Clinical Factors Implicated in Primary Graft Dysfunction After Heart Transplantation: A Single-center Experience.

BACKGROUND: Primary graft dysfunction (PGD) is a frequent complication after cardiac transplantation and remains one of the leading causes of mortality in these patients. The objective of this case-control study is to identify donor and surgical procedure's factors associated with PGD, and further guide possible strategies to prevent PGD. METHODS: Retrospective analysis of the medical records of patients who underwent cardiac transplantation at Memorial Hermann Hospital at Texas Medical Center between October 2012 and February 2015. RESULTS: The study population included 99 patients, of which 18 developed PGD. Univariate analysis of donor characteristics revealed opioid use (P = .049) and death owing to anoxia (P = .021) were associated with PGD. The recipient/donor blood type match AB/A was significantly associated with PGD (P = .031). Time from brain death to aortic cross clamp (TBDACC) of ≥3 and ≥5 days were also found to be associated with PGD (P = .0011 and .0003, respectively). Multivariate analysis confirmed that patients with a time from brain death to aortic cross clamp ≥3 and ≥5 days had lesser odds of developing PGD (odds ratio, 0.098 [P = .0026] and OR, 0.092 [P = .0017], respectively]. CONCLUSIONS: Our study showed that a longer time from brain death to aortic cross clamp was associated with lower odds of developing PGD. Therefore, postponing heart procurement for a few days after brain death seems to be beneficial in preventing PGD.

A pseudo-outbreak of disseminated cryptococcal disease after orthotopic heart transplantation.

Cryptococcal infection is the third most common invasive fungal infection (IFI) among solid-organ transplant (SOT) recipients and is considered an important opportunistic infection due to its significant morbidity and mortality. To determine whether a cluster of cryptococcosis in heart transplant patients was of nosocomial nature, three cases of orthotopic heart transplant recipients with postoperative disseminated cryptococcal infection were investigated and paired with an environmental survey in a tertiary care hospital. The infection prevention department conducted a multidisciplinary investigation, which did not demonstrate any evidence of health care-associated environmental exposure. Moreover, multilocus sequence typing showed that one isolate was unique and the two others, although identical, were not temporally related and belong to the most common type seen in the Southern US. Additionally, all three patients had preexisting abnormalities of the CT chest scan and various degrees of acute and chronic rejection. Reactivation was suggested in all three patients. Screening methods may be useful to identify at risk patients and trigger a prophylactic or preemptive approach. However, more data is needed.

Increased fatigability of the gastrocnemius medialis muscle in individuals with intermittent claudication.

BACKGROUND: We attempted to identify possible differences in the contractility of the gastrocnemius medialis (GM) muscle between healthy controls and individuals with peripheral arterial disease (PAD) and intermittent lower-limb claudication. METHODS: The GM muscles of 17 PAD patients and 17 healthy controls were examined with tensiomyography. Single or multiple electrical impulses were used to trigger muscle contractions, and the time and amplitude of contractions were measured. RESULTS: After single-impulse stimulation, the GM muscles of PAD patients showed significantly shorter contraction times (P < 0.001) than the GM muscles of controls. During 1 min of repetitive electrical stimulation, the contraction velocity of the controls' GM muscles typically showed a sustained increase throughout the stimulation period, whereas in PAD patients, a significant decrease in contraction velocity was observed after 30 s. The onset of muscle fatigue was unrelated to the ankle brachial index (ABI) of the examined leg. When the legs of PAD patients with higher and lower ABIs were compared to each other, no significant differences were found regarding the time and amplitude of contraction after single-impulse stimulation. CONCLUSIONS: The GM muscles of individuals with intermittent claudication contract more quickly and fatigue earlier than the GM muscles of healthy controls. Because the contraction time, measured with tensiomyography, reflects the individual's muscle fibre composition, our findings may reflect a shift from type I fibres to type II fibres in the GM muscles of PAD patients. Our data support the idea that calf myopathy is present in claudication-prone patients and, in part, determines the clinical manifestations of PAD.

Totally percutaneous aortic aneurysm repair: methods and outcomes using the fully integrated IntuiTrak endovascular system.

