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Biomedical subjects

R Waldron

Publications and source records attributed to R Waldron.

At least 19 recordsLinked to original sources
PubMed1992

Mechanism of sphincter impairment following low anterior resection.

It has been postulated that reduction in anal resting pressure following low anterior resection is due to intraoperative injury to the internal anal sphincter during transanal passage of the stapling device or damage to its nerve supply in the course of rectal mobilization. The aim of this study was to assess the relative importance of either mechanism. Fourteen dogs had a standard segment of colon and distal rectum excised. Colorectal reconstruction was performed using either a low stapled EEA (U.S. Surgical Corporation, Norwalk, CT) colorectal anastomosis (n = 7) or a handsewn anastomosis (n = 7). Anorectal manometry was performed preoperatively and again on the 10th postoperative day. Resting anal pressure was significantly reduced after EEA anastomosis (mean +/- SEM: before, 49 +/- 3 mm Hg; after, 20 +/- 4 mm Hg; P less than 0.001) and handsewn anastomosis (mean +/- SEM: before, 46 +/- 4 mm Hg; after, 35 +/- 4 mm Hg; P less than 0.01). Postoperative resting pressures were also significantly reduced (P less than 0.05) following EEA anastomosis when compared with the handsewn group. This study suggests that damage to the innervation of the internal anal sphincter during rectal mobilization and further direct injury to the sphincter during transanal instrumentation both contribute to the fall in anal resting pressure observed following low anterior resection.

Anal Canal↗
PubMed1992

An analysis of the diagnostic accuracy of endoscopic biopsy and cytology in the detection of oesophageal malignancy.

The role of combined cytohistological examination in the differentiation of benign from malignant oesophageal mucosal lesions was studied in 331 patients. Malignancy was confirmed by specimen histopathology in 58 patients. Both endoscopic biopsy and cytology were positive in 41 (71%) patients. Endoscopic biopsy alone suggested malignancy in 10 cases (17%) while cytology was positive after negative biopsy in seven (12%). Cytology yielded four false positive and 10 false negative results giving a sensitivity level of 81%, a specificity of 98% and a positive predictive value for oesophageal malignancy of 92%. Histology on the other hand yielded one false positive and seven false negative results providing a sensitivity of 87%, a specificity of 99% and a positive predictive value of 96%. No patients were left undiagnosed using both diagnostic modalities; cytology increased the diagnostic yield from 87% to 100%. Exfoliative cytology was most valuable in the diagnosis of tumours of the lower one-third of the oesophagus where seven of 31 malignancies (23%) were identified by this method alone (P less than 0.05). Neither the histological type of the tumour nor the morphological appearance was found significantly to affect the diagnostic yield (P greater than 0.05). We conclude that cytological examination should be standard practice in the investigation of oesophageal lesions.

Biopsy↗
PubMed1991

Starting laparoscopic cholecystectomy--the pig as a training model.

Laparoscopic cholecystectomy is a reality and units must convert from open to endoscopic technique. To this end we have used the pig, whose biliary anatomy resembles the human, as a laboratory in vivo training model. Laparoscopic cholecystectomy has been performed in 35 animals. Techniques of pneumoperitoneum, vision, manipulation, clipping, ligation, cutting, diathermy and gall bladder removal were quickly mastered. All surviving animals underwent postmortem examination after 4 weeks. Following this laboratory programme, laparoscopic cholecystectomy in the human was introduced and has been completed successfully in 70 cases.

Animals↗
PubMed1991

Familial infantile oesophageal achalasia.

Oesophageal achalasia is uncommon in children and in its familial form it is a rarity. The presentation and management of two male siblings who presented with oesophageal achalasia as infants are reported. A high degree of consanguinity in the parents of the children existed, suggesting autosomal recessive transmission.

Esophageal Achalasia↗
PubMed1989

Declining indications for abdominoperineal resection.

In 126 consecutive patients operated on for carcinoma of the lower two-thirds of the rectum, a consistent policy of sphincter preservation resulted in 100 (79 per cent) having anterior resection and 22 (17 per cent) abdominoperineal resection. Perioperative complications in the anterior resection group were: death (two patients), clinical leakage (three patients), pulmonary embolism (five patients), pelvic haematoma (one patient), small bowel obstruction (one patient) and wound sepsis (six patients). Of 55 patients who had a potentially curative anterior resection with follow-up of at least 2 years, one developed local recurrence. Five per cent of patients had significant continence problems. Low anterior resection for carcinoma is associated with low perioperative morbidity, satisfactory functional results and acceptable local recurrence rates.

Aged↗
PubMed1989

Primary gastric lymphoma: incidence and role of surgery.

The histological subgroups of primary gastric tumours presenting to one surgical unit over two successive six year periods were analysed and the therapeutic value of gastric resection assessed. An increased incidence of gastric lymphoma (13% relative to 5%) occurred in the second six year period. This increase could not be attributed to improved morphological or histochemical techniques. The diagnosis of lymphoma was confirmed preoperatively in 13 (94%) of the 14 patients by a combination of multiple endoscopic biopsies and brush cytology. Five of the six patients who underwent a potentially curative resection are tumour free at a mean follow-up of four years. Histological grading, whether high or low, had no bearing on survival. Gastric lymphoma is increasing in incidence and should be considered in the evaluation of gastric tumours as surgical resection at present offers the best prospect of long term survival.

Adenocarcinoma↗
PubMed1987

The use of monoclonal antibodies for the histopathological detection of mammary axillary micrometastases.

We have studied the clinical value of immunohistochemical techniques in detecting occult axillary metastases from breast carcinoma in forty patients, all of whom had been assessed as free of nodal metastases by routine histology 5 years earlier. The same sections were restained using monoclonal antibodies against Epithelial Membrane Antigen (EMA). In four patients, occult metastases were detected, giving an increase in diagnostic accuracy of 10%. At 5-year follow-up 12 (30%) patients had developed tumour recurrence, of whom three were detected on immunohistochemical testing, while the other nine patients were reported as free of nodal metastases on staining with Anti-EMA. We conclude that routine application of immunohistochemical staining would further increase the diagnostic yield of axillary metastases from breast carcinoma, but this increase would not be of significant clinical value.

Adult↗
PubMed1986

Teicoplanin, its pharmacokinetics, blister and peritoneal fluid penetration.

The pharmacokinetics of a 440 mg iv dose of teicoplanin were studied in six male volunteers. The levels of the compound were measured microbiologically in serum, blister fluid and urine. The mean serum level 0-5 h after injection was 44.6 mg 1(-1), falling to 3.6 mg 1(-1) at 49 h. The serum elimination half-life of teicoplanin when fitted to a two-compartment model was 34.2 h; a three-compartment model gave a longer half-life. The apparent distribution half-life was 1.5 h. Penetration into cantharides induced blister fluid was moderately fast, the mean maximum concentration (14.8 mg 1(-1)) occurring at 2.7 h, the mean percentage penetration being 77.4%. Urinary recovery of the drug was 48.3% by 96 h. The drug penetrated rapidly into the non-inflammed peritoneal fluid of 34 patients undergoing elective surgery. The percentage penetration being 40% within the first hour, and 94.6% over the period of the study.

Adult↗
PubMed1986

Technique and results of trans-scrotal operations for hydrocele and scrotal cysts.

Surgical procedures for scrotal hydroceles and cysts carry a significant morbidity rate from haematoma formation. Lord's transcrotal procedure involves minimal tissue dissection. The present series of 84 cases confirms Lord's original claims of a very low risk of haematoma with no recurrence. It is concluded that Lord's procedure is effective, simple, safe and economic.

Adult↗