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Dive into the research topics where Samuel S. Leake is active.

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Featured researches published by Samuel S. Leake.


Journal of Vascular Surgery | 2015

Treatment and outcomes of aortic endograft infection

Matthew R. Smeds; Audra A. Duncan; Michael P. Harlander-Locke; Peter F. Lawrence; Sean P. Lyden; Javariah Fatima; Mark K. Eskandari; Sean P. Steenberge; Tadaki M. Tomita; Mark D. Morasch; Jeffrey Jim; Lewis C. Lyons; Kristofer M. Charlton-Ouw; Harith Mushtaq; Samuel S. Leake; Raghu L. Motaganahalli; Peter R. Nelson; Godfrey Ross Parkerson; Sherene Shalhub; Paul Bove; Gregory Modrall; Victor J. Davila; Samuel R. Money; Nasim Hedayati; Ahmed M. Abou-Zamzam; Christopher J. Abularrage; Catherine M. Wittgen

OBJECTIVE This study examined the medical and surgical management and outcomes of patients with aortic endograft infection after abdominal endovascular aortic repair (EVAR) or thoracic endovascular aortic repair (TEVAR). METHODS Patients diagnosed with infected aortic endografts after EVAR/TEVAR between January 1, 2004, and January 1, 2014, were reviewed using a standardized, multi-institutional database. Demographic, comorbidity, medical management, surgical, and outcomes data were included. RESULTS An aortic endograft infection was diagnosed in 206 patients (EVAR, n = 180; TEVAR, n = 26) at a mean 22 months after implant. Clinical findings at presentation included pain (66%), fever/chills (66%), and aortic fistula (27%). Ultimately, 197 patients underwent surgical management after a mean of 153 days. In situ aortic replacement was performed in 186 patients (90%) using cryopreserved allograft in 54, neoaortoiliac system in 21, prosthetic in 111 (83% soaked in antibiotic), and 11 patients underwent axillary-(bi)femoral bypass. Graft cultures were primarily polymicrobial (35%) and gram-positive (22%). Mean hospital length of stay was 23 days, with perioperative 30-day morbidity of 35% and mortality of 11%. Of the nine patients managed only medically, four of five TEVAR patients died after mean of 56 days and two of four EVAR patients died; both deaths were graft-related (mean follow-up, 4 months). Nineteen replacement grafts were explanted after a mean of 540 days and were most commonly associated with prosthetic graft material not soaked in antibiotic and extra-anatomic bypass. Mean follow-up was 21 months, with life-table survival of 70%, 65%, 61%, 56%, and 51% at 1, 2, 3, 4, and 5 years, respectively. CONCLUSIONS Aortic endograft infection can be eradicated by excision and in situ or extra-anatomic replacement but is often associated with early postoperative morbidity and mortality and occasionally with a need for late removal for reinfection. Prosthetic graft replacement after explanation is associated with higher reinfection and graft-related complications and decreased survival compared with autogenous reconstruction.


Journal of Trauma-injury Infection and Critical Care | 2015

Contemporary management and outcomes of blunt thoracic aortic injury: A multicenter retrospective study

Joseph DuBose; Samuel S. Leake; Megan Brenner; Jason Pasley; Thomas O’Callaghan; Xian Luo-Owen; Marc D. Trust; Jennifer Mooney; Frank Z. Zhao; Ali Azizzadeh