AIM: A totally percutaneous approach to endovascular abdominal aortic aneurysm repair (PEVAR) has been shown in multiple reports to be feasible, but carries attendant risks that appear to increase with increasing sheath size. We report our methods and sequential PEVAR case experience using a new delivery system having an integrated 19Fr introducer sheath for treatment of patients with aortic necks up to 32 mm in diameter. METHODS: A single institution, prospective, controlled evaluation was conducted in 57 consecutive patients with abdominal aortic aneurysm who underwent PEVAR between December 2008 and April 2010. All patients have been followed for at least 30 days. RESULTS: Patients presented at a mean age of 74 years with median AAA diameter of 5.4 cm preprocedurally. Calcified/tortuous access vessels were identified in 98% of patients. All PEVAR procedures with adjunctive "pre-close" use of the Prostar XL closure device were performed in a hybrid endovascular suite with patients maintained under conscious sedation and local anesthesia. The anatomically-fixed bifurcated stent graft and aortic/limb extensions as needed were implanted via the 19 Fr indwelling introducer sheath with minimal blood loss (79 mL). Technical success was 98%, with one conversion to open repair attributable to very small diameter (4 mm) access vessels. Cumulatively, major access-related complications were observed in five patients (8.8%) within 30 days. CONCLUSION: PEVAR using the IntuiTrak System with 19Fr introducer sheath with vessel closure facilitated by the Prostar XL device is feasible, even in patients with challenging access anatomy. Further evaluation in a prospective, multicenter, randomized trial is warranted.

Intramyocardial implantation of CD133+ stem cells improved cardiac function without bypass surgery.

INTRODUCTION: Cell transplantation for myocardial regeneration has been shown to have beneficial effects on cardiac function after myocardial infarction. Most clinical studies of intramyocardial cell transplantation were performed in combination with coronary artery bypass grafting (CABG). The contribution of implanted stem cells could yet not be clearly distinguished from the effect of the CABG surgery. Our current phase 1 clinical study has focused on the safety and feasibility of CD133+-enriched stem cell transplantation without CABG and its potential beneficial effect on cardiac function. METHOD AND RESULTS: Ten patients with end-stage chronic ischemic cardiomyopathy (ejection fraction <22%) were enrolled in the study. Bone marrow (up to 380 mL) was harvested from the iliac crest. CD133+ cells were purified from bone marrow cells using the CliniMACS device with purities up to 99%. Autologous bone marrow CD133+ cells (1.5-9.7 X 106 cells) were injected into predefined regions. Cardiac functions prior to and 3, 6, and 9 months after cell transplantation were assessed by cardiac magnetic resonance imaging. Stem cell transplantation typically improved the heart function stage from New York Heart Association/Canadian Cardiovascular Society class III-IV to I-II. The mean preoperative and postoperative ventricular ejection fractions were 15.8 +/- 5% and 24.8 +/- 5%, respectively. CONCLUSION: CD133+ injection into ischemic myocardium was feasible and safe. Stem cell transplantation alone improved cardiac function in all patients. This technique might hold promise as an alternative to medical management in patients with severe ischemic heart failure who are ineligible for conventional revascularization.

Aortic valve implantation in the calf: a successful approach using Heartport cannulation and minimally invasive techniques.

BACKGROUND AND AIM OF THE STUDY: Aortic valve replacement (AVR) for mechanical prosthetic valvular testing has not been performed in calves because of anatomic difficulties, and sheep have traditionally been used in this situation. Hemodynamically, however, the calf constitutes an excellent model due to vigorous myocardial contractility, high stroke volumes and high cardiac output, and so has been used for preclinical evaluation of mechanical assist devices and mechanical valves in the mitral and tricuspid positions, which can be approached with relative surgical ease. Recently, a juvenile bovine model has been used to test a newly developed mechanical valve in the aortic position. METHODS: Ten calves (body weight 91+/-11 kg) underwent AVR with a 21-mm mechanical prosthesis via a small left intercostal thoracotomy with the aid of a Heartport cannulation device. A standard cardiopulmonary bypass (CPB) circuit was used. To circumvent the short bovine ascending aorta and to gain additional space to perform the aortotomy, two aortic cannulas were inserted for arterial-systemic perfusion. Nine calves each received a 21-mm experimental trileaflet aortic central flow valve prosthesis, and one calf received a 21-mm St. Jude Medical prosthesis. RESULTS: Mean CPB duration was 154.2+/-44.4 min, and mean ischemic time 80.1+/-15.9 min. Mean study duration was 42.6+/-53.7 days. Three calves were killed prematurely: two on days 2 and 7 due to complications arising from inadvertent entrapment of the right coronary artery ostium by a suture, and one on day 0 due to an accidental overdose of magnesium. Three calves, all of which had a first-version test valve, were killed electively due to valve malfunction secondary to early valvular thrombosis. Four animals (three with the final version valve and one with a standard valve as a control) survived until killed electively (range: 33-172 days). CONCLUSION: Results indicate that replacement of the native bovine aortic valve with a mechanical prosthesis can be performed safely in calves. Complication-free survival of up to six months can be achieved in the growing calf, provided that the test valve design satisfies minimum hemodynamic and coagulation criteria.

