I-Hui Wu

Analysis and results of prolonged resuscitation in cardiac arrest patients rescued by extracorporeal membrane oxygenation

OBJECTIVES We conducted this study to determine the result of prolonged cardiopulmonary resuscitation (CPR) with extracorporeal membrane oxygenation (ECMO) and the predictive factors for hospital discharge and ECMO weaning. BACKGROUND Prolonged CPR carries considerable associated mortality and morbidity. As yet, ECMO for prolonged CPR has no definite results. Only small groups of patients and no detailed analysis have been reported. METHODS Candidates for ECMO resuscitation were patients in cardiac arrest receiving CPR >10 min without return of spontaneous circulation and no absolute contraindication. Venoarterial ECMO was set up during CPR. We reviewed the data of 57 prolonged CPR patients who received ECMO during CPR over a six-year period. RESULTS The mean duration of CPR was 47.6 +/- 13.4 min and that of ECMO was 96.1 +/- 87.9 h. The rate of weaning was 66.7%, and the survival rate was 31.6%. Multiple-organ failure was the major reason for mortality, despite successful weaning. Among survivors, long-term follow-up revealed 88.9% survival, and only 5.6% had a severe neurologic deficit. The results indicate that a shorter CPR duration, postcardiotomy arrest, myocardial indicators, a hepatic indicator, and lactic acid are significantly correlated with both weaning and survival, whereas late damage (level on the third or seventh day of reperfusion) rather than initial damage (level on the first day) was more predictive of the results. CONCLUSIONS Prolonged CPR rescue by ECMO provides an acceptable survival rate and outcome in survivors. Our results of the selected cases encourage further investigations of the wider application of ECMO in CPR.

Improved outcome of extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest--a comparison with that for extracorporeal rescue for in-hospital cardiac arrest.

PURPOSE The aim was to investigate the effects of extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest (OHCA) and compare the results with those of in-hospital cardiac arrest (IHCA). METHODS We analyzed our extracorporeal membrane oxygenation (ECMO) results for patients who received ECPR for OHCA or IHCA in the last 5 years. Pre-arrest, resuscitation, and post-resuscitative data were evaluated. RESULTS In the last 5 years, ECPR was used 230 times for OHCA (n=31) and IHCA (n=199). The basic demographic data showed significant differences in age, cardiomyopathy, and location of the initial CPR. Duration of ischemia was shorter in the IHCA group (44.4±24.7 min vs. 67.5±30.6 min, p<0.05). About 50% of each group underwent a further intervention to treat the underlying etiology. ECMO was maintained for a shorter duration in the OHCA patients (61±48 h vs. 94±122 h, p<0.05). Survival to discharge was similar in the two groups (38.7% for OHCA vs. 31.2% for IHCA, p>0.05), as was the favorable outcome rate (25.5% for OHCA vs. 25.1% for IHCA, p>0.05). Survival was acceptable (about 33%) in both groups when the duration of ischemia was no longer than 75 min. CONCLUSIONS In addition to having a beneficial effect in IHCA, ECPR can lead to survival and a positive neurological outcome in selected OHCA patients after prolonged resuscitation. Our results suggest that further investigation of the use of ECMO in OHCA is warranted.

Selective medical treatment of infected aneurysms of the aorta in high risk patients

BACKGROUND Infected aneurysm of the aorta is almost always fatal without undergoing aortic resection. Medical treatment was attempted selectively in patients who were considered too high risk for surgery. We review our experience with 22 patients treated without undergoing aortic resection over 12 years. METHODS Retrospective chart review. RESULTS Between 1995 and 2007, 22 cases of infected aortic aneurysms treated without undergoing aortic resection during the first admission were included. There were 17 men with a median age of 76 years (range, 35 to 88 years). Of 18 pathogens isolated, the most common responsible microorganism was nontyphoid Salmonella in 11 followed by Staphylococcus aureus in five. The site of infection was thoracic in eight and abdominal in 14. The hospital mortality rate was 50%, and the aneurysm-related mortality rate after long-term follow-up was 59%. The event-free survival rate at one year was 32%. Of 11 patients with Salmonella infection, eight patients have lived beyond 30 days and six were event-free after one year. Of 11 patients with non-Salmonella, four patients have lived beyond 30 days and only one was event-free after one year. The overall aneurysm-related mortality rate was 36% in Salmonella infected patients and 82% in non-Salmonella infected patients. CONCLUSION Clinical results of medical treatment using current antibiotics in patients with infected aortic aneurysm were poor. Traditional surgical excision of infected aortic aneurysms with revascularization remains the gold standard and should be attempted except in high risk patients.

