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Dive into the research topics where Venkatesh G. Ramaiah is active.

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Featured researches published by Venkatesh G. Ramaiah.


Journal of Endovascular Therapy | 2007

Virtual histology intravascular ultrasound assessment of carotid artery disease: the Carotid Artery Plaque Virtual Histology Evaluation (CAPITAL) study.

Edward B. Diethrich; M. Pauliina Margolis; Donald B. Reid; Allen P. Burke; Venkatesh G. Ramaiah; Julio A. Rodriguez-Lopez; Grayson Wheatley; Dawn Olsen; Renu Virmani

Purpose: To determine the diagnostic accuracy of virtual histology intravascular ultrasound imaging (VH IVUS) of carotid plaque and to assess the feasibility of VH IVUS to identify plaque with embolic potential in patients undergoing carotid artery stenting (CAS). Methods: Thirty patients (17 men; mean age 74±7 years) were entered nonrandomly into a single-center, prospective, 2-arm study following FDA and Institutional Review Board approval. In one arm, 15 patients underwent VH IVUS examination of carotid plaque with a cerebral protection device immediately followed by carotid endarterectomy (CEA). A comparison of “virtual” with true histology was then performed, classifying plaque type by VH IVUS and histopathology in a blinded study. In the second arm, 15 patients undergoing CAS had a preliminary VH IVUS scan performed with cerebral protection. Debris collected from the filter following stenting was examined histologically and compared with the VH IVUS data. Results: The diagnostic accuracy of VH IVUS to agree with true histology in different carotid plaque types was 99.4% in thin-cap fibroatheroma, 96.1% for calcified thin-cap fibroatheroma, 85.9% in fibroatheroma, 85.5% for fibrocalcific, 83.4% in pathological intimal thickening, and 72.4% for calcified fibroatheroma. Filter debris was captured in 2 patients prior to CEA and in 4 patients undergoing CAS for restenosis; VH IVUS classification of plaque composition was consistent with the histological evaluation of filter fragments. Calcified nodules projecting into the carotid artery lumen were associated with a higher incidence of previous neurological symptoms (66.7% versus 33.3%, p<0.05), while patients on aspirin has significantly less necrotic lipid core plaque detected by VH IVUS than patients not taking aspirin (6.4%±4.7% versus 9.7%±2.8%, p<0.05). Conclusion: This study showed a strong correlation between VH IVUS plaque characterization and the true histological examination of the plaque following endarterectomy, particularly in “vulnerable” plaque types. The feasibility study to examine VH IVUS data and the filter debris histology in CAS patients supports a larger prospective study.


Journal of Endovascular Therapy | 2006

Endovenous Ablation of Incompetent Saphenous Veins: A Large Single-Center Experience

Rajagopalan Ravi; Julio A. Rodriguez‐Lopez; Edwina A. Trayler; Deborah A. Barrett; Venkatesh G. Ramaiah; Edward B. Diethrich

Purpose: To evaluate the effectiveness of endovenous treatment of symptomatic varicose veins using the endovenous laser (EVL) or radiofrequency (RF) energy over a >3-year follow-up. Methods: From February 2002 to August 2005, 981 consecutive patients (770 women; mean age 51 years, range 15–90) with symptomatic varicose veins in 1250 lower limbs underwent endovenous ablation of 1149 great saphenous veins (GSV) and 101 small saphenous veins (SSV) under tumescent anesthesia without intravenous sedation or regional anesthesia. There were 990 GSV and 101 SSV procedures using EVL; 159 GSVs were treated with RF energy. An ultrasound evaluation was performed within 2 weeks of the procedure to evaluate occlusion of the vein, wall thickness, and clot extension into the deep venous system. Follow-up from the first 200 procedures in the series included clinical evaluation and duplex ultrasound scanning at 6 and 12 months and annually thereafter. Results: Of the 1149 GSVs treated, 39 (3.4%) recanalizations were seen in 33 of the EVL and 6 of the RF procedures for inadequate treatment as judged by ultrasound. There were 9 (9.0%) failures among the 101 SSVs treated with EVL. Overall, both EVL and RF procedures were well tolerated, with only minor complications. One obese patient with ulcer developed pulmonary embolus on the fourth postoperative day. There were no differences between EVL and RF in efficacy or complications. Follow-up at a mean 3 years (range 30–42 months) in 143 treated limbs showed no neovascularization in the groin. Conclusion: Outcomes with EVL and RF were good, with low complication rates that may be related to the use of local tumescent anesthesia without intravenous sedation.


