Michael S Park

Publications (5)16.68 Total impact

• Article: Early versus delayed carotid endarterectomy in symptomatic patients.

  Suman Annambhotla, Michael S Park, Mark L Keldahl, Mark D Morasch, Heron E Rodriguez, William H Pearce, Melina R Kibbe, Mark K Eskandari
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  ABSTRACT: Delayed carotid endarterectomy (CEA) after a stroke or transient ischemic attack (TIA) is associated with risks of recurrent neurologic symptoms. In an effort to preserve cerebral function, urgent early CEA has been recommended in many circumstances. We analyzed outcomes of different time intervals in early CEA in comparison with delayed treatment. Retrospective chart review from a single university hospital tertiary care center between April 1999 and November 2010 revealed 312 patients who underwent CEA following stroke or TIA. Of these 312 patients, 69 received their CEA within 30 days of symptom onset and 243 received their CEA after 30 days from symptom onset. The early CEA cohort was further stratified according to the timing of surgery: group A (27 patients), within 7 days; group B (17), between 8 and 14 days; group C (12), between 15 and 21 days; and group D (12), between 22 and 30 days. Demographic data as well as 30-day (mortality, stroke, TIA, and myocardial infarction) and long-term (all-cause mortality and stroke) adverse outcome rates were analyzed for each group. These were also analyzed for the entire early CEA cohort and compared against the delayed CEA group. Demographics and comorbid conditions were similar between groups. For 30-day outcomes, there were no deaths, 1 stroke (1.4%), 0 TIAs, and 0 myocardial infarctions in the early CEA cohort; in the delayed CEA cohort, there were 4 (1.6%), 4 (1.6%), 2 (0.8%), and 2 (0.8%) patients with these outcomes, respectively (P > .05 for all comparisons). Over the long term, the early group had one ipsilateral stroke at 17 months and the delayed group had two ipsilateral strokes at 3 and 12 months. For long-term outcomes, there were 16 deaths in the early CEA cohort (21%) and 74 deaths in the delayed CEA cohort (30%, P > .05). Mean follow-up times were 4.5 years in the early CEA cohort and 5.8 years in the delayed CEA cohort. There were no differences in 30-day and long-term adverse outcome rates between the early and delayed CEA cohorts. In symptomatic carotid stenosis patients without evidence of intracerebral hemorrhage, carotid occlusion, or permanent neurologic deficits early carotid endarterectomy can be safely performed and is preferred over delaying operative treatment.
  Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 08/2012; 56(5):1296-302. · 3.52 Impact Factor
• Article: Emergent repair of acute thoracic aortic catastrophes: a comparative analysis.

  Peter A Naughton, Michael S Park, Mark D Morasch, Heron E Rodriguez, Manuel Garcia-Toca, C Edward Wang, Mark K Eskandari
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  ABSTRACT: To provide a contemporary institutional comparative analysis of expedient correction of acute catastrophes of the descending thoracic aorta (ACDTA) by traditional direct thoracic aortic repair (DTAR) or thoracic endovascular aortic repair (TEVAR). Single-center retrospective review (April 2001-January 2010). Academic medical center. One hundred patients with ACDTA treated with either TEVAR (n = 76) or DTAR (n = 24). Indications for repair included ruptured degenerative aneurysm (n = 41), traumatic transection (n = 27), complicated acute type B dissection (n = 20), penetrating ulcer (n = 4), intramural hematoma (n = 3), penetrating injury (n = 3), and embolizing lesion (n = 2). Demographics and 30-day and late outcomes were analyzed using multivariate analysis over a mean follow-up of 33.8 months. Among the 100 patients, mean (SD) age was 58.5 (17.3) years (range, 18-87 years). Demographics and comorbid conditions were similar between the 2 groups, except more patients in the DTAR group had prior aortic surgery (P = .02) and were older (P = .01). Overall 30-day mortality was significantly better among the TEVAR group (8% vs 29%; P = .007). Incidence of postoperative myocardial infarction, acute renal failure, stroke, and paraplegia/paresis was similar between the 2 treatment groups (TEVAR, 5%, 12%, 8%, and 8% vs DTAR, 13%, 13%, 9%, and 13%, respectively). Major respiratory complications were lower in the TEVAR group (16% vs 48%; P < .05). Mean length of hospital stay was also shorter after TEVAR (13.5 vs 16.3 days; P = .30). Independent predictors of patient mortality included age (P = .004) and DTAR (P = .001). Patients presenting with ACDTA are best treated with TEVAR whenever feasible.
  Archives of surgery (Chicago, Ill.: 1960) 03/2012; 147(3):243-9. · 4.32 Impact Factor
• Article: Obesity paradox in amputation risk among nonelderly diabetic men.

