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Biomedical subjects

R H Taylor

Publications and source records attributed to R H Taylor.

At least 37 records · Page 2Linked to original sources
PubMed1999

Postgastrectomy pancreatic malabsorption: is there a case for intervention?

More patients are surviving surgery for gastric carcinoma than ever before. The possible causes of malabsorption following total gastrectomy are multifactorial, and pancreatic insufficiency has been proposed as one mechanism. Other contributing factors include loss of gastric reservoir, rapid small bowel transit, small bowel bacterial overgrowth and the type of operation performed. Although pancreatic exocrine insufficiency has been demonstrated after gastrectomy, the key question remains whether pancreatic enzyme supplements offer any substantial clinical benefit to the patient. The evidence to date does not support the routine use of pancreatic enzyme supplementation after gastrectomy.

Bacteria↗
PubMed1998

Transanal local excision of selected low rectal cancers.

BACKGROUND: To determine if transanal local excision (TALE) of selected early low rectal cancer is an effective alternative to more radical resection and to determine the need for adjuvant radiotherapy in these patients. METHODS: A retrospective analysis of all 47 cases referred for consideration of radiotherapy after TALE for low rectal cancer. RESULTS: Indications for TALE were elective, 32; concurrent medical problems, 11; and refusal of radical resection, 4. Median follow-up was 52 months. Local recurrence occurred in 7 of 27 T1 cases, 5 of 17 T2, and 2 of 3 T3. Three of 23 irradiated patients developed local recurrence, compared with 11 of 24 unirradiated (P = 0.023). Of 28 cases with favorable histological features, 1 of 13 irradiated patients developed local recurrence, compared with 4 of 16 unirradiated (P = 0.22). Seven patients had salvage resection, and 3 of these are alive with no evidence of disease at 21, 39, and 71 months postsalvage. Recurrence-free survival at 5 years was 81 % in the irradiated patients and 52% in the unirradiated (P = 0.025). CONCLUSIONS: Transanal local excision of selected low rectal cancers, combined with adjuvant radiotherapy, results in a low recurrence rate and is, therefore, an effective alternative to more radical resection.

Aged↗
PubMed1998

Ophthalmic abnormalities in homocystinuria: the value of screening.

PURPOSE: Homocystinuria, a genetic metabolic abnormality, eventually causes a variety of ocular and other pathologies if not treated. To evaluate the results of screening newborns for homocystinuria, we compared ophthalmic outcomes for two groups of homocystinuria patients who had been diagnosed either at birth or later than 6 weeks. METHODS AND RESULTS: Nineteen patients had been screened and diagnosed shortly after birth, with treatment instigated before 6 weeks of age (mean follow-up and age 10.8 years; median 11 years). Eight of 17 were myopic; 13 of 15 had good vision in both eyes; one had lens subluxation. The second group of 17 patients were diagnosed later than 6 weeks, often (12 patients) because of ocular problems (mean follow-up 8.3 years; mean age 19.4 years; median age 16 years). Visual function varied from 6/6 (4 patients) to less than 6/36 (4 patients); 3 eyes had no perception of light. Thirteen patients had lens subluxation or dislocation. CONCLUSION: Early diagnosis and treatment of homocystinuria is advantageous.

Adolescent↗
PubMed1998

Anatomy-based registration of CT-scan and intraoperative X-ray images for guiding a surgical robot.

We describe new methods for rigid registration of a preoperative computed tomography (CT)-scan image to a set of intraoperative X-ray fluoroscopic images, for guiding a surgical robot to its trajectory planned from CT. Our goal is to perform the registration, i.e., compute a rotation and translation of one data set with respect to the other to within a prescribed accuracy, based upon bony anatomy only, without external fiducial markers. With respect to previous approaches, the following aspects are new: 1) we correct the geometric distortion in fluoroscopic images and calibrate them directly with respect to the robot by affixing to it a new calibration device designed as a radiolucent rod with embedded metallic markers, and by moving the device along two planes, while radiographs are being acquired at regular intervals; 2) the registration uses an algorithm for computing the best transformation between a set of lines in three space, the (intraoperative) X-ray paths, and a set of points on the surface of the bone (imaged preoperatively), in a statistically robust fashion, using the Cayley parameterization of a rotation; and 3) to find corresponding sets of points to the X-ray paths on the surfaces, our new approach consists of extracting the surface apparent contours for a given viewpoint, as a set of closed three-dimensional nonplanar curves, before registering the apparent contours to X-ray paths. Aside from algorithms, there are a number of major technical difficulties associated with engineering a clinically viable system using anatomy and image-based registration. To detect and solve them, we have so far conducted two experiments with the surgical robot in an operating room (OR), using CT and fluoroscopic image data of a cadaver bone, and attempting to faithfully simulate clinical conditions. Such experiments indicate that intraoperative X-ray-based registration is a promising alternative to marker-based registration for clinical use with our proposed method.