Research and development of an implantable, axial-flow left ventricular assist device: the Jarvik 2000 Heart.

Advances in technology and increased clinical need have led to the development of a new type of blood pump. The Jarvik 2000 Heart is an electrically powered, axial-flow left ventricular assist device that has been developed during the past 13 years. Unlike first-generation left ventricular assist devices, which were developed in the 1970s and were designed to totally capture the cardiac output, the Jarvik 2000 is designed to normalize the cardiac output by augmenting the function of the chronically failed heart for extended periods. Design iterations have been tested in 67 animals, and clinical trials have recently begun. Three patients have received the Jarvik 2000 as a bridge to transplantation, and 1 patient is being supported permanently outside the hospital. All 4 patients have improved from New York Heart Association functional class IV to class I, and 2 of them have been discharged from the hospital after heart transplantation. The experimental and clinical results indicate that the Jarvik 2000 can provide physiologic support with minimal complications and is reliable, biocompatible, and easy to implant.

Concomitant subclavian and coronary artery disease.

BACKGROUND: Proximal subclavian artery occlusive disease in the presence of a patent internal mammary artery used as a conduit for a coronary artery bypass graft procedure may cause reversal of internal mammary artery flow (coronary-subclavian steal) and produce myocardial ischemia. METHODS: We reviewed outcome to determine whether subclavian artery revascularization can provide effective protection from and treatment for coronary-subclavian steal. Between 1985 and 1997, 20 patients had either concomitant subclavian and coronary artery disease diagnosed before operation (group 1, 5 patients) or symptomatic coronary-subclavian steal occurring after a previous coronary artery bypass graft procedure (group 2, 15 patients). Patients in group 1 received direct subclavian artery bypass and a simultaneous coronary artery bypass graft procedure in which the ipsilateral internal mammary artery was used for at least one of the bypass conduits. Patients in group 2 received either extrathoracic subclavian-carotid bypass (5 patients, 33.3%) or percutaneous transluminal angioplasty and stenting (10 patients, 66.7%) as treatment for symptomatic coronary-subclavian steal. RESULTS: All patients were symptom-free after intervention. One patient treated with percutaneous transluminal angioplasty and stenting died of progressive renal failure. Follow-up totaled 58.5 patient-years (mean, 3.1 years/patient). In group 1, primary patency was 100% (mean follow-up, 3.7 years). In group 2, one late recurrence was treated by operative revision, yielding a secondary patency rate of 100% (mean follow-up, 2.9 years). CONCLUSIONS: Subclavian artery revascularization can provide effective protection from and treatment for coronary-subclavian steal with acceptably low operative risk. Midterm follow-up demonstrates good patency.

Effects of myocardial contractility on microemboli production by mechanical heart valves in a bovine model.

Microemboli caused by mechanical heart valves have the potential to cause cerebrovascular events. We investigated the effects of myocardial contractility and heart rate on microemboli production in association with conventional and experimental mechanical heart valves implanted in the mitral position in a bovine model. In 10 calves, the mitral valves were replaced with mechanical valves. Doppler recordings were analyzed for high-intensity transient signals, which are ultrasound reflections from circulating microemboli. The animals were studied at rest, during pacing at 160 bpm, after dobutamine infusion, and after esmolol infusion. The incidence of high intensity transient signals was expressed as signal frequency (signals per hour) and as signal rate (signals per 100 heart cycles). With a 68% increase in the heart rate, signal frequency increased by 135%, but signal rate increased by only 41 %. With a 144% increase in myocardial contractility, signal rate increased by 264 %. With a 31 % decrease in contractility, signal rate decreased by 62 %. We conclude that microemboli production by mechanical heart valves varies with myocardial contractility and heart rate. The fact that contractility affects the incidence of high-intensity transient signals suggests that the microemboli are gaseous in nature, that their production is pressure driven, and that cavitation is a possible cause. It is likely that mechanical heart valve design is responsible for the quantity of microemboli production.