BACKGROUND Blunt thoracic aortic injuries (BTAIs) are composed of a spectrum of lesions ranging from intimal tear to rupture, yet optimal management and ultimate outcome have not been clearly established. METHODS This is a retrospective multicenter study of BTAIs from January 2008 to December 2013. Demographics, diagnosis, treatment, and in-hospital outcomes were analyzed. RESULTS Nine American College of Surgeons–verified Level I trauma centers contributed data from 453 patients with BTAIs. After exclusion of patients expiring before imaging (58) and transfers (13), 382 patients with imaging diagnosis were available for analysis (Grade 1, 94; Grade 2, 68; Grade 3, 192; Grade 4, 28). Hypotension was present on admission in 56 (14.7%). Computed tomographic angiography was used for diagnosis in 94.5%. Nonoperative management (NOM) was selected in 32%, with two in-hospital failures (Grade 1, Grade 4) requiring endovascular salvage (thoracic endovascular aortic repair [TEVAR]). Open repair (OR) was completed in 61 (16%). TEVAR was conducted in 198 (52%), with 41% of these requiring left subclavian artery coverage. Complications of TEVAR included endograft malposition (6, 3.0%), endoleak (5, 2.5%), paralysis (1, 0.5%), and stroke (2, 1.0%). Six TEVAR failures were treated by repeat TEVAR (2) or OR (4). Overall in-hospital mortality was 18.8%, and aortic-related mortality was 6.5% (NOM, 9.8%; OR, 13.1%; TEVAR, 2.5%) (Grade 1, 0%; Grade 2, 2.9%; Grade 3, 5.2%; Grade 4, 46.4%). The majority of aortic-related deaths (18 of 25) occurred before the opportunity for repair. Independent predictors of aortic-related mortality among BTAI patients were higher chest Abbreviated Injury Scale (AIS) score, grade, and Injury Severity Score (ISS); TEVAR was protective (p = 0.03; odds ratio, 0.21; confidence interval, 0.05–0.88). CONCLUSION Failures and aortic-related mortality of NOM following BTAI Society of Vascular Surgery Grade 1 to 3 injuries are rare. TEVAR seems independently protective against aortic-related mortality. Early complications of TEVAR have decreased relative to previous reports. Prospective long-term follow-up data are required to better refine indications for intervention. LEVEL OF EVIDENCE Level IV.


American Journal of Surgery | 2013

Pneumomediastinum: etiology and a guide to diagnosis and treatment

Farzaneh Banki; Anthony L. Estrera; Ryan G. Harrison; Charles C. Miller; Samuel S. Leake; Kyle G. Mitchell; Kamal Khalil; Hazim J. Safi; Larry R. Kaiser

BACKGROUND Pneumomediastinum may be associated with mediastinal organ injury. The aim of this study was to identify predictive factors of mediastinal organ injury in patients with pneumomediastinum to guide diagnosis and treatment. METHODS A retrospective review was conducted including patients aged ≥18 years with Current Procedural Terminology code 518.1 (interstitial emphysema) from 2005-2011. RESULTS There were 279 of 343 patients (81%) with and 64 of 343 (19%) without history of trauma. In the trauma population, 13 patients (5%) were found to have mediastinal organ injuries, 10 (4%) had airway injuries, and 3 (1%) had esophageal injuries. In the nontrauma population, 36 patients (56%) had spontaneous pneumomediastinum, esophageal injuries were seen in 17 (27%), pneumothorax in 9 (14%), and airway injuries in 2 (3%). The predictors of esophageal injury were instrumentation (odds ratio [OR], 45.7; P < .0001), pleural effusion (OR, 10.5; P < .0001), and vomiting (OR, 9.3; P < .0001). Previous instrumentation was the most significant predictor of airway injury (OR, 9.05; P < .02). CONCLUSIONS Mediastinal organ injury in patients with pneumomediastinum is uncommon. Patients presenting with pneumomediastinum without a history of instrumentation, pleural effusion, or vomiting most commonly do not have mediastinal organ injuries.


Circulation | 2015

Outcomes of Patients With Acute Type B (DeBakey III) Aortic Dissection: A 13-Year, Single-Center Experience.