Risk Factor Screening Scale to Optimize Treatment for Potential Heart Transplant Candidates under Extracorporeal Membrane Oxygenation

We developed a risk factor‐scaling score (RFSS) to select which patients supported by extracorporeal membrane oxygenation (ECMO) were suitable for ventricular assist device (VAD) implantation or heart transplantation (HTx). A total of 78 patients supported with ECMO for more than 48 h due to cardiac origin were included in this study. Patients were categorized into two groups based on the outcomes: the poor outcome group (n = 33) consisted of for those who later died or were later excluded from VAD or HTx; the favorable outcome group (n = 45) consisted of those who were weaned off ECMO finally and survived or were deemed suitable candidates for VAD or HTx. Seven risk factors were significant according to univariate analyses. Based on the regression coefficients of multivariate analysis, the RFSS was developed: (lung dysfunction × 7) + (systemic infection × 3) + (peak lactate > 3 mmole/L × 3) + (kidney dysfunction × 2) + (creatine kinase > 10 000 U/L × 1). Patients with an RFSS of 7 or more were be allocated to the poor outcome group. The RFSS was validated by another group of 30 patients with good correlation. The RFSS provides a way to predict which ECMO‐supported patients are suitable candidates for VAD implantation or HTx.

The Significance of Endograft Geometry on the Incidence of Intraprosthetic Thrombus Deposits after Abdominal Endovascular Grafting

OBJECTIVES To examine the incidence and risk factors of intraprosthetic thrombotic deposits in abdominal aortic endografts. METHODS The clinical records of 51 patients (44 males; mean age 76.3 years, range: 63-90 years) with abdominal aortic aneurysm treated with transfemoral implantation of bifurcated stent graft between the years 2002 and 2008 were retrospectively reviewed. Patients underwent three-phase helical computed tomographic (CT) examinations at 1-, 3-, 6- and 12-month intervals and then annually. The formation of intraprosthetic thrombus associated with use of anti-platelet, preoperative mural thrombus in the aneurysm, ratio of cross-sectional area between the mainbody and bilateral limb grafts and length of mainbody were evaluated. RESULTS Over a 10-month mean follow-up, intraluminal deposits of thrombotic material were observed in eight of 51 patients (15.6%, 95% confidence interval: 8.2-28). The first signs of thrombus formation occurred on average 9.8 months after endografting (range: 1-24 months). Intraprosthetic thrombotic deposits was not related to preoperative mural thrombus formation (p=0.38) or postoperative anti-platelet or anticoagulation medication (p=0.40). However, it was significantly related to the ratio of the cross-sectional area between the mainbody and the bilateral limb grafts and the length of mainbody (p=0.04 and p=0.01). There were three graft limbs occlusion owing to kinking with no intraprosthetic thrombus detected on CT scans taken prior to occlusion. One patient developed distal left proximal superior femoral artery embolisation 4 months after detectable intraprosthetic mainbody thrombus in a CT scan follow-up. In no case did the thrombotic deposits clear completely from the prosthesis lumen during follow-up. CONCLUSIONS This short experience demonstrates that incidentally found thrombotic deposits in abdominal aortic endografts are common. The deposition of thrombus is mostly influenced by the geometry of the aortic stent graft with wider mainbody diameter coupled with smaller limb grafts and longer mainbody graft. Most of these thrombi are clinically silent and require no additional treatment.

