Searched for: in-biosketch:yes
person:pngc01
Femoral Access for Iliac Branched Endoprosthesis Deployment in Patients with a Prior Bifurcated Aortic Stent Graft [Case Report]
Tadros, Rami O; Power, John R; Wengerter, Sean P; Png, C Y Maximilian; Marin, Michael L; Faries, Peter L; McKinsey, James F
This series describes an innovative technique to deploy iliac branched endoprostheses (IBEs) in patients with preexisting endovascular aneurysm repair (EVAR). It demonstrates an alternative approach that may be preferred when brachial access is anatomically challenging or when access site complications are of concern. We detail a technique that uses transfemoral access to bring IBE device components up and over an infrarenal endograft bifurcation and into proper position. This series suggests that endovascular specialists should consider the advantages and disadvantages of a transfemoral approach when selecting the best method of repairing a patient's iliac artery aneurysm after prior EVAR.
PMID: 30012453
ISSN: 1615-5947
CID: 5507032
Delayed Tibioperoneal Trunk Aneurysm after Atherectomy and Balloon Angioplasty [Case Report]
Png, C Y Maximilian; Lau, Ignatius H; Feldman, Zachary M; Finlay, David J
True infrapopliteal aneurysms occur very rarely; the majority of reported cases are secondary to trauma or infection. We report the development of a tibioperoneal trunk aneurysm 6 months after atherectomy and angioplasty and describe subsequent open surgical repair via a great saphenous vein bypass graft.
PMID: 29772325
ISSN: 1615-5947
CID: 5507012
Bilateral May-Thurner syndrome refractory to iliac aneurysm repair [Case Report]
Png, C Y Maximilian; Nakazawa, Kenneth R; Lau, Ignatius H; Tadros, Rami O; Faries, Peter L; Ting, Windsor
Venous complications of iliac artery aneurysms are rare. We report the case of bilateral iliac aneurysms that resulted in iliac vein outflow obstruction despite endovascular aneurysm repair. In our patient, bilateral iliac vein stenting resulted in symptom resolution.
PMID: 29945821
ISSN: 2213-3348
CID: 5507212
Post-General Anesthesia Ultrasound-Guided Venous Mapping Increases Autogenous Access Placement Rates
Png, C Y Maximilian; Korayem, Adam; Finlay, David J
BACKGROUND:This study investigates the impact of introducing a post-general anesthesia ultrasound (PAUS) mapping on the type of vascular access chosen for hemodialysis in patients without previous accesses. METHODS:Two hundred three of 297 consecutive patients met inclusion criteria and were reviewed. Within-subjects analysis was performed on patients with both an outpatient ultrasound-guided vein mapping and a PAUS using sign tests and Wilcoxon signed rank tests. Furthermore, a between-subjects analysis added patients with only the outpatient vein mapping; demographic and comorbidity data were analyzed using t-tests and chi-squared tests. An ordinal logit regression was run for the type of access placed, while a bivariate logit regression was used to compare rates of autogenous access maturation. RESULTS:One hundred sixty-five (81%) patients received both a standard outpatient vein mapping and a PAUS. At the outpatient vein mapping, 130 (79%) patients had suitable veins for an autogenous access, whereas 35 (21%) patients did not have suitable veins for an autogenous access and were planned for a prosthetic access. During PAUS, all 165 (100%) patients were found to have suitable veins for autogenous access formation (P < 0.001). When comparing specific autogenous access configurations, Wilcoxon signed rank testing showed significantly more preferable access configurations in the PAUS group than the outpatient mapping (P < 0.001); outpatient mapping resulted in 81 (47%) radiocephalic accesses, 10 (6%) radiobasilic accesses, 20 (12%) brachiocephalic accesses, 19 (12%) brachiobasilic accesses, and 35 (21%) prosthetic accesses planned, in contrast to 149 (90%) radiocephalic accesses, 3 (2%) radiobasilic accesses, 10 (6%) brachiocephalic accesses, 3 (2%) brachiobasilic accesses, and 0 prosthetic accesses when the same patients were analyzed using PAUS. With the analysis expanded to include the 38 (19%) patients with only the outpatient vein mapping (without-PAUS), the Wilcoxon-Mann-Whitney test showed no significant differences between the groups in terms of outpatient vein mapping plans (P = 0.10); however, when comparing the PAUS plans to the outpatient vein mapping plans, there was again a significantly increased proportion of preferred access types in the PAUS group compared with the outpatient group (P < 0.001). In the ordinal logit multivariate analysis, the only significant variable was the postanesthesia ultrasound, which positively correlated with more favorable access configurations (coefficient = 2.61, P < 0.001). The bivariate logit regression for autogenous access maturation rates found no significant difference between the without-PAUS group and the PAUS group (P = 0.13). CONCLUSIONS:Introducing a postanesthesia ultrasound mapping to guide vein-finding significantly increases the quality and quantity of suitable veins found, subsequently leading to increased proportions preferred access placement (autogenous versus prosthetic and forearm versus upper extremity).