Journal of Vascular Surgery | 2009

A multicenter clinical trial of endovascular stent graft repair of acute catastrophes of the descending thoracic aorta

Richard P. Cambria; Robert S. Crawford; Jae Sung Cho; Joseph E. Bavaria; Mark A. Farber; W. Anthony Lee; Venkatesh G. Ramaiah; Christopher J. Kwolek

OBJECTIVE Thoracic endovascular aortic repair (TEVAR) is applicable to a spectrum of thoracic aortic pathology with half of the procedures performed world-wide for indications other than degenerative aneurysm of the descending thoracic aorta (DTA). This multicenter, prospective study queried perioperative and one-year results of TEVAR using the commercially available GORE TAG device, in the treatment of acute complicated Type B dissection (cTBD), traumatic aortic tear (TT), and ruptured degenerative aneurysm (RDA) of the DTA. METHODS This prospective, non-randomized, literature controlled study included 59 patients; cTBD, n = 19; RDA, n = 20; TT, n = 20. The primary end-point was the composite of death and total paraplegia in subjects at <or= 30 days post-treatment compared with a cohort from current literature. Secondary end-points included adverse events related to device, procedural and systemic complications, and one-year survival. RESULTS All 59 patients had successful endoprosthesis deployment. Fifteen of 19 (79%) patients in the cTBD group had either rupture or malperfusion syndromes at presentation. Combined 30-day mortality/paraplegia rate was 13.6% (8/59), with seven (11.9%) deaths (cTBD [3], RDA [3] and TT [1]) and 1 (TT, 1.7%) case of paraplegia. The primary end-point for the TEVAR cohort was significantly lower (P = .008) when compared with a composite literature control of 800 patients (combined 30-day mortality/paraplegia of 29.6%). Thirty-day complications of any nature occurred in 48 (81%) patients; 11 (18.6%) were device related, and 43 (73%) experienced one or more systemic adverse events. Six (10%) patients required additional TEVAR implantations and 3 (5%) patients (one in each pathology group) required conversion to open surgery. Seventeen (29%) patients had endoleaks of any kind or degree through 30 days; cTBD (7), TT (2), RDA (8). Nine patients (15.3%) had perioperative strokes with two resultant deaths. During mean follow-up time of 409 +/- 309 days, an additional 12 patients died, one patient required open conversion (cTBD), and two patients had major device related events. Actuarial survival at one year was 66% (range, 52%-77%) for the entire cohort; (cTBD) 79% (range, 53%-92%), (TT) 79% (range, 53%-92%) and (RDA) 37% (range, 16%-59%). On regression analysis, age at treatment (1.05 [range, 1.01-1.09]; P = .008) and chronic obstructive pulmonary disease (COPD) (4.3 [range, 1.3-14.4]; P = .02) were predictive of death at one year. CONCLUSION This study confirmed treatment advantages for TEVAR for thoracic aortic catastrophes when compared with literature-based results of open repair. One-year treatment results indicate a low incidence of graft-related complications. TEVAR is the preferred initial treatment for the DTA catastrophes studied herein.


Journal of Endovascular Therapy | 2006

Midterm Outcomes from the TALON Registry: Treating Peripherals with SilverHawk: Outcomes Collection

Venkatesh G. Ramaiah; Roger S. Gammon; Stefan Kiesz; Joseph Cardenas; John Paul Runyon; Peter S. Fail; Craig M. Walker; David E. Allie; Jack R. Chamberlin; Maurice Solis; Lawrence A. Garcia; David E. Kandzari

