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Biomedical subjects

R A Marks

Publications and source records attributed to R A Marks.

17 recordsLinked to original sources
PubMed2000

Nonoperative treatments for sciatica: a pilot study for a randomized clinical trial.

OBJECTIVES: To assess the feasibility of patient recruitment, the ability of patients and clinicians to comply with study protocols, and the use of data collection instruments to collect cost-effectiveness data, and to obtain variability estimates for sample-size calculations for a full-scale trial. STUDY DESIGN: Prospective, observer-blinded, pilot randomized clinical trial. SETTING: Primary contact chiropractic and medical clinics. PATIENTS: Ages 20 to 65 years, with low back-related radiating leg pain (sciatica). OUTCOME MEASURES: Self-report questionnaires were administered at baseline and 3 and 12 weeks after randomization. The measures included leg and back pain severity, frequency and bothersomeness of symptoms, leg/back disability, medication use, global improvement, satisfaction, and health care utilization. INTERVENTIONS: Medical care, chiropractic care, and epidural steroid injections. RESULTS: A total of 706 persons were screened by phone to determine initial eligibility. Of these, over 90% of those persons contacted did not meet the entrance criteria. The most common reason for disqualification was that the duration of the complaint was longer than 3 months. Twenty patients were randomized into the study. All 3 groups showed substantial improvements in the main patient-rated outcomes at the end of the 12-week intervention phase. For leg pain, back pain, frequency and bothersomeness of leg symptoms, and Roland-Morris disability score, the percent improvement varied from 50% to 84%, and the corresponding effect sizes ranged from 0.8 to 2.2. Bothersomeness of leg symptoms was the most responsive outcome associated with the largest magnitude of effect size. All within-group changes from baseline were statistically significant (P <.01). No between-group comparisons were planned or performed because of the insufficient sample size and high risk of committing type I and type II errors. CONCLUSIONS: Pilot studies such as these are important for the determination of the feasibility of conducting costly, larger scale trials. Recruitment for a full-scale study of sciatica of 2 to 12 weeks duration is not feasible, given the methods used in this pilot study. Our results do indicate, however, that there are substantial numbers of patients with sciatica more chronic in nature who would be interested in participating in a similar study. In addition, collaboration with a local health maintenance organization would likely facilitate clinician referrals and optimize the recruitment process. Patient and provider compliance was high in the pilot study, which indicates that most study protocols are feasible. Additionally, we were able to collect complete outcomes data, including those regarding health care use. A suggested modification by investigators and outside consultants has resulted in the replacement of the medication group with a minimal intervention control group (ie, self-care advice). As a result, a second pilot study of patients with sciatica of more than 4 weeks duration has been planned before a full-scale trial is attempted.

Adult↗
PubMed2000

Transcutaneous lumbar diskectomy for internal disk derangement: a new indication.

BACKGROUND: Percutaneous diskectomy has been used effectively to treat lumbar disk herniation. The purpose of this review was to determine whether transcutaneous diskectomy is an effective surgical option for treating lumbar internal disk derangement. METHODS: Comprehensive retrospective review via personal interview included 103 consecutive patients available for long-term follow-up. For determining results as excellent, good, fair, or poor, the criteria included subjective relief of back and/or leg pain, ability to perform preinjury job functions, residual physical restrictions, use of medications, and need for subsequent surgery. Factors affecting results were statistically analyzed. RESULTS: The overall success rate was 83%, with no statistically significant differences in results based on sex, workers' compensation status, or levels of diskectomy. CONCLUSIONS: The favorable results from this series illustrate the high success rate of transcutaneous lumbar diskectomy in a heterogeneous patient population. Coupling the rate of success with a low rate of complications, transcutaneous lumbar diskectomy appears to be an effective, minimally invasive treatment for internal disk derangement.

Activities of Daily Living↗
PubMed1998

Analgesic effect of bupivacaine on extraperitoneal laparoscopic hernia repair.

