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Biomedical subjects

R C Russell

Publications and source records attributed to R C Russell.

At least 19 recordsLinked to original sources

Strain-gauge evaluation of lunate unloading procedures.

A biomechanical study was undertaken to determine which procedure(s) most effectively relieve load from the lunate. Strain gauges were mounted on the lunates of 20 preserved cadaveric limbs. Three types of procedures were performed: scaphotrapeziotrapezoid arthrodesis, capitohamate arthrodesis, and ulnar lengthening. Load testing was performed both before and after the simulated fusions and ulnar lengthenings. Ulnar lengthening of 3 mm was the most effective method of lunate strain reduction. Capitohamate arthrodesis decreased compressive strain but increased shear strain. Scaphotrapeziotrapezoid fusion significantly increased both compressive and shear strain in the lunate. Of the three procedures that were tested, ulnar lengthening to create a neutral variance is the most reliable means of unloading the lunate.

Analysis of Variance

Evaluation and management of upper extremity neuropathies in Charcot-Marie-Tooth disease.

The evaluation and treatment of five patients with upper extremity neuropathies secondary to Charcot-Marie-Tooth disease were reviewed with emphasis on age at onset of Charcot-Marie-Tooth disease and upper extremity deformities, clinical findings, signs of associated nerve compression, and outcome of surgical treatment. The onset of the disease generally occurred in the first or second decade of life. The onset of upper extremity symptoms lagged behind by an average of 8 years. All patients had intrinsic minus hands with decreased sensibility. Three of five patients had clinical or electrophysiologic evidence of associated nerve compression syndromes. Treatment with standard tendon transfers, nerve compression releases, soft tissue releases, and joint fusions resulted in subjectively improved function in three of four patients undergoing reconstruction. Release of six compression neuropathies in one patient provided excellent pain relief, but the underlying neuropathy progressed. Pessimism regarding reconstructive surgery in the patient with upper extremity neuropathies secondary to Charcot-Marie-Tooth disease is unwarranted.

Adult

The effect of hyperbaric oxygen on reperfusion of ischemic axial skin flaps: a laser Doppler analysis.

This study evaluates the microvascular reperfusion of ischemic skin flaps with and without acute hyperbaric oxygen (HBO) treatment. Thirty-two axial pattern epigastric skin flaps (3 x 6 cm) in male Wistar rats were subjected to 8 hours of global ischemia by pedicle clamp occlusion. The rats were divided into the following control and two experimental groups: Control (n = 12) with ischemia, no HBO; Group 1 (n = 11) with HBO treatment (three 1.75-hour dives, 2.5 absolute atm, 100% O2) during ischemia; and Group 2 (n = 9) with HBO treatment (two 1.75-hour dives) immediately after ischemia. Laser Doppler flows were recorded in two distal standardized flap locations at 0.5, 2, 4, and 18 hours after reperfusion in control rats and Group 1 rats and at 18 hours only in Group 2 rats, using a Med-Pacific 6000 laser Doppler unit. Mean distal flap laser Doppler flows (mV) were Control: 0.5 hours = 23.2 +/- 11.9, 2 hours = 52.8 +/- 27.3, 4 hours = 53.6 +/- 32.1, 18 hours = 40.2 +/- 36.2; Group 1: 0.5 hours = 71.8 +/- 30.9 (p less than 0.05 vs. control), 2 hours = 74.3 +/- 27.3, 4 hours = 67.4 +/- 20.6, 18 hours = 79.1 +/- 40.3 (p less than 0.05 vs. control); and Group 2: 18 hours = 90.3 +/- 47.9 (p less than 0.05 vs. control). It is concluded that acute HBO treatment of ischemic rat skin flaps improves distal microvascular perfusion as measured by laser Doppler flowmetry. This effect is observed for HBO treatment given either during or immediately after prolonged global ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

The susceptibility of the mosquitoes Aedes notoscriptus and Culex annulirostris to infection with dog heartworm Dirofilaria immitis and their vector efficiency.