Normalization of native heart function years after heterotopic transplantation.

We describe a patient whose native heart function has normalized several years after heterotopic heart transplantation. The native heart sustained the patient's circulation at a time when the donor heart was temporarily dysfunctional. Native heart improvement, let alone normalization, is considered rare after heterotopic transplantation but has been noted with increased frequency after long-term unloading with left ventricular assistance.

Left ventricular reduction in a Jehovah's Witness.

For Jehovah's Witnesses with severe heart failure, left ventricular reduction surgery may be a satisfactory alternative to cardiac transplantation. Compared with transplantation, left ventricular reduction surgery can involve less blood loss thus decreasing the need for blood-volume replacement. More importantly, left ventricular reduction surgery obviates the need for a donor organ.

A bovine model for detecting high intensity transient signals originating from mechanical heart valves.

In patients with mechanical heart valves (MHVs), transcranial Doppler methods commonly detect high intensity transient signals (HITS) representing microemboli. These microemboli, which are presumably gaseous, may cause stroke and cognitive deterioration. A bovine model was therefore developed for studying the relationship between mitral MHV induced HITS and potential etiogenic factors. We placed an 18 mm, 4 MHz Doppler probe in the brachiocephalic artery to detect MHV induced microbubbles at baseline (rest) and under 9 other conditions. To elucidate the gas composition (CO2 or N2) of the microbubbles, we administered 1%, 3%, and 5% CO2, and 100% O2. To determine effect of the heart rate, we paced the heart at 120, 160, and 180 bpm. To alter the myocardial contractility, we gave dobutamine and esmolol. Two independent, blinded observers counted the HITS from recorded doppler spectra. HITS were defined by an initial unidirectional spectral deviation, a signal power of >8 dB relative to the background power, and lack of a cyclic appearance. The electrocardiogram, aortic and LV pressures, and LV dP/dt were obtained telemetrically. The calves were studied 4 to 6, 8 to 10, and 12 to 14 weeks postoperatively, after which the animals were sacrificed at an approximate 4 month study duration, and a postmortem evaluation of the heart and the main viscera was performed. In all, 27 HITS recordings were made in 10 calves. Myocardial contractility was the only factor to significantly affect HITS frequency; the heart rate and blood gas concentrations had minimal effect on HITS frequency. Our bovine model will be useful for assessing valve designs, as well as the mechanism of HITS, the composition of the microemboli, and their possible pathophysiologic effects on the kidneys and brain.

Extrapleural suction buttress of primary esophageal repair.

Buttress reinforcement of a primary esophageal repair after perforation may diminish the potential for breakdown or leakage of the approximation. We describe a method of reinforcing a primary esophageal repair by using pleural tissue that is secured in place with an extrapleural, soft T-tube attached to a suction device. This technique is simple to apply and may maximize recovery of respiratory function by permitting timely removal of chest tubes.

Creation of a distal arteriovenous fistula improves microcirculatory hemodynamics of prosthetic graft bypass in secondary limb salvage procedures.