UNLABELLED: Local anesthetics decrease postoperative pain when placed at the surgical site. Patients benefit from laparoscopic extraperitoneal hernia repair because this allows earlier mobilization than the more classical open surgical approach. The purpose of this study was to determine the pain-sparing efficacy of local anesthetics placed in the preperitoneal fascial plane during extraperitoneal laparoscopic inguinal hernia surgery. Forty-two outpatients were included in a double-blind, randomized, placebo-controlled, institutional review board-approved study. At the conclusion of a standardized general anesthetic, 21 patients received 60 mL of 0.125% bupivacaine into the preperitoneal fascial plane before incisional closure, whereas the other 21 patients received 60 mL of the isotonic sodium chloride solution placebo. Postoperative pain was assessed 1, 4, 8, 24, and 72 h postoperatively. In addition, postoperative fentanyl and outpatient acetaminophen 500 mg/hydrocodone 5 mg requirements were recorded. All hernia repairs were performed by the same surgeon. Appropriate statistical analyses were used. There were no significant differences between the bupivacaine and isotonic sodium chloride solution groups with regard to postoperative pain scores, length of postanesthesia care unit stay, or analgesic requirements. Furthermore, neither unilateral versus bilateral repair nor operative time affected the measured parameters. The addition of 60 mL of 0.125% bupivacaine into the preperitoneal fascial plane during extraperitoneal laparoscopic hernia repair did not significantly alter pain scores, supplementary analgesic requirements, or recovery room length of stay. IMPLICATIONS: The placement of 60 mL of 0.125% bupivacaine into the preperitoneal fascial plane during extraperitoneal laparoscopic hernia repair did not significantly alter pain scores, supplementary analgesic requirements, or recovery room length of stay.

Anesthetics, Local↗
PubMed1989

Gastric and hepatic infarction following embolization of the left gastric artery: case report.

The authors report an initially successful left gastric artery embolization performed because of massive upper gastrointestinal bleeding; the procedure was complicated by focal gastric and hepatic infarctions. These complications occurred in the absence of underlying factors known to predispose to ischemia. Low-grade gastric bleeding persisting after seemingly successful embolization of the left gastric artery may indicate ischemic gastritis and is an indication for endoscopy. In addition, the presence of a left hepatic artery completely replaced to the left gastric artery should alert one to the potential for hepatic necrosis.

Aged↗
PubMed1984

Diagnosis of isolated perforation of the gallbladder following blunt trauma using sonography and CT scan.

Perforation of the gallbladder from blunt abdominal trauma is relatively rare, and is usually diagnosed at laparotomy for associated visceral injury. Isolated injury of the gallbladder may be unrecognized leading to delayed diagnosis and its associated increased morbidity. Computerized tomography, sonography, and HIDA Tc99m may be used in the early diagnosis of the acutely perforated gallbladder.

Abdominal Injuries↗
PubMed1978

Accuracy of echocardiography in assessing left ventricular dimensions and volume.

The accuracy of determining left ventricular function from echocardiography was assessed in 26 children (group I) with cineangiographically-determined normal left ventricular volume (LVV) and 28 children (group II) with large left ventricular volumes. Conventional LV echo dimensions were compared to the cineangiographic LV anterior-posterior minor axis (LVmA) and LVV. Very good correlations were found in group I between LV end-diastolic echo dimensions (LVEDD) and cine LVmA (r = 0.91) and between LVEDD and LV end-diastolic volume (LVEDV) by cine in group I (r = 0.86). In group II correlations were less accurate between LVEDD and diastolic LVmA and between LVEDD and LVEDV. There was poor correlation between the cine and echo percent of shortening (r = 0.41) and velocity of circumferential fiber shortening (VCF) (r = 0.51). This study demonstrates that M-mode echocardiography is a very useful method for determining LV dimensions in children with normal LV volume, but is less accurate in children with left ventricular volume overload or with abnormal septal orientation or postoperative status after ventriculotomy.

Adolescent↗
PubMed1977

Pre and postoperative ventricular function in infants and children with right ventricular volume overload.

Hemodynamic and ventricular volume parameters were evaluated in 21 patients (24 studies) with total anomalous pulmonary venous return (TAPVR), 11 patients with secundum atrial septal defect (ASD), and eight patients who had complete correction of TAPVR or ASD. Right and left ventricular (RV and LV) volume parameters were calculated according to Simpson's rule and the area length methods, respectively. In infants with TAPVR, RV end-diastolic volume was larger than normal, but RV ejection fraction was significantly less than normal. LV end-diastolic volume and LV ejection fraction were all less than normal in infants with or without pulmonary hypertension, and the values did not correlate with the cardiorespiratory symptoms. In children with TAPVR or ASD, RV end-diastolic volume and output were higher than normal preoperatively and decreased to normal or near normal values postoperatively. The data suggest that pulmonary venous obstruction and/or RV failure are responsible for cardiorespiratory symptoms in infants with TAPVR and early surgical intervention is recommended in these patients.

Blood Volume↗
PubMed1976

Effect of reperfusion on myocardial infarct, and the accuracy of estimating infarct size from serum creatine phosphokinase in the dog.