Arthroplasty, Replacement, Hip↗
PubMed1997

Aplasia of the inferior rectus muscle. A case report and review of the literature.

PURPOSE: The authors describe the clinical findings, results of preoperative radiologic studies, and results of surgery in a boy with congenital unilateral inferior rectus aplasia. METHODS: A 2-year-old boy is described who presented with a significant anomalous head posture, a large incomitant vertical deviation with marked deficit of depression of the left eye, and positive head-tilt test results. Preoperative magnetic resonance imaging (MRI) defined an absent inferior rectus muscle; computed tomography showed no evidence of a craniofacial syndrome. Full tendon inferior transposition of the horizontal rectus muscles was carried out on the affected eye. RESULTS: The compensatory head position was eliminated. The infraduction improved. The patient had a small left hypotropia after the healing phase. CONCLUSIONS: To the authors' knowledge, this case is the first that used MRI to confirm preoperatively the isolated absence of an inferior rectus muscle. The MRI allowed effective surgical planning to correct the congenital abnormality.

Child, Preschool↗
PubMed1997

Diabetic eye disease: a natural history study.

In previous studies on diabetic retinopathy it has not been possible to relate risk factors to reduced vision because of the influence of vision-preserving treatment. Demographic data, cardiovascular risk factors and ocular features from the diabetic population of the Seychelles are described. Diabetic retinopathy in this population had not been modified by laser treatment. The population described consists of entirely type 2, maturity onset diabetics. Using a multivariate logistic regression model, the risk factors were deduced for three outcome variables: (1) reduced vision, defined as 6/36 or worse in both eyes; (2) the presence of diabetic retinopathy; and (3) the presence of maculopathy, preproliferative and proliferative retinopathy, grouped as severe retinopathy. Insulin treatment was associated with all outcome variables, duration from diagnosis of diabetes with retinopathy of all forms, and increasing age with reduced vision and severe retinopathy. Hypertensive diabetic patients were twice as likely to have reduced vision as compared with non-hypertensive diabetic individuals.

Adult↗
PubMed1997

Oesophageal ECG in a child for burns surgery.

Continuous monitoring of heart rate and rhythm are regarded as minimal standards of monitoring during anaesthesia. However, when the thoracic area is exposed for surgery as for debridement of burns and split skin grafting then placement of surface electrodes for electrocardiographic (ECG) monitoring is not possible. We report the intraoperative use of an old technique, oesophageal ECG (OesECG) in a child presenting for major burns surgery. The positioning of the probe, electrical safety and P-QRS morphology, are discussed.

Burns↗
PubMed1997

A robotic system for percutaneous renal access.

PURPOSE: Percutaneous renal access can be challenging, particularly when the collecting system is not distended. Precise entry into a selected calyx facilitates subsequent percutaneous manipulations, but this skill requires extensive experience. In an attempt to improve accuracy while decreasing technical challenges, we developed a robotic system that automates the task of fluoroscopic image-guided percutaneous needle placement. MATERIALS AND METHODS: The prototype system consisted of a three degree-of-freedom robot with a needle injector end-effector. Imaging was provided by a biplanar fluoroscope. After correction of image distortion and fluoroscope calibration, robot to image-space registration was completed. To validate the system's ability to insert a needle into a calyx, ex vivo porcine kidneys suspended in agarose gel and distended with iodinated contrast solution were used as a model. In situ renal access tests with three 20 kg. pigs were performed. Access was confirmed by passing a flexible wire or aspirating iodinated contrast from the collecting system. RESULTS: The diameter of target calyces ranged from 3 to 7 mm. The in vitro accuracy of final needle tip positioning was 0.43 mm. In the ex vivo model, successful "one stick" access occurred on 10 of 12 attempts (83%). In situ access on the first attempt was successful for 6 of 12 target calyces (50%). Needle or tissue deflection accounted for each failure. CONCLUSION: The feasibility of a robotic system to assist in the percutaneous access of small and delicate renal calyces has been demonstrated. Additional work in reducing procedural steps and correcting for tissue deflection during needle passage is necessary to improve accuracy and to allow for clinical application.

Animals↗
PubMed1996

Endometrial ablation with the combined Nd:YAG laser-rollerball.

Endometrial ablation, an effective treatment for intractable uterine bleeding, can be performed with hysteroscopic rollerball coagulation, neodymium:yttrium-aluminum-garnet (Nd:YAG) laser, and endomyometrial resection techniques. Between November 1990 and January 1995, 49 women underwent ablation with the Nd:YAG laser and a nontouch technique on the ostia, uterine fundus, and upper one-third to one-half of the posterior uterine wall, in combination with rollerball coagulation over the entire endometrial surface after 60-W Nd:YAG application. The power source of the rollerball was set at 80 W of pure coagulation current. Each patient was pretreated with a gonadotropin-releasing hormone agonist or an antiestrogenic compound. The complications were one uterine perforation with a dilator with no sequelae, and one severe infection requiring hysterectomy. There were no failures. Of the 48 women available to follow-up, amenorrhea was achieved in 43 (90%). Two continued to spot very slightly on occasion, but did not require minipads. Three women had light flow requiring one to two tampons for 1 to 4 days every month. The technique continues to provide a very high rate of complete amenorrhea.