  Min-Woong Sohn, Elly Budiman-Mak, Elissa H Oh, Michael S Park, Rodney M Stuck, Neil J Stone, William B Pearce
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  ABSTRACT: The association between BMI and amputation risk is not currently well known. We used data for a cohort of diabetic patients treated in the US Department of Veterans Affairs Healthcare System in 2003. Men aged <65 years at the end of follow-up were examined for their amputation risk and amputation-free survival during the next 5 years (2004-2008). Compared to overweight individuals (BMI 25-29.9 kg/m(2)), the risks of amputation and treatment failure (amputation or death) were higher for patients with BMI <25 kg/m(2) and were lower for those with BMI ≥30 kg/m(2). Individuals with BMI ≥40 kg/m(2) were only half as likely to experience any (hazard ratios (HR) = 0.49; 95% confidence interval (CI), 0.30-0.80) and major amputations (HR = 0.53; 95% CI, 0.39-0.73) during follow-up as overweight individuals. While the amputation risk continued to decrease for higher BMI, amputation-free survival showed a slight upturn at BMI >40 kg/m(2). The association between obesity and amputation risk in our data shows a pattern consistent with "obesity paradox" observed in many health conditions. More research is needed to better understand pathophysiological mechanisms that may explain the paradoxical association between obesity and lower-extremity amputation (LEA) risk.
  Obesity 02/2012; 20(2):460-2. · 4.28 Impact Factor
• Article: A comparative study of the bell-bottom technique vs hypogastric exclusion for the treatment of aneurysmal extension to the iliac bifurcation.

  Peter A Naughton, Michael S Park, Elrasheid A H Kheirelseid, Sean M O'Neill, Heron E Rodriguez, Mark D Morasch, Prakash Madhavan, Mark K Eskandari
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  ABSTRACT: A significant proportion of patients undergoing endovascular aneurysm repair (EVAR) have common iliac artery aneurysms (CIAA). Aneurysmal involvement at the iliac bifurcation potentially undermines long-term durability. Patients with CIAA who underwent EVAR were identified in two teaching hospitals. Bell-bottom technique (BBT; iliac limb ≥20 mm) or internal iliac artery embolization and limb extension to the external iliac artery (IIE + EE) were used. Outcome between these two approaches was compared. We identified 185 patients. Indication for EVAR included asymptomatic abdominal aortic aneurysm (AAA) in 157, symptomatic or ruptured aneurysm in 19, and CIAA in nine. Mean AAA diameter was 59 mm. Among 260 large CIAAs that were treated, BBT was used to treat 166 CIAA limbs, and 94 limbs underwent IIE + EE. Total reintervention rates were 11% for BBT (n = 19) and 19.1% for IIE + EE (n = 18; P = .149). Rates of reintervention for type Ib or III endoleak were 4% for BBT (n = 7) and 4% for IIE + EE (n = 4; P > .99). The difference in limb patency rates was not significant. The 30-day mortality rate was 1%. Median follow-up was 22 months. Complications did not differ significantly between the two groups; however, the combined incidence of perioperative complications and reinterventions was higher in the IIE + EE group (49% vs 22%; P = .002). The combined incidence of perioperative complications and reinterventions is significantly higher with IIE + EE than with BBT; therefore, when feasible, BBT is desirable.
  Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 01/2012; 55(4):956-62. · 3.52 Impact Factor
• Article: Does a contralateral carotid occlusion adversely impact carotid artery stenting outcomes?

  Mark L Keldahl, Michael S Park, Manuel Garcia-Toca, Chih-Hsiung E Wang, Melina R Kibbe, Heron E Rodriguez, Mark D Morasch, Mark K Eskandari
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  ABSTRACT: Carotid artery stenting (CAS) has grown as a possible alternative for the treatment of extracranial cerebrovascular disease in the past decade. A preexisting contralateral carotid artery occlusion has been described as a risk factor for inferior outcomes after carotid endarterectomy, but its impact on CAS outcomes is less understood. A retrospective review of 417 CAS procedures performed between May 2001 and July 2010 at a single center using self-expanding nitinol stents and mechanical embolic protection devices was conducted. Patients were divided into two groups, those with a preexisting contralateral carotid occlusion (group A, n = 39) versus those without a contralateral occlusion (group B, n = 378). Patient demographics and comorbidities as well as 30-day and late death, stroke, and myocardial infarction (MI) rates were analyzed. Mean follow-up was 4 years (range: 0-9.4 years). Overall, mean age of the 314 men and 103 women was 70.5 years. In group A, there were two (5.1%) octogenarians and nine patients (23.1%) with symptomatic disease as compared with group B with 53 (14%) octogenarians and 121 (32%) patients with symptomatic disease. The overall 30-day death, stroke, and MI rates were 0.5%, 1.9%, and 0.7%, respectively. When comparing group A with group B, these results were not significantly different: death (0% vs. 0.5%), stroke (2.6% vs. 1.9%), and MI (0% vs. 0.8%). Long-term outcomes for groups A and B were also not significantly different: death (25.6% vs. 22.2%), stroke (5.3% vs. 3.4%), and MI (15.4% vs. 14%) (p = nonsignificant). A preexisting contralateral carotid artery occlusion does not seem to adversely impact CAS outcomes.
  Annals of Vascular Surgery 09/2011; 26(1):40-5. · 1.03 Impact Factor