Massive Paradoxical Embolism Caught in the Act

A 33-year-old scientist with recent exertional shortness-of-breath presented with new onset right flank and groin pain. For weeks, he had spent over 16 hours a day at his desk writing a grant. History and physical examination revealed resting tachypnea, sinus tachycardia, tender right flank with (+) Giordano sign, and resting oxygen saturation of 91% on room air. Computed tomography showed recent right renal infarct and ventilation/perfusion scan revealed multiple areas of mismatch. Transthoracic and transesophageal echocardiography revealed a large “snake-like” mass waving in …A 33-year-old scientist with recent exertional shortness-of-breath presented with new onset right flank and groin pain. For weeks, he had spent over 16 hours a day at his desk writing a grant. History and physical examination revealed resting tachypnea, sinus tachycardia, tender right flank with (+) Giordano sign, and resting oxygen saturation of 91% on room air. Computed tomography showed recent right renal infarct and ventilation/perfusion scan revealed multiple areas of mismatch. Transthoracic and transesophageal echocardiography revealed a large “snake-like” mass waving in …

Association of lower extremity arterial calcification with amputation and mortality in patients with symptomatic peripheral artery disease.

Objective The clinical implication of the coronary artery calcium score (CS) is well demonstrated. However, little is known about the association between lower extremity arterial calcification and clinical outcomes. Methods and Results Eighty-two patients with symptomatic peripheral artery disease (age 61.0±12.4 years) were followed for 21±11 months. CSs, ranging from the common iliac artery bifurcation to the ankle area, were analyzed through noncontrast multidetector computed tomography images retrospectively. The primary endpoints of this study were amputation and mortality. Old age, diabetes, hyperlipidemia, and end-stage renal disease were associated with higher CSs. Patients with more advanced Fontaine stages also tended to have significantly higher CSs (p = 0.03). During the follow-up period (21±11 months), 29 (35%) patients underwent amputation, and 24 (29%) patients died. Among the patients who underwent amputation, there were no significant differences in CSs between the amputated legs and the non-amputated legs. In the Cox proportional hazard model with CS divided into quartiles, patients with CS in the highest quartile had a 2.88-fold (95% confidence interval [CI] 1.18–12.72, p = 0.03) and a 5.16-fold (95% CI 1.13–21.61, p = 0.04) higher risk for amputation and all-cause mortality, respectively, than those with CS in the lowest quartile. These predictive effects remained after conventional risk factor adjustment. Conclusion Lower extremity arterial CSs are associated with disease severity and outcomes, including amputation and all-cause mortality, in patients with symptomatic peripheral artery disease. However, the independent predictive value needs further investigation in large scale, prospective studies.

Clinical Experience of Tacrolimus With Everolimus in Heart Transplantation

BACKGROUND Tacrolimus (Tac) in combination with mycophenolate mofetil is widely used after heart transplantation (HT). Everolimus (EVR), a new potent proliferation signal inhibitor can be used with a carcineurin inhibitor to reduce the occurrence of rejection. The purpose of this study was to evaluate the efficacy and safety of Tac combined with EVR in de novo HT. MATERIALS AND METHODS From January 2009 to April 2011, 33/62 patients who underwent HT were prescribed Tac and EVR as de novo immunosuppression. The main exclusion criteria were poor kidney function (serum creatinine > 2.8 mg/dL), panel-reactive antibodies > 25%, donors > 60 years old, or cold ischemia time > 6 hours. All patients received Tac (C0 blood level 5-10 ng/mL during the first 6 months, then 3-5 ng/mL), EVR (C0 target 3-8 ng/mL), and corticosteroids. After transplantation, routine examinations included echocardiogram and protocol endomyocardial biopsy. RESULTS There was no operative mortality. The 1- and 3-year actuarial survivals were 95.74% ± 3.49%. One patient who had undergone coronary artery bypass grafting previously and received intra-aortic balloon pumping and extracorporeal membrane oxygenator-assisted cardiopulmonary resuscitation before HT died of Aspergillus septicemia 58 days after HT. No biopsy-proven acute rejection > grade 2R or acute rejection associated with hemodynamic compromise was observed. Hyperlipemia was noted in 16 cases (48.5%), hypertension in 11 (33.3% 5%), and diabetes mellitus in 12 (36.4%). No other severe adverse events were noted. CONCLUSIONS Concentration-controlled EVR (C0 target 3-8 ng/mL) in combination with Tac achieved good efficacy and safety. The 1- and 3-year actuarial survivals were 95.74% ± 3.49%.