Purpose: To determine midterm clinical outcomes among patients with lower extremity peripheral arterial disease who underwent revascularization with catheter-based plaque excision (PE). Methods: Between August 2003 and February 2005, 19 institutions participating in the observational, nonrandomized, multicenter TALON registry enrolled 601 consecutive patients (353 men; mean age 70±11, range 36–98) with 1258 symptomatic lower extremity atherosclerotic lesions (748 limbs) treated by plaque excision with the SilverHawk catheter. Approximately 50% of the patients had diabetes, and nearly one third of the procedures were indicated for Rutherford ischemia category ≥4. Mean lesion lengths above and below the knee, respectively, were 62.5±68.5 mm (interquartile range [IQR], 20.0–80.0) and 33.4±42.7 mm (IQR 15.0–37.5). The primary endpoints of the study were target lesion revascularization (TLR) at 6 and 12 months. Results: The device achieved ≤50% residual diameter stenosis in 94.7% of lesions; procedural success was 97.6%. Nearly half (41.9%) of the procedures involved PE of ≥2 lesions. Nearly three quarters (73.3%) of the lesions did not require adjunctive therapy, and stent placement following PE occurred in only 6.3% of lesions. The 6- and 12-month rates of survival free of TLR were 90% and 80%, respectively. Rates of TLR were similar among patients with diabetes (11%) and without diabetes (9%). In the multivariate analysis, significant predictors of TLR at 6 months were a history of MI or coronary revascularization (HR 5.49, 95% CI 1.87 to 16.10, p=0.0008), multiple (≥2) lesions (HR 1.37, 95% CI 1.11 to 1.70, p=0.0019), and increasing Rutherford category (HR 1.84, 95% CI 1.28 to 2.65, p=0.0003). Lesion length >50 mm was associated with a 2.9-fold increased risk for TLR (HR 2.88, 95% CI 1.18 to 7.01, p=0.012); lesion length >100 mm was associated with a 3.3-fold increase in TLR (HR 3.32, 95% CI 1.15 to 9.56, p=0.016). Conclusion: In patients undergoing revascularization for lower extremity atherosclerotic disease, catheter-based PE achieves favorable procedural success and avoids the need for repeat revascularization at midterm follow-up. These findings support PE as a primary endovascular therapy for patients undergoing lower extremity arterial revascularization.


Journal of Trauma-injury Infection and Critical Care | 2002

Acute traumatic rupture of the thoracic aorta treated with endoluminal stent grafts.

Charles S. Thompson; Julio A. Rodriguez; Venkatesh G. Ramaiah; Leanne DiMugno; Shoaib Shafique; Dawn Olsen; Edward B. Diethrich

BACKGROUND Endovascular technologies provide a new therapeutic option in the treatment for acute traumatic rupture of the thoracic aorta. We report our experience with endoluminal stent graft repair of thoracic aortic ruptures. METHODS Five patients underwent repair of the thoracic aorta with an endoluminal stent graft for acute traumatic rupture. Data from patient history, the procedure, hospital course, and follow-up were analyzed. RESULTS All patient were involved in motor vehicle crashes. The mean Injury Severity Score was 51.8 +/- 6.38. All procedures were technically successful. Mean operating room time was 111 minutes and mean estimated blood loss was 200 mL. There were no cases of postprocedural endoleaks or conversions. There were no procedural complications, paraplegia, or deaths. Average follow-up was 20.2 months. CONCLUSION Five cases of successful endograft repair of thoracic aortic rupture have been demonstrated. This should encourage future studies to determine whether endovascular repair of thoracic aortic ruptures is a safe and feasible alternative to conventional open repair.


Journal of Vascular Surgery | 2008

Aortic remodeling after endografting of thoracoabdominal aortic dissection

Julio A. Rodriguez; Dawn Olsen; Leonardo Aguiar Lucas; Grayson H. Wheatley; Venkatesh G. Ramaiah; Edward B. Diethrich

PURPOSE This study assessed the clinical outcome, morphologic changes, and behavior of acute and chronic type B aortic dissections after endovascular repair and evaluated the extent of dissection and diameter changes in the true (TL), false (FL), and whole lumen (WL) during follow-up. METHODS From May 2000 to September 2006, preprocedural and follow-up computed tomography scans were evaluated in 106 patients. Indices of the TL (TLi) and FL (FLi) were calculated at the proximal (p), middle (m), and distal (d) third of the descending thoracic aorta by dividing the TL or FL diameter by the WL. Analyses were by paired t test and chi2. RESULTS Stent grafts were used to treat 106 patients (mean age, 55 years, 70% men) with acute 59 (55.7%) and chronic 47 (44.3%) lesions. The entry site was successfully covered in 100 patients. The incidences of paraplegia and paresis were 2.8% and 1.0%. Mortality was 7.5% (8 patients), including two intraoperative deaths of contained ruptures. Seven (6.6%) early endoleaks occurred. At a mean follow-up of 15.6 months, TLi improved from 0.45 to 0.88 in the proximal third (p/3), from 0.42 to 0.81 in the middle third (m/3), and from 0.44 to 0.74 in the distal third (d/3), demonstrating expansion of the TL. Two patients had decrease in TL due to endoleak needing reintervention. The FLi decreased from 0.41 to 0.06 in p/3, from 0.44 to 0.10 in the m/3, and from 0.42 to 0.21 in the d/3, indicating FL shrinkage. Changes in the TLi and FLi were statistically significant. The decrease in the WL after repair was statistically significant in the proximal and middle aorta. Fourteen patients (13.2%) had increase in WL; seven required a second intervention. FL thrombosis occurred in 69 (65.1%). During follow-up, 36 (36.9%) patients had no retrograde flow, with complete shrinkage of the FL. The FL completely shrank in 28 patients (26.4%) despite retrograde flow. The FL increased in eight patients (7.5%); five needed reintervention. Thrombosis of FL was statistically significant with acute dissections and when dissection remained above the diaphragm (type IIIA; P = .001 and P = .0133). CONCLUSION Remodeling changes were seen when the entry tear was covered. The fate of the FL was determined by persistent antegrade flow and the level of the retrograde flow. Endografting for thoracic type B dissection was successful and promoted positive aortic remodeling changes.