Rana O. Afifi; Harleen K. Sandhu; Samuel S. Leake; Mina L. Boutrous; Varsha Kumar; Ali Azizzadeh; Kristofer M. Charlton-Ouw; Naveed U. Saqib; Tom C. Nguyen; Charles C. Miller; Hazim J. Safi; Anthony L. Estrera

Background— Aortic dissection remains the most common aortic catastrophe. In the endovascular era, the management of acute type B aortic dissection (ATBAD) is undergoing dramatic changes. The aim of this study is to evaluate the long-term outcomes of patients with ATBAD who were treated at our center over a 13-year period. Methods and Results— We reviewed patients with ATBAD between 2001 and 2014, analyzing variables based on status (complicated [c] versus uncomplicated [u]) and treatment modalities. We defined cATBAD as rupture, expansion of diameter on imaging during the admission, persistent pain, or clinical malperfusion leading to a deficit in cerebral, spinal, visceral, renal, or peripheral vascular territories at presentation or during initial hospitalization. Postoperative outcomes were defined as deficits not present before the intervention. Outcomes were compared between the groups by use of Kaplan-Meier and descriptive statistics. We treated 442 patients with ATBAD. Of those 442, 60.6% had uATBAD and were treated medically, and 39.4% had cATBAD, of whom 39.0% were treated medically to 30.0% with open repair, 21.3% with thoracic endovascular aortic repair, and 9.7% with other open peripheral procedures. Intervention-free survival at 1 and 5 years was 84.8% and 62.7% for uATBAD, 61.8% and 44.0% for cATBAD-medical, 69.2% and 47.2% for cATBAD-open, and 68.0% and 42.5% for cATBAD–thoracic endovascular aortic repair, respectively (P=0.001). Overall survival was significantly related primarily to complicated presentation. Conclusions— In our experience, early and late outcomes of ATBAD were dependent on the presence of complications, with cATBAD faring worse. Although uATBAD was associated with favorable early survival, late complications still occurred, mandating radiographic surveillance and open or endovascular interventions. Prospective trials are required to better determine the optimal therapy for uATBAD.


Journal of Vascular Surgery | 2013

Management of limb ischemia in acute proximal aortic dissection

Kristofer M. Charlton-Ouw; Kaji Sritharan; Samuel S. Leake; Harleen K. Sandhu; Charles C. Miller; Ali Azizzadeh; Hazim J. Safi; Anthony L. Estrera

BACKGROUND Management of limb and other malperfusion syndromes is controversial in acute type A aortic dissection. We assessed our hypothesis that urgent proximal aortic repair resolves most cases of limb ischemia without additional peripheral revascularization. METHODS We retrospectively reviewed operative cases of acute type A aortic dissection from 1999 to 2011. Our standard technique involved urgent replacement of the ascending aorta and hemiarch. Persistent limb ischemia after aortic repair was treated by bypass surgery. Comparisons between groups both with and without limb ischemia were made. RESULTS We repaired 335 cases during the study period. Sixty-one patients had limb ischemia (18.2%), of whom 51 were classified with lower limb ischemia (15.2%). All patients with upper limb ischemia survived to discharge without limb loss or death. Only 11 of the 51 patients with lower limb ischemia (21.6%) required peripheral revascularization after aortic repair. There was one case of lower limb loss resulting from delayed recognition of persistent ischemia. Renal dysfunction occurred in 21% of patients with isolated lower limb ischemia and in 31% of patients with uncomplicated dissection (P = .29). In-hospital mortality was 13.7% overall and 8.0% in patients with isolated lower limb ischemia (P = .89). There was no difference in long-term survival between isolated limb ischemia and uncomplicated cases (P = .54). CONCLUSIONS Most cases of limb ischemia resolve after immediate repair of acute type A aortic dissection. There is no difference in renal dysfunction or in-hospital or long-term mortality between patients with isolated limb ischemia and those with nonmalperfusion dissection. If ischemia persists, limb salvage is successful if revascularization is expeditious.


