Kalpesh T. Vakharia

Effects of Intravenous Levosimendan on Human Coronary Vasomotor Regulation, Left Ventricular Wall Stress, and Myocardial Oxygen Uptake

Background—Levosimendan is a calcium-sensitizing agent and an inodilator under current investigation in the treatment of decompensated heart failure. The effects of intravenous levosimendan on the human coronary vasculature, together with myocardial wall stress and oxygen uptake, have not been adequately studied. Methods and Results—Ten adult patients underwent right- and left-heart catheterization. Baseline coronary blood flow was determined with quantitative coronary angiography and an intracoronary Doppler-tipped guidewire. Myocardial oxygen uptake was measured with a coronary sinus catheter. Echocardiography was performed before and 30 minutes after an intravenous infusion of levosimendan (24-&mgr;g/kg bolus over 10 minutes) was begun. Pulmonary capillary wedge decreased 37% (P=0.009), cardiac output increased 9% (P=0.04), and systemic vascular resistance decreased 18% (P<0.001). Left ventricular ejection fraction increased 20% (P=0.009), and meridional systolic wall stress decreased 48% (P=0.009). Coronary artery diameter increased 10% at 15 minutes (P=0.001) and 11% at 30 minutes (P=0.01). Coronary artery velocity increased 10% over baseline (P=0.04). Coronary blood flow increased 45% (P=0.02), whereas coronary resistance decreased 36% at 30 minutes (P=0.03). Myocardial oxygen extraction decreased 9% at 30 minutes (P=0.04). Conclusions—Levosimendan given intravenously exerts vasodilator effects on human coronary conductance and resistance arteries. Despite a decrease in coronary perfusion pressure, coronary blood flow is increased. A reduction in coronary vascular resistance and a decrease in coronary venous oxygen content indicate primary coronary vasodilation by levosimendan. Improved left ventricular systolic function and decreased myocardial oxygen extraction suggest improved myocardial efficiency.

Determination of adequate coronary stent expansion using StentBoost, a novel fluoroscopic image processing technique.

We tested the hypothesis that the use of motion‐corrected fluoroscopic images results in enhanced coronary stent visualization and improved detection of inadequate stent expansion.

Randomized study of the safety and clinical utility of rotational vs. standard coronary angiography using a flat-panel detector

The purpose of this study was to test the hypothesis that rotational angiography improves patient safety while maintaining diagnostic accuracy for patients undergoing coronary angiography. Despite advances in angiographic technique, patients remain at risk for complications of coronary angiography, including contrast‐induced nephropathy and radiation exposure. Technology has been developed to perform coronary angiography with active rotation of the imaging system that may reduce the quantity of contrast and radiation to which the patient is exposed. Fifty patients undergoing diagnostic cardiac catheterization were randomized to either standard vs. rotational angiography of the coronary arteries using a prespecified protocol with a flat‐panel single‐plane imaging system. We measured the quantity of radiographic contrast utilized and radiation exposure. Using an intention‐to‐treat analysis, there was a 40% reduction (24 ± 5 vs. 40 ± 10 ml; P < 0.0001) in contrast utilization in the rotational group compared to the standard group. Neither radiation exposure (35 ± 14 vs. 30 ± 20 Gycm2; P = 0.35), fluoroscopic time (44 ± 33 vs. 44 ± 40 sec; P = 0.99), nor procedure time (249 ± 137 vs. 214 ± 79 sec; P = 0.26) differed, although significant intraoperator variability was noted for both standard and rotational angiography. The radiation exposure using this flat‐panel system is significantly lower than prior reports that used an image intensifier system. Rotational coronary angiography has the potential to improve patient safety by markedly reducing radiographic contrast exposure while maintaining comparable diagnostic accuracy, radiation exposure, and procedure time compared to standard coronary angiography.

Demographic disparities among children with frequent ear infections in the United States

To evaluate current racial/ethnic and socioeconomic disparities in the prevalence of frequent ear infections (FEI) among children in the United States.

Quality-of-life impact of participation in a head and neck cancer support group

Objective To assess if participation by patients in a head and neck cancer support group improves perceived quality of life (QOL). Study Design and Setting Subjects for this study included 47 patients at a tertiary Veterans Affairs Medical Center who were previously treated for head and neck cancer. This was a quasi-experimental, post-test study comparing the QOL of 24 patients who participated in a head and neck cancer support group with 23 patients who did not participate. The validated University of Michigan Head and Neck Quality of Life (HNQOL) instrument was used to evaluate head and neck cancer-related QOL. Results Patients who participated in the head and neck cancer support group exhibited significantly better scores in the domains of eating, emotion, and pain as well as in the global bother and response to treatment questions of the HNQOL instrument compared with those patients who did not participate. Additional subgroup analysis comparing age, type of treatment, and length of time since cancer diagnosis suggests that these variables were less important predictors of QOL than was support group participation. Conclusions Our findings suggest that patient participation in a head and neck cancer support group is associated with improved QOL. Significance Support groups may be beneficial in improving QOL after head and neck cancer treatment.

Color Doppler ultrasound: effective monitoring of the buried free flap in facial reanimation.