PURPOSE: In patients with critical limb ischemia, poor distal arterial runoff, and absence of autogenous veins, the use of an artificial graft and an arteriovenous fistula might be a valuable option. However, in these patients little information is available regarding preoperative and postoperative microcirculatory hemodynamics after this type of intervention. METHODS: With the use of intravital capillary microscopy, we studied the effect of distal revascularization on the microcirculation in 26 patients with critical limb ischemia. All patients had had failed vascular reconstructive operations, and artificial grafts were required because of the absence of autogenous veins. Patients were prospectively investigated and divided into two groups: 12 patients received a femorocrural bypass with polytetrafluoroethylene grafts, and 14 patients underwent the same procedure with the creation of an arteriovenous fistula at the site of the distal anastomosis and ligation of the proximal vein. Red blood cell velocity was measured before and after arterial occlusion to determine microcirculatory hemodynamic alterations. RESULTS: Immediate postoperative graft patency was achieved in all 26 patients. The 1-year cumulative graft patency rate was 64% in the group that had creation of an arteriovenous fistula, which was significantly higher (p < 0.01) compared with that in the group in which a fistula was not created (21%). The 1-year cumulative foot salvage rate was 72% in the patients with an arteriovenous fistula and 43% in the patients without a fistula (p < 0.05). Red blood cell velocity increased similarly in both groups after the bypass procedure. Peak and time to peak red blood cell velocity also improved significantly in both groups; however, comparing both groups, peak and time to peak red blood cell velocity were significantly better (p < 0.05) in the patients with an arteriovenous fistula and remained significantly higher during the follow-up period. CONCLUSIONS: In conclusion, creation of an adjunctive arteriovenous fistula at the distal anastomosis of a prosthetic graft appears to improve microcirculatory hemodynamics in the nutritional capillary vascular bed. Improved graft patency and foot salvage rates suggest that this procedure benefits patients with critical limb ischemia who have no usable veins.

Creation of a systemic-to-pulmonary artery shunt by use of an internal mammary artery.

The creation of a systemic-to-pulmonary artery shunt by use of the internal mammary artery (IMA) in a 2-year-old boy with complex congenital heart defects and diminutive pulmonary arteries is described. This procedure may offer advantages over standard methods in selected patients with extremely small pulmonary arteries. The pliability, favorable anatomical position, and growth capability of the IMA reduce chances for complications, such as stenosing, kinking, and stretching of the pulmonary artery, which can cause it to become distorted, making further definitive repair difficult.

Long-term results of the surgical management of symptomatic chronic intestinal ischemia.

We analyzed our surgical experience in 20 patients who underwent revascularization procedures for symptomatic chronic intestinal ischemia caused by atherosclerosis. The group comprised 17 women and 3 men, with an age range of 25 to 71 years (mean 58.6 years). Sixteen patients had postprandial abdominal pain, and 4 had pain not related to eating. The average weight loss was 23.8 lb. Malabsorption and diarrhea were present in 8 patients. The duration of the symptoms was from 4 to 46 months (mean 13.4 months). One patient presented with acute intestinal ischemia following balloon angioplasty reocclusion of a stenotic celiac artery, and 3 underwent surgery for stenosis of a previously placed graft. Five patients had single mesenteric artery involvement, 10 had double-artery involvement, and 5 had significant occlusion in all 3 mesenteric arteries. The major arteries were revascularized whenever technically possible; therefore, 36 arteries were revascularized in 20 patients. Bypass grafts were done in 27 vessels, reimplantation in 7, and endarterectomy with patch angioplasty in 2. The saphenous vein was used in 12 vessels, polytetrafluoroethylene grafts in 8, dacron in 6, and inferior mesenteric vein in 1. The type of revascularization or graft utilized did not affect long-term patency. Two patients had early graft thrombosis and required intestinal resection. All patients survived the operation. At a mean follow-up of 36 months, all 20 patients were alive and asymptomatic with regard to their abdominal complaint. Ten patients (50%) underwent postoperative abdominal angiography; all the grafts were patent.(ABSTRACT TRUNCATED AT 250 WORDS)

Profunda femoral artery pseudoaneurysm after percutaneous transluminal procedures manifested by neuropathy.

The incidence of arterial complications following femoral artery cannulation is low; however, with the increasing number of cardiac diagnostic and interventional procedures, vascular surgeons are being confronted with an increasing number of pseudoaneurysms and arteriovenous fistulas. Swelling and a painful pulsating groin masse are the most frequent presenting symptoms of a common femoral artery false aneurysm. We present the cases of 4 patients who had the unusual finding of a profunda femoral artery pseudoaneurysm after they had undergone cardiac catheterization or percutaneous transluminal coronary angioplasty. The only clinical sign of these patients was femoral neuropathy or neuropalsy caused by femoral nerve compression. Surgical repair of the pseudoaneurysm was successful in all patients. We discuss the reasons for this unusual finding and rare location for a pseudoaneurysm.