Journal of Endovascular Therapy | 2006

Procedural and Clinical Outcomes with Catheter-Based Plaque Excision in Critical Limb Ischemia

David E. Kandzari; R. Stefan Kiesz; David E. Allie; Craig M. Walker; Peter S. Fail; Venkatesh G. Ramaiah; Joseph R. Cardenas; Jose Vale; Atul Chopra; Roger S. Gammon

Purpose: To examine the safety and efficacy of catheter-based plaque excision as an alternative therapy to surgery, conventional angioplasty, and/or stenting in high-risk patients with critical limb ischemia (CLI). Methods: Between August 2003 and August 2004, a prospective evaluation was conducted of consecutive patients with CLI (Rutherford category ≥5) who were treated with endovascular plaque excision at 7 institutions. This study enrolled 69 patients (37 women; mean age 70±12 years, range 43–93) with CLI involving 76 limbs. Clinical outcomes were prospectively followed for 6 months. The primary endpoint was major adverse events (death, myocardial infarction, unplanned amputation, or repeat target vessel revascularization) at 30 days. Visible healing of ulcerated tissue, avoidance of any amputation, and performance of less extensive amputation than initially planned were also assessed. Results: Procedural success was achieved in 99% of cases. Major adverse events occurred in 1% of patients at 30 days and 23% at 6 months. The target lesion revascularization rate was 4%, and there were no unplanned limb amputations. Amputation was less extensive than initially planned or avoided altogether in 92% of patients at 30 days and 82% at 6 months. Conclusion: Catheter-based plaque excision is a safe and effective revascularization method for patients with CLI. These findings support further study of this modality as a singular or adjunctive endovascular therapy for limb salvage in CLI.


European Journal of Cardio-Thoracic Surgery | 2008

Retrograde type A dissection after endovascular stenting of the descending thoracic aorta. Is the risk real

Jacques Kpodonu; Ourania Preventza; Venkatesh G. Ramaiah; Hani Shennib; Grayson H. Wheatley; Julio Rodriquez-Lopez; James Williams; Edward B. Diethrich

OBJECTIVE Retrograde type A dissection during or after endoluminal graft repair of the descending thoracic aorta is a potentially lethal complication unique to thoracic endografting. Our aim is to increase its awareness and to review possible etiological factors. METHODS Two hundred and eighty-seven patients with different thoracic aortic pathologies were treated with endovascular prostheses over the last 6 years (February 2000 to March 2006) under a single-site protocol. A retrospective review was conducted to identify any retrograde aortic dissections by both chart and film review. Factors that may have contributed to its formation were also documented. This population was analyzed for the complication of retrograde aortic dissection as well as the factors related to its occurrence. RESULTS Seven patients (2.4%) with a gender distribution of three males and four females experienced a retrograde type A dissection within this sample at a median of 202 days. The mean age was 74 years (range 53-83). Aortic pathologies included aortic dissections (n=6) and thoracic aortic aneurysm (n=1). There were (n=3) 43% retrograde type A dissections identified within the perioperative period. Balloon angioplasty was performed in 71.4% (n=5). Two female patients (28.6%) had this event identified within their initial hospitalization with fatal consequences. Overall mortality was 57% (n=4) with extension of dissection the primary cause of death n=3 and open surgical repair (n=1) after an extension of retrograde dissection. CONCLUSIONS Female gender, use of stent-grafts for dissection and possible aggressive balloon angioplasty may play a role in the cause of retrograde type A dissection. A close surveillance program is recommended when using thoracic endografts outside the recommended device instructions for use.