Objective. The gracilis muscle free flap has become a reliable means for smile reanimation for patients with facial paralysis. Because it is a buried flap, it presents a postoperative monitoring challenge. We sought to evaluate our experience with color Doppler ultrasound in the monitoring of gracilis free flap viability in the immediate postoperative setting. Study Design. Case series with planned data collection. Setting. Tertiary medical center. Methods. Patients with facial paralysis treated with gracilis muscle free flap for smile reanimation performed between March 2009 and November 2010 were evaluated by color Doppler ultrasound and included in the study. Our experience with the use of the color Doppler ultrasound to monitor the gracilis muscle flap is presented. Results. Forty-six patients were identified. In all cases, color Doppler ultrasound was used postoperatively to assess flow through the vascular pedicle. Outcomes included an early flap survival rate of 100%, with no instances of equivocal or absent flow on either the arterial or venous side. Color Doppler ultrasound provided important objective information regarding muscle perfusion postoperatively in several instances of equivocal postoperative perfusion of the flap. Conclusion. Color Doppler ultrasound is a safe, noninvasive method that can be performed serially to evaluate a buried free flap. We have had success in verifying normal arterial and venous flow through the pedicle using this method of monitoring of the gracilis muscle free flap during facial reanimation, and in 3 instances, it eliminated the need for wound exploration to verify appropriate muscle perfusion.

Influence of race and ethnicity on access to care among children with frequent ear infections.

OBJECTIVE Determine the impact of racial/ethnic disparities on access to care for children with frequent ear infections (FEI). Identify disparities to target for intervention. STUDY DESIGN Cross-sectional analysis of national database. SETTING Academic medical center. SUBJECTS AND METHODS The National Health Interview Survey (1997 to 2006) was utilized to identify children with FEI (defined as three or more ear infections in the preceding year). Age, sex, race/ethnicity, income level, and insurance status were extracted. Access to care was measured by ability to afford medical care and prescription medications, specialist visitation, and emergency department visits. Multivariate analysis determined the influence of demographic variables on the ability to access health care resources. RESULTS An annualized population of 4.65 ± 0.08 million children reported FEI. Overall, 3.7 percent could not afford care, 5.6 percent could not afford prescriptions, and only 25.8 percent saw a specialist. A larger percentage of the black (42.7%) and Hispanic children (34.5%) with FEI were below the poverty level, versus white children (12.4%; P < 0.001); 18.2 percent of Hispanic children were uninsured, versus 6.5 percent of white children (P < 0.001). On multivariate analysis, children with FEI that were black or Hispanic had increased odds ratios relative to white children for 1) not being able to afford prescription medications (odds ratios [OR] 1.76 and 1.47, respectively; P < 0.002); 2) not being able to see a specialist (OR 1.62 and 1.86, respectively; P < 0.001); and 3) visiting the emergency department (OR 2.50 and 1.32, respectively; P < 0.001). CONCLUSION Racial/ethnic disparities among children with FEI significantly influence health care resource access and utilization. These disparities should be targeted for intervention.

Daily Facial Stimulation to Improve Recovery After Facial Nerve Repair in Rats

OBJECTIVE To establish whether daily mechanical stimulation improves functional recovery of whisking after facial nerve transection injury and repair in rats. METHODS Forty rats underwent facial nerve transection injury and repair and subsequent quantitative facial movement testing. Animals were randomized into 2 experimental groups (n = 20 each). Both groups received daily 5-minute manual stimulation of their whiskers, with one group undergoing whisker protraction and the other, whisker retraction. Rats were tested on postoperative weeks 1, 4 through 8, and 15 via a validated, quantitative whisking kinematics apparatus. Whisks were counted and analyzed for whisking amplitude, velocity, and acceleration. RESULTS Animals receiving manual stimulation by passive protraction of their whiskers demonstrated significantly improved functional recovery at multiple time points during the 15 weeks compared with historical controls (P < .005; 1-tailed t test). Recovery was similar in the protraction and retraction groups, trending toward better whisking recovery in the protraction group. CONCLUSIONS Daily mechanical whisker stimulation via either protraction or retraction significantly improves recovery of whisking after facial nerve transection and repair. This finding supports the role of early soft-tissue manipulation after facial nerve repair and may have clinical implications for the postoperative management of patients after facial nerve manipulations.

The convergence of facial nerve branches providing whisker pad motor supply in rats: Implications for facial reanimation study

Rodent whisking behavior is supported by the buccal and mandibular branches of the facial nerve, but a description of how these branches converge and contribute to whisker movement is lacking.

Facial reanimation of patients with neurofibromatosis type 2.

BACKGROUND: Neurofibromatosis type 2 (NF2) is a tumor suppressor syndrome defined by bilateral vestibular schwannomas. Facial paralysis, from either tumor growth or surgical intervention, is a devastating complication of this disorder and can contribute to disfigurement and corneal keratopathy. Historically, physicians have not attempted to treat facial paralysis in these patients. OBJECTIVE: To review our clinical experience with free gracilis muscle transfer for the purpose of facial reanimation in patients with NF2. METHODS: Five patients with NF2 and complete unilateral facial paralysis were referred to the facial nerve center at our institution. Charts and operative reports were reviewed; treatment details and functional outcomes are reported. RESULTS: Patients were treated between 2006 and 2009. Three patients were men and 2 were women. The age of presentation of debilitating facial paralysis ranged from 12 to 50 years. All patients were treated with a single-stage free gracilis muscle transfer for smile reanimation. Each obturator nerve of the gracilis was coapted to the masseteric branch of the trigeminal nerve. Measurement of oral commissure excursions at rest and with smile preoperatively and postoperatively revealed an improved and nearly symmetric smile in all cases. CONCLUSION: Management of facial paralysis is oftentimes overlooked when defining a care plan for NF2 patients who typically have multiple brain and spine tumors. The paralyzed smile may be treated successfully with single-stage free gracilis muscle transfer in the motivated patient. ABBREVIATION: NF2, neurofibromatosis type 2