This study was designed to determine the effect of coronary reperfusion on (1) myocardial infarct size and (2) the accuracy of previously reported methods for estimation of infarct size serum creatine phosphokinase (CPK) values. Thirty mongrel dogs, chronically prepared, were studied in the awake state, and were divided into four groups according to the period or left circumflex coronary artery (LCCA) occlusion. Group 1: permanent occlusion (24 h) in nine dogs; group 2: 45 min occlusion (eight dogs); group 3: 1 h occlusion (five dogs); and group 4: 3 h occlusion (eight dogs). Serial blood samples were drawn for 24 h following the beginning of occlusion and were used to determine total and isoenzyme levels of CPK, and lactic dehydrogenase isoenzymes. All dogs were sacrified 24 h after the beginning of occlusion and were anatomically examined. The extent of anatomical myocardial infarction was determined and compared with the extent of myocardial infarction as estimated from serial serum CPK values. Total serum CPK increased significantly in all groups and was associated with the appearance of CPK-MB isoenzyme and an increase in LDH1,2 (LDH1 greater than LDH2) in most dogs. Total serum CPK increased within an hour after reperfusion and the mean values in groups 2, 3, and 4 were significantly high (P less than 0.05) than serum CPK values in group 1 in the period from 110 min to 4 after occlusion. These data demonstrate that reperfusion after 45 min to 3 h of coronary occlusion results in an earlier appearance of total serum CPK. The anatomical infarction in group 1 averaged 28% +/- 3% (SEM) of the total heart and was significantly larger than infarct size in all groups with reperfusion. In contrast, estimated infarction calculated from total CPK in group 1 was not significantly different from the reperfused groups. Although there was correlation between estimated and anatomical infarction, the data in each group showed that anatomical infarct size could not be accurately estimated from total serum CPK.

Animals↗
PubMed1976

Echocardiographic determination of left atrial volumes in children with congenital heart disease.

The feasibility of determining left atrial volumes (LAV) from LA echo dimensions was assessed in 36 children (group I) with normal cineangiographically determined LAV and 16 children (group II) with LAV overload. Conventional LA echo dimensions, obtained within 24 hours of cardiac catheterization, were compared to the angiographic LA anterior-posterior minor axes (LAmA) and LAV. There was excellent correlation betweeh the LA echo dimensions and the LAmA. In all patients, the LA echo less than LAmA, the differences being more pronounced in group II. Good correlations were found between the LAV and the LA echo, and were expressed by the equations LAV = 7.5 LA echo1.8 (r = .85) and LAV = 8.1 LA echo2.1 (r = .86) for groups I and II, respectively. Changes in LA configuration with volume overload were shown to cause a disproportionate increase in LAmA compared to the other LA dimensions and the LA echo dimension, thus necessitating the separate regression equations. Echo LA to aortic ratios were 0.86 +/- 0.11 and 1.21 +/- 0.23 (mean +/- SD) for groups I and II, respectively. This method of estimating LAV can be useful in the management of left-to-right intracardiac shunts and mitral regurgitation in infants and children.

Adolescent↗
PubMed1976

Right ventricular function in children with tetralogy of Fallot before and after aortic-to-pulmonary shunt.

Right and left ventricular volume variables were obtained in 43 tetralogy patients undergoing diagnostic cardiac catheterization. The patient population consisted of 25 preoperative patients (group 1) and 18 patients who had undergone aortic-to-pulmonary shunt procedure (group 2). Volumes were calculated from biplane cineangiocardiograms using Simpson's rule method for the right ventricle (RV) and the area-length methods for the left ventricle (LV). In group 1, RV end-diastolic volume (RVEDV) was not different from normal in the total group and averaged 93 +/- 4% (SEM) of normal. In patients with hemoglobin (Hgb) greater than or equal to 16 g%, however, this variable was significantly (P = 0.044) less than normal. Right ventricular ejection fraction was normal and RV systolic index was significantly (P less than 0.001) reduced, averaging 3.35 +/- 0.18 (SEM) L/min/m2. Left ventricular volume variables in this group were not significantly different from RV volume variables. In group 2, RVEDV in patients with Hgb greater than or equal to 16 g% was significantly (P = 0.037) less than normal, but was normal in patients with Hgb less than 16 g%. Right ventricular ejection fraction averaged 0.52 +/- 0.03 in this group and was significantly (P less than 0.001) less than normal. Right ventricular systolic index (RVSI) averaged 3.51 +/- 0.24 L/min/m2 and was significantly (P = 0.009) less than normal. RVSI in patients with Hgb less than 16 g% averaged 3.90 +/- 0.31 and was not different from normal. In contrast, this variable in patients with Hgb greater than or equal to 16 g% averaged 3.21 +/- 0.34 and was significantly (P = 0.005) less than normal. Left ventricular end-diastolic volume (LVEDV) and LV systolic output in group 2 were significantly higher than RVEDV and RV systolic output. Right ventricular and LV ejection fractions in group 2 were not different. The relatively decreased ejection fraction fraction in tetralogy patients, as compared with patients with valvular pulmonic stenosis and similar volumes and pressures, suggests that the decreased ejection fraction was not due to decreased preload or increased afterload and might be due to impaired ventricular function secondary to chronic hypoxia. Early corrective surgery in these patients might reverse this process. However, patients with severe tetralogy who have small ventricular volume and reduced output might benefit from shunt procedure rather than complete correction.