Crossover Chimney Technique to Preserve the Internal Iliac Artery in Abdominal Aortic Aneurysm With Common Iliac Artery Aneurysms

Purpose To report a new technique to preserve the internal iliac artery (IIA) in cases of aortoiliac aneurysms. Technique Under bilateral common femoral artery (CFA) exposure, a crossover sheath was inserted from the contralateral CFA to the ipsilateral IIA involved in the common iliac artery (CIA) aneurysm. A Viabahn stent-graft was positioned 2 cm inside the IIA. The main body abdominal stent-graft was inserted through the ipsilateral CFA with distal sealing in the external iliac artery (EIA). The gate was cannulated, and the limb extension was positioned in the contralateral CIA near the IIA orifice. After the first Viabahn deployment, a second device was deployed with a minimum 1-cm overlap inside the first Viabahn and 2 mm distal to the limb extension. For bilateral CIA aneurysms, the Viabahn and extension limb were landed in the EIA with IIA embolization. In the past year, this technique has been used in 5 patients with success. There was no acute branch occlusion or type I endoleak from the IIA or chimney graft gutters on imaging studies up to 6 months. Conclusion This technique is easy to use and avoids the brachial access of the sandwich technique and the additional cost of an iliac branch device.

Can Cyclosporine Blood Level Be Reduced to Half After Heart Transplantation

BACKGROUND Cyclosporine (CsA) is widely used after heart transplantation. The purpose of this prospective randomized study was to evaluate the safety and efficacy of reduction of CsA blood level to one-half of the traditional blood concentration under a regimen of everolimus (EVL), CsA, and steroid. MATERIALS AND METHODS This prospective, 6 month, randomized, open-label study included adult (aged 18 to 65 years) recipients of a primary heart transplant with serum creatinine<or=2.8 mg/dL. Among 52 patients who underwent heart transplantation from December 2004 to March 2006 we excluded those who were hepatitis B or C carriers, who were recipients of organs from donors>60 years old, had cold ischemia time>6 hours, or had plasma renin activity>or=25%. All patients received CsA (C2 blood level 1000-1400 ng/mL), EVL (C0 target 3-8 ng/mL), and corticosteroids to day 60, before random entry into one of 2 groups: SE (C2 blood level from days 60-149=800-1200 ng/mL, and days 150-180 C2=600-1000 ng/mL), or RE group with CsA reduced by one-half after 3 months (days 90-149 C2=400-600 ng/mL, and from days 150-180 C2=300-500 ng/mL). RESULTS The 25 recipients eligible for this study included 13 patients in the SE and 12 in the RE group. There was no operative mortality in either group. No death or graft loss was noted within 6-months in either group. Mean serum creatinine at month 6 tended to be lower in the RE cohort (1.23+/-0.44 mg/dL versus 1.55+/-0.85 mg/dL; P=.093). Biopsy-proven acute rejection>or=grade 3A was observed in only 1 patient (7.7%), who was in the SE group. There were no acute rejection episodes associated with hemodynamic compromise. The incidences of adverse events in each group were similar. CONCLUSIONS Concentration-controlled EVL (C0 target 3-8 ng/mL) in combination with reduced CsA exposure of one-half the usual concentration achieved good efficacy and safety over 6 months. The renal function at 6 months among the RE group showed a trend toward improvement, suggesting a benefit of halving the target CsA blood level after heart transplantation.