PMID: 29678651
ISSN: 1615-5947
CID: 5507002
Use of the distal radial artery remnant for autogenous radial-cephalic wrist fistula after radial artery harvest for coronary artery bypass grafting [Case Report]
Lau, Ignatius; Png, C Y M; Trivedi, Parth; Finlay, David
Harvesting of the radial artery is a common technique used to provide conduit for coronary artery bypass graft surgery. We report the case of a patient with exhausted left upper extremity access options, history of left upper extremity dialysis access-associated steal syndrome, and prior right radial artery harvest for coronary artery bypass graft who received an autogenous distal radial artery remnant to cephalic vein wrist fistula.
PMCID:6012982
PMID: 29942886
ISSN: 2468-4287
CID: 5507022
Recurrent Iliofemoral Venous Thrombosis in the Setting of May-Thurner Syndrome as the Presenting Symptom of Behcet's Disease [Case Report]
Lakha, Sameer; Png, Chien Yi Maximilian; Chun, Kevin; Ting, Windsor
BACKGROUND:Vascular manifestations including pulmonary artery aneurysms and venous thrombosis are seen in up to 14% of patients with Behcet's disease. We report a patient who had recurrent deep vein thrombosis (DVT) as the presenting symptom of Behcet's Disease. METHODS:A 19-year-old male who presented with acute iliofemoral DVT, confirmed by intravascular ultrasound (IVUS) and venogram. May-Thurner syndrome was also observed. Repeated catheter-based pharmacomechanical thrombolysis, thrombectomy, and subsequent iliac vein stenting were performed. The patient was then discharged on rivaroxaban and aspirin. RESULTS:Five months later, the patient experienced left calf pain. In the interim, he had been diagnosed with Behcet's disease by a rheumatologist who was consulted due to oral ulcers and skin lesions and accordingly started on prednisone, colchicine, and azathioprine. At this time, IVUS and venogram revealed thrombotic occlusion of the previously placed stent. Tissue plasminogen activator was infused into the stent, and pharmacomechanical thrombectomy restored flow through the left iliac veins. Follow-up laboratory workup revealed that subtherapeutic azathioprine dosing, and after appropriate adjustment, the patient has been asymptomatic for 12 months. CONCLUSIONS:Acute refractory DVT is a possible presenting symptom of Behcet's disease, which may be complicated by May-Thurner syndrome. Such patients should receive therapeutic immunosuppression in addition to anticoagulation.