The Annals of Thoracic Surgery | 2015

Is Total Arch Replacement Associated With Worse Outcomes During Repair of Acute Type A Aortic Dissection

Robert D. Rice; Harleen K. Sandhu; Samuel S. Leake; Rana O. Afifi; Ali Azizzadeh; Kristofer M. Charlton-Ouw; Tom C. Nguyen; Charles C. Miller; Hazim J. Safi; Anthony L. Estrera

BACKGROUND As acute type A aortic dissection (ATAAD) remains a challenge, the extent of resection of the transverse arch remains debated during operative repair. The purpose of this study was to compare the outcomes of total arch repair versus ascending/proximal arch repair for ATAAD. METHODS We retrospectively reviewed our aortic database of ATAAD between October 1999 and December 2014. Patients were divided into two groups: total arch repair versus proximal arch repair (hemiarch). Indications for arch replacement during ATAAD include aneurysm greater than 5 cm, complex arch tear, and arch rupture. Inhospital and long-term outcomes were compared between the two groups using univariate analysis and multiple logistic regression analysis. Survival was analyzed using Kaplan-Meier and log rank statistics, and assessment of risk factors for survival was conducted by Cox proportional hazards regression analysis. RESULTS During the study period, we performed 489 repairs of ATAAD, 49 patients (10%) with total arch replacement and 440 patients (90%) with proximal arch replacement. Patients with total arch repair were older (62.4 ± 13.4 years versus 57.9 ± 14.8 years, p = 0.046) and had significantly increased retrograde aortic dissection, circulatory arrest, and retrograde cerebral perfusion times. The incidences of early mortality, stroke, and need for renal dialysis between the total arch and proximal arch group were not significantly different: 20.4% (10 of 49) versus 12.9% (57 of 440), 8.2% (4 of 49) versus 10.5% (46 of 440), and 27% (13 of 49) versus 17.6% (76 of 432), respectively. Late survival did not demonstrate a difference between groups. CONCLUSIONS Acute type A aortic dissection remains a challenge associated with significant mortality and morbidity. When compared with a less aggressive resection, total arch replacement performed in an individualized fashion can be associated with acceptable early and late outcomes for ATAAD and was not associated with worse outcomes.


Journal of Vascular Surgery | 2013

Management of common carotid artery dissection due to extension from acute type A (DeBakey I) aortic dissection

Kristofer M. Charlton-Ouw; Ali Azizzadeh; Harleen K. Sandhu; Ali Sawal; Samuel S. Leake; Charles C. Miller; Anthony L. Estrera; Hazim J. Safi

BACKGROUND Acute type A aortic dissection can extend into arch vessels, including the common carotid arteries. Although several reports describe concomitant endovascular repair of common carotid artery dissection (CCAD) during open ascending aortic repair, the criteria for repair, natural history, and risk of stroke are unclear. We examine the literature and our experience with nonoperative management of CCAD after acute aortic dissection repair to determine the risk of stroke and the need for carotid revascularization. METHODS We queried our cases of type A aortic dissection over a 10-year period from January 2002 to December 2011. Imaging was reviewed to determine the presence of CCAD and degree of true-lumen stenosis. Analysis was performed to determine risk of stroke and survival on initial presentation and during follow-up. Survival functions between excluded groups and those with and without CCAD were compared using log-rank statistics. RESULTS We repaired 288 cases of acute type A aortic dissection during the study period. Adequate carotid imaging was available in 179 patients and comprised the study group. We identified 43 cases with CCAD (group A, 24.0%) and 136 cases without it (group B, 76.0%). History of previous stroke was not a risk factor for new stroke in either group (P = .517). Bilateral CCAD occurred in 16 cases (37.2%). Stroke on initial presentation was more common in group A (18.6%) than in group B (8.1%; odds ratio, 2.6; 95% confidence interval, 0.97-6.95; P = .051). Degree of stenosis or false-lumen thrombosis did not affect rate of stroke on presentation. The degree of postoperative true-lumen stenosis ranged from 0% (resolution) to 90%. No patient with CCAD had stroke or required carotid revascularization after discharge on follow-up. The 5-year, stroke-free survival rates in groups A and B were 69.7% and 73.6% (P = .820), respectively. CONCLUSIONS CCAD, due to extension from aortic arch dissection, has a low risk of subsequent stroke after the initial event. Based on current data, there is little evidence to suggest that aortic origin CCAD requires repair in the absence of recurrent symptoms, regardless of the degree of stenosis or false-lumen patency. Recommended optimal medical therapy includes either aspirin or anticoagulation for 6 months after initial presentation. Additional longitudinal studies are needed.


