair (TEVAR) outperformed their counterpart in the complicated group. The INSTEAD trial, the first randomized trial to examine whether TEVAR is better than medical management in the chronic stable dissection patients, showed no benefit early on although mid-term data might show some benefit. Clearly more randomized controlled trials are necessary to create a paradigm shift. In the United States, the FDA approved TEVAR devices are for the descending thoracic aortic aneurysm and transection only. The use of these devices for dissection is off-label or for investigation only. As future study might broaden the use of TEVAR for the chronic dissection patients, the use of TEVAR in hybrid surgery and in the ascending aorta is also broadening the indication for this technology. With two decades of innovation behind, TEVAR will continue to evolve and innovate in the years ahead.

Concomitant dual intravascular and subcutaneous microsurgical implantation of xenograft tissue in a rodent model for evaluation of structural degeneration.

INTRODUCTION: An economical animal model to study xenograft tissue degeneration and calcification and the durability of biological vascular patch material and bioprosthetic valve leaflets is desirable. OBJECTIVE: A cost-effective model to analyze xenograft degeneration, calcification, immunologic reaction, and anticalcification treatment was developed. Furthermore, a technique for implant into the vascular lumen of the abdominal aorta in rats is presented. METHODS: Twelve Lewis rats were used as recipients. The microsurgical procedure was performed using a high-definition optical system. Anesthesia was induced and maintained with isoflurane inhalation. The suprarenal and infrarenal portion of the abdominal aorta was isolated, the abdominal aorta was cross-clamped, and a 4-mm square portion of the abdominal aorta was removed. Subsequently, a complementary-sized piece of porcine or bovine glutaraldehyde-fixed bioprosthetic valve leaflet tissue was sutured as a patch in the abdominal aorta. RESULTS: The mean operating time was 45 ± 10 minutes and the mean ischemic time was 25 ± 5 minutes. Early and 3-month survivals were 100%. One rat had intraoperative bleeding. No paralysis or thrombosis was observed. CONCLUSION: Feasibility and reproducibility of removing a portion of the abdominal aorta and replacing it with a patch of xenograft tissue was demonstrated in a rodent model with 100% survival at 3 months. Concomitant dual intravascular and subcutaneous microsurgical implantation of xenograft tissue in a small-animal (rat) model is a cost-effective approach for investigation of xenograft tissue degeneration.

Management of acute type B aortic dissections and acute limb ischemia.

AIM: The aim of this study was to review the management of acute type B aortic dissection (TBAD) with acute limb ischemia. A search using the "Pubmed" resulted in 254 records by combining the Medical Subject Heading keywords (listed separately). The articles were assessed for their validity, correct pathology and patient cohort. Inclusion criteria included all patients with complicated acute TBAD who were candidates for open of thoracic endovascular aortic repair (TEVAR). The exclusion criteria included type A, asymptomatic acute or chronic TBAD, penetrating ulcer or intramural hematoma. TBAD with limb ischemia has a poor prognosis if not diagnosed, triaged and treated promptly. Clinical presentation and diagnostic strategy as well as various imaging are reviewed. Early mortality rate for complicated acute TBAD (with malperfusion to lower extremity) is 12%. The management has moved from open operation to primary TEVAR. In cases with anatomic obstruction, open surgical techniques such as femoral-femoral bypass, axillo-femoral bypass or surgical fenestration can be successful in relief of malperfusion to the affected limb. One-year-survival rates are 85%. A complete to partial reverse aortic remodeling occurred in 78% of survivors of acute TBAD, if primary TEVAR is applied. Acute TBAD with limb ischemia remains a clinical challenge that requires prompt diagnosis and treatment. TEVAR of acute TBAD is associated with relatively low morbidity and mortality, and is more often used as primary approach for patients with limb ischemia. The outcomes with TEVAR compare favorably to the open repair, and initiate reverse aortic remodeling in majority of the survivors.

Effect of the ordered interfacial water layer in protein complex formation: A nonlocal electrostatic approach.

Using a nonlocal electrostatic approach that incorporates the short-range structure of the contacting media, we evaluated the electrostatic contribution to the energy of the complex formation of two model proteins. In this study, we have demonstrated that the existence of an ordered interfacial water layer at the protein-solvent interface reduces the charging energy of the proteins in the aqueous solvent, and consequently increases the electrostatic contribution to the protein binding (change in free energy upon the complex formation of two proteins). This is in contrast with the finding of the continuum electrostatic model, which suggests that electrostatic interactions are not strong enough to compensate for the unfavorable desolvation effects.

The incidence of carcinoma in cytologically benign thyroid cysts.

BACKGROUND: The management of cytologically benign thyroid cysts is controversial. Treatment options include observation, chemical sclerosis, and surgery. This study was undertaken to determine the incidence of carcinoma in cytologically benign thyroid cysts that recur after complete aspiration and to determine the indications for surgery in these patients. METHODS: The medical records of 1189 consecutive patients undergoing thyroid surgery between July 1995 and November 2000 were reviewed. In 34 patients the indication for surgery was a thyroid cyst with benign cytologic findings that refilled at least once after complete aspiration. These patients were selected for further study. RESULTS: The 26 women and 8 men had a median age of 42 years. Fine-needle aspiration cytology was consistent with a benign cyst in all these cases. Final pathologic findings revealed the nodule to be a papillary carcinoma in 4 patients (12%). In another 4 patients (12%) an incidental microscopic papillary carcinoma, separate from the cyst, was identified on final pathologic findings. In all 4 patients with papillary carcinoma the cyst size was greater than 3 cm (range, 3.4 to 5.0 cm). CONCLUSIONS: The incidence of malignancy in cytologically benign thyroid cysts that recur after aspiration is high enough to warrant surgical excision, especially if the cyst is greater than 3 cm in size.