PMID: 29481922
ISSN: 1615-5947
CID: 5506992
Endovascular Treatment of Dialysis Access-Induced Hand Ischemia Using a Flared Stent-Graft [Case Report]
Png, Chien Yi M; Beckerman, William E; Faries, Peter L; Finlay, David J
PURPOSE/OBJECTIVE:To report an investigation of a purely endovascular procedure to address access-induced hand ischemia in dialysis patients. CASE REPORT/METHODS:Two dialysis patients presented with stage III steal syndrome consisting of severe pain and numbness in their fingers. Preoperative fistulograms distal to the anastomosis showed alternating antegrade and retrograde flow. Under ultrasound guidance, the fistula was accessed and a 4-F micropuncture sheath placed. An angled guidewire was then advanced proximally into the brachial artery. A 6-F short sheath with marker was placed followed by a 4-F straight guide catheter inserted into the proximal brachial artery. A 9-F Flair endovascular stent-graft was advanced over a 0.035-inch stiff angled Glidewire into the fistula just distal to the arterial anastomosis and deployed. Postoperatively, pain and numbness resolved in both patients immediately. Postoperative fistulograms documented antegrade flow. Access flow velocity readings decreased significantly and pulse oximetry readings increased significantly in both patients, who were followed for >6 months with no reported complications. CONCLUSION/CONCLUSIONS:These 2 cases suggest that this endovascular approach to access-induced hand ischemia may be a viable alternative to open/hybrid surgery.
PMID: 28675950
ISSN: 1545-1550
CID: 5506982
An anatomic risk model to screen post endovascular aneurysm repair patients for aneurysm sac enlargement
Png, Chien Yi M; Tadros, Rami O; Beckerman, William E; Han, Daniel K; Tardiff, Melissa L; Torres, Marielle R; Marin, Michael L; Faries, Peter L
BACKGROUND:Follow-up computed tomography angiography (CTA) scans add considerable postimplantation costs to endovascular aneurysm repairs (EVARs) of abdominal aortic aneurysms (AAAs). By building a risk model, we hope to identify patients at low risk for aneurysm sac enlargement to minimize unnecessary CTAs. METHODS:895 consecutive patients who underwent EVAR for AAA were reviewed, of which 556 met inclusion criteria. A Probit model was created for aneurysm sac enlargement, with preoperative aneurysm morphology, patient demographics, and operative details as variables. RESULTS:Our final model included 287 patients and had a sensitivity of 100%, a specificity of 68.9%, and an accuracy of 70.4%. Ninety-nine (35%) of patients were assigned to the high-risk group, whereas 188 (65%) of patients were assigned to the low-risk group. Notably, regarding anatomic variables, our model reported that age, pulmonary comorbidities, aortic neck diameter, iliac artery length, and aneurysms were independent predictors of post-EVAR sac enlargement. With the exception of age, all statistically significant variables were qualitatively supported by prior literature. With regards to secondary outcomes, the high-risk group had significantly higher proportions of AAA-related deaths (5.1% versus 1.1%, P = 0.037) and Type 1 endoleaks (9.1% versus 3.2%, P = 0.033). CONCLUSIONS:Our model is a decent predictor of patients at low risk for post AAA EVAR aneurysm sac enlargement and associated complications. With additional validation and refinement, it could be applied to practices to cut down on the overall need for postimplantation CTA.
PMID: 28095987
ISSN: 1095-8673
CID: 5506962
The Protective Effects of Diabetes Mellitus on Post-EVAR AAA Growth and Reinterventions
Png, Chien Yi M; Tadros, Rami O; Kang, Ming; Beckerman, William E; Tardiff, Melissa L; Vouyouka, Ageliki G; Marin, Michael L; Faries, Peter L
BACKGROUND:This study aims to investigate the effect of diabetes on post-endovascular aneurysm repairs (EVARs) of abdominal aortic aneurysms (AAAs). METHODS:A total of 1,479 consecutive patients who underwent AAA EVAR were reviewed. The cohorts were divided based on their diabetes status and compared. Preoperative demographic and comorbidity data were analyzed using the t-test and chi-squared test, whereas post-EVAR outcomes were analyzed using Probit multivariate model, followed by Kaplan-Meier survival curve and Cox regression. RESULTS:Of our 1,479 patients, 993 met inclusion criteria. One hundred eighty-three were diabetics (18.4%) compared with 810 nondiabetics (81.6%). Coronary artery disease (CAD; diabetics: 70.49%, nondiabetics: 60.76%, P = 0.014) and hypertension (HTN; diabetics: 90.16%, nondiabetics: 79.46%, P = 0.0008) were the only comorbidities analyzed, including follow-up length, which had any significant differences between the diabetic and nondiabetic groups. Probit multivariate analysis using a combined cohort follow-up mean of 51 months showed a significant decrease in aneurysm sac enlargement in diabetic patients (diabetics: 13.11%, nondiabetics: 19.43%, model estimate: 0.3058; 95% confidence interval [CI]: 0.0486-0.5629, Pr > ChiSq = 0.0198) and trended toward significantly fewer reinterventions (diabetics: 23.50%, nondiabetics: 28.41%, model estimate: 0.1990; 95% CI: -0.0262 to 0.4243, Pr > ChiSq = 0.0833). In the Cox regressions, diabetes had a significant protective factor on reinterventions (hazard ratio [HR]: 0.697, Pr > ChiSq = 0.0151), and was trending toward significance for aneurysm sac enlargement (HR: 0.750, Pr > ChiSq = 0.1961). There was no significant difference across diabetic status in any other outcomes, including mortality and endoleak occurrence. CONCLUSIONS:Although a higher proportion of diabetic patients present with HTN and CAD, they have decreased long-term rates of aneurysm sac enlargement after EVAR. As a result, this cohort trends toward a lower need for reintervention after EVAR.