Adolescent↗
PubMed1976

Right and left ventricular volume characteristics in children with pulmonary stenosis and intact ventricular septum.

Right (RV) and left ventricular (LV) volume variables were calculated in 27 patients with pulmonary stenosis (PS) during routine cardiac catheterization. These included 21 patients with isolated PS (group I) and seven studies in six patients (group II) with PS and right-to-left atrial shunt. Right and left ventricular volumes were calculated according to Simpson's rule and the area length methods respectively. In group I, right ventricular end-diastolic volume (RVEDV) was not different from normal, RVEF (0.70 +/- 0.02) was significantly higher than normal, and right ventricular stroke index (RVSI) (4.36/L/min/M2 +/- 0.23) was normal. The RVEDV/LVEDV ratio was significantly less than normal (P=0.001). Multiple regression analysis indicated that RVEDV (% of normal) decreased with both age and severity of RV outflow obstruction (r=0.77). In group II, RVEDV and RVSI were both less than normal (P less than 0.001), while RVEF was normal. LVEDV in the group was slightly higher than normal (P=0.026) while LVEF was less than normal (P=0.027) and resulted in normal LVSI. The data suggest that RV and LV function in children with isolated PS are normal, and that knowledge of the RV volume variables is not essential for the management of these patients. In contrast, hearts of patients with PS and right-to-left interatrial shunt have evidence that suggest depressed ventricular function, and the quantitation of RV volume may be helpful in the management of these patients.

Adolescent↗
PubMed1976

The effect of left ventricular pressure or volume overload on ventricular dimension in children. Left ventricular volume determination from one or two ventricular dimensions.

The effect of pressure or volume overload on the geometry of the left ventricle (LV) was determined in order to examine the feasibility and accuracy of LV volume determinations from one minor axis or two dimensions (one minor axis and the longest length). The longest length (LL) and minor axis (MA) in both the anteroposterior (AP) view and lateral (LAT) view were determined from the LV cine silhouette in patients with normal LV volume and pressure (group 1), LV pressure (LVP) overload group (LVP greater than 140 mm Hg, group 2), and LV volume overload group (LV end-diastolic volume greater than 124% of normal, group 3). The ratio of the MA to the LL, which represents the spherical configuration of the LV, was less than "normal" in group 2, and higher than "normal" in group 3. In all groups the LV was less spherical at end-systole than at end-diastole. Additionally, the (MA)3 had a different relationship to true LV volume (biplane LV volume) in the three groups and from diastole to systole in each group. Left ventricular volume calculation from one minor axis was associated with a large error. In contrast, left ventricular volume can be accurately determined from two ventricular dimensions using either the anteroposterior or lateral ventricular image (r larger than or equal to 0.97).

Adolescent↗
PubMedDate not supplied

Spine fusion for discogenic low back pain: outcomes in patients treated with or without pulsed electromagnetic field stimulation.

Sixty-one randomly selected patients who underwent lumbar fusion surgeries for discogenic low back pain between 1987 and 1994 were retrospectively studied. All patients had failed to respond to preoperative conservative treatments. Forty-two patients received adjunctive therapy with pulsed electromagnetic field (PEMF) stimulation, and 19 patients received no electrical stimulation of any kind. Average follow-up time was 15.6 months postoperatively. Fusion succeeded in 97.6% of the PEMF group and in 52.6% of the unstimulated group (P < .001). The observed agreement between clinical and radiographic outcome was 75%. The use of PEMF stimulation enhances bony bridging in lumbar spinal fusions. Successful fusion underlies a good clinical outcome in patients with discogenic low back pain.

Adult↗
PubMedDate not supplied

Primary squamous-cell carcinoma of the breast. Diagnosis by fine needle aspiration cytology.

A primary squamous-cell carcinoma of the breast was evaluated by fine needle aspiration cytology in a 41-year-old female. The subsequent mastectomy specimen contained a well-differentiated keratinizing squamous-cell carcinoma. On electron microscopic evaluation, the tumor cells contained well-formed desmosomes and prominent bundles of tonofilaments, typical of squamous-cell carcinoma in other organs. Thorough evaluation of the patient did not reveal squamous-cell carcinoma elsewhere.

Adult↗