Journal of Vascular Surgery | 2015

Outcome comparison between open and endovascular management of axillosubclavian arterial injuries.

Bernardino C. Branco; Mina L. Boutrous; Joseph DuBose; Samuel S. Leake; Kristopher Charlton-Ouw; Peter Rhee; Joseph L. Mills; Ali Azizzadeh

BACKGROUND Endovascular repair (ER) of axillosubclavian arterial injuries is a minimally invasive alternative to open repair (OR). The purpose of this study was to compare the outcomes of ER vs OR. METHODS A retrospective study was performed of patients who sustained axillosubclavian arterial injuries admitted to two high-volume academic trauma centers between 2003 and 2013. Patients undergoing ER and OR were matched according to 25 different demographic and clinical variables in a 1:3 ratio using propensity scores. The primary outcome was in-hospital mortality. Secondary outcomes were complications and length of stay. RESULTS Among 153 patients (79.7% male; mean age, 32.7 ± 15.9 years) who sustained axillosubclavian arterial injuries, 18 (11.8%) underwent ER and 135 (88.2%) had OR. Matched cases (ER, n = 18) and controls (OR, n = 54) had similar demographic and clinical data, such as age, gender, admission systolic blood pressure and Glasgow Coma Scale score, body Abbreviated Injury Scale scores, Injury Severity Score, and transfusion requirements. Patients undergoing ER had significantly lower in-hospital mortality compared with patients undergoing OR (5.6% vs 27.8%; P = .040; odds ratio, 0.7; 95% confidence interval, 0.6-0.9). Similarly, patients undergoing ER had substantially lower rates of surgical site infections and a trend toward lower rates of sepsis. Outpatient follow-up was available in 88.2% (n = 15) of the patients at a median time of 8 months (1-30 months). Two ER patients required open reintervention for stent-related complications (one for a type Ia endoleak and another for stent thrombosis). CONCLUSIONS In our experience with axillosubclavian arterial injuries, ER was associated with improved mortality and lower complication rates. Patient follow-up demonstrates an acceptable reintervention rate after ER. Further multicenter prospective evaluation is warranted to determine long-term outcomes.


Journal of Vascular Surgery | 2014

Reinfection after resection and revascularization of infected infrarenal abdominal aortic grafts

Kristofer M. Charlton-Ouw; Harleen K. Sandhu; Guanmengqian Huang; Samuel S. Leake; Charles C. Miller; Anthony L. Estrera; Ali Azizzadeh; Hazim J. Safi