PMID: 28302476
ISSN: 1615-5947
CID: 5506972
Vascular surgeon-hospitalist comanagement improves in-hospital mortality at the expense of increased in-hospital cost
Tadros, Rami O; Tardiff, Melissa L; Faries, Peter L; Stoner, Michael; Png, Chien Yi M; Kaplan, David; Vouyouka, Ageliki G; Marin, Michael L
OBJECTIVE:We have shown that vascular surgeon- hospitalist co management resulted in improved in-hospital mortality rates. We now aim to assess the impact of the hospitalist co management service (HCS) on healthcare cost. METHODS:A total of 1558 patients were divided into three cohorts and compared: 516 in 2012, 525 in 2013, and 517 in 2014. The HCS began in January 2013. Data were standardized for six vascular surgeons that were present 2012-2014. New attendings were excluded. Ten hospitalists participated. Case mix index (CMI), contribution margin, total hospital charges (THCs), length of stay (LOS), actual direct costs (ADCs), and actual variable indirect costs (AVICs) were compared. Analysis of variance with post-hoc tests, t-tests, and linear regressions were performed. RESULTS:THC rose by a mean difference of $14,578.31 between 2012 and 2014 (P < .001) with a significant difference found between all groups during the study period (P = .0004). ADC increased more than AVIC; however, both significantly increased over time (P = .0002 and P = .014, respectively). A mean $3326.63 increase in ADC was observed from 2012 to 2014 (P < .0001). AVIC only increased by an average $392.86 during the study period (P = .01). This increased cost was observed in the context of a higher CMI and longer LOS. CMI increased from 2.25 in 2012 to 2.53 in 2014 (P = .006). LOS increased by a mean 1.02 days between 2012 and 2014 (P = .016), and significantly during the study period overall (P = .018). After adjusting for CMI, LOS increases by only 0.61 days between 2012 and 2014 (P = .07). In a final regression model, THC is independently predicted by comanagement, CMI, and LOS. After adjusting for CMI and LOS, the increase in THC because of comanagement (2012 vs 2014) accounts for only $4073.08 of the total increase (P < .001). During this time, 30-day readmission rates decreased by ∼7% (P = .005), while related 30-day readmission rates decreased by ∼2% (P = .32). Physician contribution margin remained unchanged over the 3-year period (P = .76). The most prevalent diagnosis-related group was consistent across all years. Variation in the principal diagnosis code was observed with the prevalence of circulatory disorders because of type II diabetes replacing atherosclerosis with gangrene as the most prevalent diagnosis in 2013 and 2014 compared with 2012. CONCLUSIONS:In-hospital cost is significantly higher since the start of the HCS. This surge may relate to increased CMI, LOS, and improved coding. This increase in cost may be justified as we have observed sustained reduction in in-hospital mortality and slightly improved readmission rates.
PMID: 27988160
ISSN: 1097-6809
CID: 5506952