Adult↗
PubMed1995

Postoperative emesis following otoplasty in children.

Sixty unpremedicated children aged between 3 and 14 years, scheduled for otoplasty, were randomly divided into one of three groups to receive either ondansetron 0.1 mg.kg-1, droperidol 75 micrograms.kg-1, or placebo at induction of anaesthesia. All patients received a standard general anaesthetic using thiopentone, atracurium and halothane. Opioid analgesia was avoided intra-operatively and infiltration with local anaesthetic was used prior to the start of surgery. Children who received ondansetron were less likely to vomit (15%) than those who received either droperidol (40%) or placebo (60%) (p < 0.01). This group also tolerated oral ingestion of fluids and solids earlier than those who received either droperidol or placebo (p < 0.001). There was no difference between the placebo or droperidol group in the incidence of vomiting or time to ingestion of oral fluids and meals. Three patients in the ondansetron group had a self-terminating nodal rhythm which was not associated with any haemodynamic disturbances. Postoperatively there were no untoward incidents in any of the groups and all patients were discharged home the day after surgery.

Adolescent↗
PubMed1995

The effect of a combination of rectal diclofenac and caudal bupivacaine on postoperative analgesia in children.

Both caudal anaesthesia and non-steroidal anti-inflammatory drugs have been used in the management of postoperative pain in children. The aim of the present study was to evaluate the combination of caudal analgesia and rectally administered diclofenac in the treatment of pain following minor surgery in children. Thirty-nine, ASA grade 1 or 2, children undergoing inguinal or penoscrotal surgery were randomly assigned to receive either a caudal block using 0.125% bupivacaine with adrenaline or a similar caudal block in combination with rectally administered diclofenac 1 mg.kg-1. Children given a caudal block alone were more likely to need analgesia in the first 24 h postoperatively. It would appear that the combination of a caudal block and rectal diclofenac in children undergoing minor lower abdominal surgery reduces the need for subsequent analgesia.

Administration, Rectal↗
PubMed1994

Profile of colorectal cancer at a community hospital with a multiethnic population.

A retrospective 10-year review of all (311) new cases of colorectal cancer at a community hospital serving a multiethnic urban population was carried out in order to study characteristics of the disease other than incidence and mortality rates. There was a striking similarity despite ethnic differences in most characteristics. The only differences between ethnic groups seen were anatomic distribution of cancer in the colon (statistically significant) and male-to-female ratio of colon cancer (apparent but not statistically significant). Characteristics are classified into three types: (1) Not influenced by ethnicity or by environment: Dukes' stage at presentation, colon-to-rectum ratio, histology, length of hospital stay, survival; (2) Possibly influenced by environment. mean age, male-to-female ratio, presence of synchronous polyps, duration of symptoms; (3) Influenced by ethnicity: anatomic distribution of cancer in the colon.

Aged↗
PubMed1994

Simultaneous two level oesophageal pH monitoring in healthy controls and patients with oesophagitis: comparison between two positions.

For oesophageal pH monitoring, the pH probe is usually positioned 5 cm above the lower oesophageal sphincter (LOS). This is by convention, and has not been compared with other positions in its ability to discriminate between physiological and abnormal acid reflux. Using simultaneous two level 24 hour pH monitoring (5 and 10 cm above manometrically determined LOS) in 31 controls and 51 patients with reflux oesophagitis, the significance of the precise position of the probe in the oesophagus was examined. Secondly, this study compared the discrimination between the two groups achieved at the two levels. Patients had greater acid exposure than controls at both levels. In controls, acid exposure was greater at distal than at the proximal level except the supine acid exposure, which was similar at both levels. In patients, acid exposure was greater at the distal level for all variables (median % of total time pH < 4 = 11.7 v 7.6; p = 0.001). There was excellent correlation between the two levels for all variables in controls (r = 0.883, 0.935, 0.813, and p < 0.001 for percentage of time pH < 4 for total, supine, and upright times) as well as in patients (r = 0.848, 0.848, 0.779, and p < 0.001). On discriminant and receiver operating characteristic analysis, pH threshold 4 seemed as good as or better than other pH thresholds in discriminating between controls and patients. The percentage of total time pH below 4 seemed to discriminate as well or better than other variables at both levels. The distal level (5 cm above LOS) provided slightly better discrimination than proximal level (10 cm) (percentage of subjects correctly classified=81.7 v 75.6). The critical factor for the reliability of the test is not the precise position of the pH probe relative to the LOS, but that the same position is consistently used in patients and controls.

Adult↗