Journal of Endovascular Therapy | 2004

Endovenous Laser Ablation of the Saphenous Vein for Treatment of Venous Insufficiency and Varicose Veins: Early Results from a Large Single-Center Experience

Paul Perkowski; Rajagopalan Ravi; Ramesh C.N. Gowda; Dawn Olsen; Venkatesh G. Ramaiah; Julio A. Rodriguez‐Lopez; Edward B. Diethrich

Purpose: To report early results of a single-center experience with endovenous laser ablation of the saphenous vein (ELAS). Methods: From February 2002 to January 2003, 165 eligible patients (116 women; mean age 59.1 years, range 27–90) were treated with ELAS for venous insufficiency in 203 lower limbs. All patients were symptomatic, and the majority (62%) had class 4 or higher clinical disease (CEAP classification). Eighteen (8.9%) patients had ulcers. A 940-nm diode laser was used in an office setting under local tumescent anesthesia to deliver 100 to 140 laser applications along the course of the vein. Two weeks of compression bandages and a 1-week course of ibuprofen were prescribed postoperatively. All patients underwent a duplex scan of the target vein at 2 weeks. Results: The great (154, 76%), short 37 (18%), and accessory 12 (6%) saphenous veins were ablated, achieving a 97% clinical success rate. Postoperative complications were few (mild induration and ecchymosis) and well tolerated (no DVT or nerve injury). Of the 6 (3.0%) recanalized target veins, 4 were only partially open and successfully treated with sclerosis. Of the 18 patients with active ulceration, 15 (83%) demonstrated healing after ELAS. In a satisfaction survey of patients more than 1 year after ELAS treatment, 84% of the 31 responders claimed their symptoms had diminished to none or minimal; 97% were mostly or very satisfied with their treatment results. Conclusions: ELAS for symptomatic saphenous vein incompetence and varicose veins has excellent short-term subjective and objective outcomes. This technique appears to be very successful in reducing symptoms, resolving varicose veins, and healing ulcers.


Journal of Vascular Surgery | 2012

Hybrid repair of thoracic aortic lesions for zone 0 and 1 in high-risk patients

Nadia Vallejo; Julio A. Rodriguez‐Lopez; Paniz Heidari; Grayson H. Wheatley; David J. Caparrelli; Venkatesh G. Ramaiah; Edward B. Diethrich

PURPOSE Some patients with aortic arch or descending thoracic aorta pathologies are not suited for open repair because of comorbidities that may increase their risk of procedural complications or death. Endovascular approaches may also be difficult when there are inadequate proximal landing zones in the aortic arch. We report our experience using rerouting techniques with bypass, stenting of the branches, or a combination of both to create a landing area in zones 0 and 1 of the aortic arch. METHODS Since November 2002, thoracic aortic endoluminal grafts were placed in 38 patients in whom the endograft was deployed in zone 0 (n = 27) or zone 1 (n = 11). A retrospective review is included. RESULTS There were 11 women and 27 men with a mean age of 65.4 years (range 38-88). Aortic pathology included 12 Stanford type A dissections, 10 aortic arch aneurysms, 8 Stanford type B dissections, 3 descending thoracic aortic aneurysms, 2 aortobronchial fistulas, 1 innominate artery aneurysm and 2 aortic arch pseudoaneurysms. In zone 0, 21 had thoracic debranching with an ascending bypass, three patients had a remote-inflow and three patients had a chimney-stent with carotid-carotid bypass. In zone 1, five patients had a carotid-carotid bypass, one patient had an aortic to left common carotid artery (LCCA) bypass and five patients had chimney-stent on the LCCA. Fifty-eight percent of the patients were symptomatic and 26% emergent. Three patients required hemodialysis postoperatively (7.9%), 18 patients (47.4%) required prolonged mechanical ventilation for respiratory insufficiency. Paraplegia occurred in one patient (2.7%), and five patients suffered a cerebrovascular accident (13.1%). There were four early type I and two type II endoleaks. Overall 30-day mortality was 23.7%. CONCLUSIONS The hybrid approach for repair of the aortic arch pathologies is feasible in patients unfit for open repair. We present the results of performing different techniques to treat the aortic arch with hybrid repair with antegrade or retrograde inflow, stenting of the branches or a combination of both. Long-term results are unknown, and larger series results and comparative studies are needed to determine safety and efficacy.

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Dawn Olsen

Arizona Heart Institute

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Ourania Preventza

Baylor College of Medicine

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