Early and intermediate results of left ventricular reduction surgery.

OBJECTIVE: Left ventricular reduction surgery is a new surgical option for treatment of end-stage cardiac dysfunction, and little is known about hemodynamics and outcome in the European heart failure population. We present our early results with this operation. METHODS: From January 1995 to September 1997, 30 patients (25 men, 5 women; mean age 61.2 years) underwent partial left ventriculectomy. The underlying disease was ischemic in 18 patients and idiopathic dilated cardiomyopathy in 12 patients. Preoperatively 23 patients were in New York Heart Association functional class IV and 7 were in class III. Mean cardiac index, stroke index and ejection fraction were 1.8 +/- 0.3 l/m2 per min, 23.5 +/- 5.1 ml/m2 and 19.3% +/- 6.8%, respectively. Associated procedures were coronary bypass in 18 patients, mitral valvuloplasty in one, aortic or mitral valve replacement in three, dynamic cardiomyoplasty in two, and left ventricular assist device implantation in 1. RESULTS: There were two early deaths: one from bleeding and one from anticoagulant-related cerebral hemorrhage. Regarding late deaths, one patient died from pneumonia 3 months after the operation and two died from dysrhythmia 4 and 17 months postoperatively. The estimated 1-year survival rate calculated by the Kaplan-Meier log-rank method was 85%. Mean cardiac index, stroke index, and ejection fraction rose significantly (P = 0.0001) to 2.9 +/- 0.51/m2 per min, 36.9 +/- 6.2 ml/m2 and 37.8% +/- 9.2%, respectively. Currently 26 patients are in New York Heart Association functional class I or II. CONCLUSIONS: Left ventricular reduction surgery improves objective and subjective parameters of cardiac performance significantly in early and intermediate follow-up. Randomized studies and carefully documented long-term results seem to be necessary to define the role of left ventricular reduction surgery.

Results after partial left ventriculectomy in a European heart failure population.

BACKGROUND: Forty-nine consecutive patients undergoing partial left ventriculectomy (Batista) surgery between January 1995 and June 1998 were studied. METHODS: Patient ages ranged from 12 to 85 years, and all patients were in New York Heart Association functional Class III or IV. Thirty-three patients had ischemic cardiomyopathy, and 16 had idiopathic myopathy. Inclusion criteria were left ventricular end diastolic volume index of > 150 mL/m2, left ventricular ejection fraction of < 20%, or left ventricular end-diastolic diameter of > 70 mm. Sixteen patients were transplant candidates. Partial left ventriculectomy and mitral valve repair by means of a Cosgrove annuloplasty ring plus the Alfieri repair constituted only part of the complex cardiac reconstruction in 38 patients. RESULTS: Five patients died early and five patients died late between 3 and 30 months postoperatively. The actuarial 1-year survival rate was 81%. Twenty-seven patients with coronary artery disease underwent one to five bypass grafts when appropriate. In addition, three patients received aortic valve replacement, four received tricuspid valve repair, two received mitral valve replacement, and two underwent dynamic cardiomyoplasty. Left ventricular (LV) diameter could be reduced from a preoperative mean of 71 to 56 mm postoperatively. LV ejection fraction increased to 36% postoperatively. Ninety percent of patients are in New York Heart Association functional Class I or II. CONCLUSIONS: Patients with end-stage idiopathic or ischemic cardiomyopathies can be improved considerably with partial left ventriculectomy. Any cardiac comorbidity should be repaired simultaneously.

Cerebral spinal fluid drainage and distal aortic perfusion decrease the incidence of neurological deficit: the results of 343 descending and thoracoabdominal aortic aneurysm repairs.

OBJECTIVE: We reviewed our experience of 343 descending and thoracoabdominal aortic aneurysm repairs to determine the impact of the adjuncts distal aortic perfusion and cerebral spinal fluid drainage on neurological deficit and death. MATERIALS AND METHODS: Between January 1991 and March 1996, 104 (30%) patients were operated for thoracoabdominal aortic aneurysm type I, 118 (34%) for type II, 68 (20%) for type III or type IV, and 53 (15%) for descending thoracic type. Before September 1992, simple cross-clamp was used for 94 (27%) patients. After September 1992, adjuncts were used for 186 (54%) patients. RESULTS: Overall neurological deficit was 33/343 (10%). Neurological deficit for simple cross-clamp patients compared to adjunct patients was 15/94 (16%) vs. 12/186 (7%) (O.R. 0.36, p < 0.01). For types I and II the incidence was 11/52 (21%) vs. 12/141 (9%) (O.R. 0.35, p < 0.02) and for type II, nine out of 22 (41%) vs. 11/85 (13%) (O.R. 0.21, p < 0.003). Overall 30-day mortality was 43/343 (13%), including patients presenting with rupture. Excluding these patients, overall 30-day mortality was 33/322 (10%). CONCLUSION: Cerebral spinal fluid drainage and distal aortic perfusion decreased the incidence of neurological deficit and were particularly effective for patients at highest risk with type II thoracoabdominal aortic aneurysm.