The mosquitoes Aedes notoscriptus (Skuse) and Culex annulirostris Skuse were fed on a dog infected with Dirofilaria immitis (Leidy) and a blood parasite count of approximately 5000 microfilaria per ml. Cx annulirostris ingested almost 4 times as much blood and almost 4 times as many microfilariae as Ae.notoscriptus (mean 26.0 compared to 6.6). Attrition of the filarial numbers occurred primarily within the midgut during the first 24 h following ingestion and was greater in Cx annulirostris than Ae.notoscriptus. Aedes notoscriptus sustained development of almost 8 times as many third-stage infective larvae as Cx annulirostris (mean of 3.8 compared to 0.5), and thus had a vector efficiency index of 57.6 compared to 1.9 for Cx annulirostris. In a series of investigations Ae.notoscriptus has now been shown to be an important vector for dog heartworm in southern Australia and may be a significant factor in the apparent burgeoning of the disease.

Aedes

Minimal change chronic pancreatitis.

In patients with severe abdominal pain, of pancreatic origin, there are a few with minimal or equivocal findings on pancreatic investigation and in whom the aetiology of their pancreatic disease is elusive. The findings and outcome in 16 of these patients (four men and 12 women) who underwent resection are reported. Pancreatic imaging showed minimal or equivocal findings in all 16; pancreas divisum was present in five. All were managed conservatively at first but resection was required for progression of symptoms. A drainage procedure was performed initially in five patients but relief of pain was at best transitory before further surgery was required. Partial resection was needed in 12, of whom eight required subsequent completion pancreatectomy and four had a one stage total resection. Nine patients are currently pain free after resection or are very much improved, while six are no better and one patient has died from an unrelated cause. Histology of resected specimens showed chronic inflammatory changes accompanied by subtle non-inflammatory changes in all but one. These changes include duct proliferation, duct complex formation, adenomatous nodules, and acinar cell atrophy, the significance of which is unclear. These findings suggest a syndrome of minimal macroscopic and radiological change chronic pancreatitis with pain as its chief clinical feature and a distinct histology, the aetiology of which is unclear. It seems that there is a distinct syndrome of minimal change pancreatitis, among the group of patients which presents with the clinical features of chronic pancreatitis.

Adolescent

Selection, management, and early outcome of 113 patients with symptomatic gall stones treated by percutaneous cholecystolithotomy.

Between January 1988 and December 1990, 283 patients with symptomatic gall stones were referred for non-operative treatment. After ultrasound scanning including a functional assessment, 220 (78%) patients were found to be suitable for percutaneous cholecystolithotomy. Of these, 113 underwent the procedure including 10 in whom extracorporeal shock-wave lithotripsy or methyl tert-butyl ether therapy had failed. Forty four patients underwent extracorporeal shockwave lithotripsy, methyl tert-butyl ether therapy or rotary lithotripsy, 46 chose laparoscopic cholecystectomy or minicholecystectomy and 27 declined treatment. Percutaneous cholecystolithotomy was successfully performed in 100 patients. Thirty four patients were a high operative risk and 14 presented with an acute complication of gall stone disease. Complications developed in 15 patients, all of whom were managed conservatively and most occurred during development of the technique. Outcome has been assessed clinically and by ultrasound scanning in 92 patients with a median follow up period of 14 months (six to 37 months). Seventy nine per cent were completely cured of their symptoms. Ninety three per cent of gall bladders were shown to be functioning and nine (9.8%) contained stones, although five of these are believed to have developed from residual fragments. Percutaneous cholecystolithotomy is a safe, non-operative treatment for symptomatic gall stones and enabled the patient to fully recover within two to three weeks; it has a definite role in the management of the elderly and high risk patient but its use for the treatment of other groups is likely to remain controversial.

Adolescent

US-guided percutaneous pancreatography: an essential tool for imaging pancreatitis.

The pancreatic duct can be opacified when contrast material is injected through a fine needle percutaneously placed under ultrasound (US) guidance. Percutaneous pancreatography was performed in 63 patients with chronic pancreatitis diagnosed at US or computed tomography (CT). In 52 of these patients, endoscopic retrograde pancreatography (ERP) was unsuccessful or did not enable complete visualization of the duct. The percutaneous pancreatograms and other relevant images of these patients were retrospectively reviewed. Percutaneous pancreatography was successful in 54 patients (86%), in whom it clearly mapped the full ductal anatomy, depicted the relationship between cavities seen at US or CT and the duct, and allowed assessment of duct drainage after antegrade injection of contrast material. This information was not provided by other modalities. Percutaneous pancreatography is a valuable complement to CT, US, and ERP for imaging chronic pancreatitis.