OBJECTIVE Despite advances in perioperative care, long-term and amputation-free survival rates are poor after resection of infected abdominal aortic grafts. We reviewed our cases to determine the rate of reinfection and risk factors for mortality and limb loss. METHODS We reviewed cases with infrarenal aortic graft infection from 1999 to 2013. Cases requiring graft excision were included for analysis. Thoracic and thoracoabdominal aortic grafts were excluded. Reconstruction types included both extra-anatomic and in situ grafts. Patient comorbidities, surgical outcomes, and known reinfection rates were assessed. Univariate and Kaplan-Meier analysis were performed. RESULTS Twenty-eight patients had resection of infected infrarenal abdominal aortic grafts during the study period. Most patients (26/28; 93%) had infected aortoiliac or aortofemoral prosthetic bypass grafts, but two of 28 patients had infected endovascular aortoiliac stent grafts. The median age was 69 years (range, 46-86 years), with 68% men and 32% women. Aortoenteric fistulae or graft-enteric erosions were noted in 12 of 28 (43%) patients at operation. There were 79% of patients who had in situ reconstruction, including 4 (14%) with polyester, 1 (4%) with polytetrafluoroethylene, 3 (11%) with cadaveric homograft, 3 (11%) with composite grafts, and 11 (39%) with native femoropopliteal vein grafts. Five (18%) patients had extra-anatomic bypass and one had excision without revascularization. In-hospital mortality after initial graft excision and revascularization occurred in two (7%) patients. Seven (25%) patients had evidence of reinfection after a median of 20 months, of whom five underwent reintervention with two additional in-hospital deaths. All in-hospital deaths occurred in patients with graft-enteric contamination. Overall limb salvage and survival at a mean follow-up of 2.5 years were 82% and 46%, respectively, and did not differ among revascularization types (P = .85 and .74). One-year amputation-free survival was 47% overall. Three patients with native femoropopliteal vein graft repair required amputation in follow-up. Diabetes was the only observed risk factor for amputation (P = .05). Risks for mortality included history of cerebrovascular disease (P = .05) and shock on presentation (P = .04). No other comorbid condition, type of revascularization, or perioperative complication was associated with limb loss or mortality on univariate analysis. CONCLUSIONS Revascularization after excision of infected abdominal aortic grafts can be done with acceptable in-hospital morbidity and mortality. Reinfection is problematic, regardless of revascularization conduit, and is associated with limb loss and death. New and aggressive local anti-infective strategies are warranted.


Journal of Vascular Surgery | 2015

Open repair of adult aortic coarctation mostly by a resection and graft replacement technique

Kristofer M. Charlton-Ouw; Maria E. Codreanu; Samuel S. Leake; Harleen K. Sandhu; Daniel Calderon; Ali Azizzadeh; Anthony L. Estrera; Hazim J. Safi

BACKGROUND We report on our experience with treatment of adults requiring de novo or redo open aortic coarctation repair mostly by a resection and interposition graft technique. METHODS We retrospectively reviewed all patients older than 16 years requiring open repair of aortic coarctation. Indications for repair, operative details, and outcomes were analyzed. RESULTS Between 1996 and 2011, we treated 29 adult aortic coarctation patients with open repair. The mean age was 42 years (range, 17-69 years), and there were 15 men. Nine patients had previous repair with recurrence; the remaining 20 had native coarctation. Thoracic aortic aneurysms were present in 22 patients (76%), ranging in size from 3.0 to 9.6 cm (mean, 4.8 cm). Four patients had intercostal artery aneurysms (range, 1.0-2.5 cm), four had left subclavian artery aneurysms, and four had ascending/arch aneurysms. The most common repair was resection of aortic coarctation with interposition graft replacement (93%). Two patients without aneurysm had bypasses from the proximal descending thoracic aorta to the infrarenal aorta without aortic resection. There was no in-hospital mortality, stroke, or paraplegia. Long-term survival was 89% during a median follow-up of 81 months (interquartile range, 47-118 months), with no patient requiring reoperation on the repaired segment. CONCLUSIONS Open repair of native and recurrent adult aortic coarctation has acceptable morbidity and low mortality. Especially in patients with concomitant aneurysm, resection with interposition graft replacement provides a safe and durable repair option.

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Ali Azizzadeh

University of Texas Health Science Center at Houston

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Hazim J. Safi

University of Texas Health Science Center at Houston

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Harleen K. Sandhu

University of Texas Health Science Center at Houston

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Anthony L. Estrera

University of Texas Health Science Center at Houston

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Charles C. Miller

University of Texas Health Science Center at Houston

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Rana O. Afifi

University of Texas Health Science Center at Houston

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Tom C. Nguyen

University of Texas Health Science Center at Houston

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Joseph DuBose

University of California

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Alexa Perlick

University of Texas Health Science Center at Houston

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