Cholangiopancreatography, Endoscopic Retrograde

Percutaneous techniques for the management of symptomatic gallbladder stones.

Several non-operative treatments for the management of patients with symptomatic gallstones have been developed with the purpose of avoiding the considerable morbidity associated with open cholecystectomy. Minimally invasive techniques utilizing direct percutaneous puncture of the gallbladder are being increasingly used for the diagnosis and treatment of gallbladder disease and are the subject of this review. With the emergence of laparoscopic cholecystectomy the role of these techniques is less certain but they are likely to continue to be important in the management of high risk, elderly or medically unfit patients.

Acute Disease

Can cholangiography be safely abandoned in laparoscopic cholecystectomy?

The introduction of laparoscopic cholecystectomy, improvements in ultrasound technology and the success of endoscopic sphincterotomy have raised new questions regarding the role of intraoperative cholangiography. Our aim was to analyse the ability of preoperative clinical and ultrasound assessments to detect common duct stones in 86 patients with symptomatic cholecystolithiasis who then underwent cholangiography after percutaneous cholecystolithotomy. Six patients gave a history suggestive of common duct stones (either jaundice, cholangitis or pancreatitis). Ultrasound showed a dilated common duct in four patients (normal < 6 mm), and one of these had a stone demonstrated in the duct. The latter patient and one other with a dilated common duct had stones on cholangiography (which were extracted at ERCP), no stones were demonstrated in the other two. Ultrasound correctly identified common duct stones in two and excluded common duct stones in four others with a history suggesting the presence of stones. For patients undergoing laparoscopic cholecystectomy we would advocate the use of preoperative ultrasound instead of intraoperative cholangiography, and that endoscopic retrograde cholangiopancreatography is performed in the small number of patients shown to have a dilated duct or common duct stone.

Cholangiography

New trends in gallstone management.

Many new therapies for the management of gallstone disease have been pioneered in the past decade. The object of this review is to equip the surgeon with the answers to all of the questions a patient will ask about gallstone therapy; the review is therefore didactic as well as comprehensive.

Bile Acids and Salts

Gallbladder sepsis after stent insertion for bile duct obstruction: management by percutaneous cholecystostomy.

Of 364 patients undergoing insertion of a biliary endoprosthesis in 1989, six (1.6 per cent) developed gallbladder sepsis. Three patients had cholangiocarcinoma, two had carcinoma of the pancreas and one had a benign biliary stricture. Two of the five patients with malignancy had gallbladder stones, and the patient with a benign stricture developed stones after 3 years of stenting. Three patients developed gallbladder sepsis early after endoprosthesis insertion (less than 6 days), while in the other three it occurred late (greater than 6 months). All six patients failed to respond to antibiotics and were successfully managed by percutaneous cholecystostomy; the patient with a benign biliary stricture also had cholecystolithotomy. The gallbladder drainage tubes were removed or became dislodged at intervals varying from 2 weeks to 6 months without complications. Percutaneous cholecystostomy is the treatment of choice for gallbladder sepsis unresponsive to antibiotics in patients with a biliary endoprosthesis in situ.

Adenoma, Bile Duct

Detection of foreign bodies in the hand.

Fresh cadaver hands were used to compare the ability of routine x-ray, xeroradiography, computerized tomography, and magnetic resonance imaging to identify a variety of foreign bodies including glass, gravel, plastic, and wood in the soft tissue of the hand. All types of glass were easily seen by all imaging methods. Gravel foreign bodies were visible with all methods except magnetic resonance imaging where ferromagnetic streak artifacts obscured visualization. Plastic, although not seen by routine x-ray or xeroradiography, was faintly seen by computed tomography, and easily detected by magnetic resonance imaging. Wooden foreign bodies, especially when wet, were seen only by computed tomography and magnetic resonance imaging. Xeroradiography had no benefit over plain films in identifying foreign bodies and should be discarded in favor of computed tomography or magnetic resonance imaging when plain films are unrevealing. A practical guide for identifying foreign bodies in the soft tissues of the hand is presented.

Aged