Arthroscopic excision of the os trigonum: a new technique with preliminary clinical results

Open excision of a painful os trigonum can be associated with prolonged recovery. An arthroscopic technique has been developed to decrease scarring, diminish surgical morbidity, and promote a faster recovery. Eleven patients were retrospectively evaluated after removal of the os trigonum after a mean follow-up of 35 months. Small joint arthroscopy equipment was utilized in a supine position with a distraction device. Average patient scores improved on the AOFAS Ankle/Hindfoot Scale from 45 to 86 points. All patients went home the same day, and no complications occurred during the procedure. All patients reached maximum recovery level within the first 3 months after surgery. Arthroscopic excision of a painful os trigonum yields good results with minimal surgical morbidity and shorter recovery time.     

HSP 70 synthesis in clinical hyperthermia patients: preliminary results of a new technique

PURPOSE: Although thermotolerance may be an important variable in clinical hyperthermia, few means have been described to measure its effect or duration in the clinical setting. This study was undertaken to determine if heat shock protein 70 could be used as an assay to predict the presence of retained thermotolerance in human tumors. METHODS AND MATERIALS: Tissue samples were obtained from patients undergoing hyperthermia and assayed for heat shock protein 70 synthesis. Eight patients having advanced, persistent, or recurrent malignant tumors had open-ended thermometry catheters placed into the lesion being heated. Through these catheters, tissue samples were obtained using a fine needle aspiration technique. Attempts were made to obtain samples before and after the first three heat treatments. Some samples were labeled immediately with radioactive methionine (35S) at 37 degrees C for 4-8 hr, others were given a test heat dose in vitro and then labeled. Protein synthesis profiles were analyzed by gel electrophoresis and autoradiography. RESULTS: Preliminary results show that it is possible to obtain tissue from hyperthermia patients in a safe and practical manner, that the rate of heat shock protein 70 synthesis can be measured in a variety of tumors, and that the persistence of thermotolerance in the clinical setting can be shown by the inability to reinduce heat shock protein 70 synthesis. CONCLUSION: The measurement of heat shock protein 70 using the described technique may provide an assay for retained thermotolerance in clinical hyperthermia. Technical difficulties which need to be addressed include obtaining sufficient tissue in all patients, confirming the presence of tumor in the obtained tissue, and obtaining tissue at more frequent intervals to best determine the kinetics of thermotolerance.     

Inguinal microsurgical varicocelectomy in the adolescent: technique and preliminary results

PURPOSE: In large series of adults microsurgical varicocelectomy has been associated with extremely high success rates, combined with minimal incidence of postoperative hydrocele. We report our initial experience of inguinal varicocelectomy using an intraoperative microscope in adolescents. MATERIALS AND METHODS: From 1994 to 1996, 32 adolescents (mean age 15.3 years) underwent inguinal microsurgical varicocelectomy. An operative microscope and Doppler probe were used during spermatic cord dissection to identify and preserve the testicular artery and lymphatics. RESULTS: All patients were available for followup, which ranged from 2 to 35 months (mean 20). There were no intraoperative complications. A temporary reactive hydrocele, which subsequently completely resolved, was observed in 1 patient. There were no palpable recurrent varicoceles. CONCLUSIONS: The operative microscope permits reliable identification of the testicular artery and lymphatics, as well as venous channels in adolescents. As a result, the postoperative development of hydrocele or recurrence of the varicocele may be prevented.     

Dual-phase spiral CT angiography with volumetric 3D rendering for preoperative liver transplant evaluation: preliminary observations

BACKGROUND: Although low arterial oxygen tension (Po2) has been claimed to occur in one to two thirds of patients with cirrhosis, hypoxaemia appears to be rare in clinical practice. AIMS: To assess the frequency of arterial hypoxaemia in cirrhosis in relation to clinical and haemodynamic characteristics. PATIENTS: One hundred and forty two patients with cirrhosis without significant hepatic encephalopathy (grades 0-I) (41 patients in Child class A, 57 in class B, and 44 in class C) and 21 patients with hepatic encephalopathy. RESULTS: Mean Po2 in kPa was 11.3 in Child class A, 10.8 in class B, 10.6 in class C, and 10.6 in patients with encephalopathy (p < 0.05). The fraction of patients with Po2 below the lower normal limit of 9.6 kPa was 10%, 28%, 25%, and 43%, respectively in class A, B, C, and in patients with encephalopathy (p < 0.05). Oxygen saturation (So2) in these groups was respectively: 96%, 96%, 96%, and 93% (NS). So2 was below the lower limit of 92% in 0%, 9%, 7%, and 24% (p < 0.05). In patients without hepatic encephalopathy, a multivariate regression analysis revealed that independent determinants of a low Po2 were a high arterial carbon dioxide tension, a low systemic vascular resistance, and a low indocyanine green clearance (p < 0.0001). CONCLUSION: The prevalence of arterial hypoxaemia in cirrhosis is about 22% in patients without encephalopathy, but it varies from 10-40% depending on the degree of hepatic dysfunction. Arterial hypoxaemia in patients with cirrhosis of differing severity seems lower than previously reported, and patients with severe arterial hypoxaemia are rare.     

Three-dimensional CT measurement of adult acetabular dysplasia: technique, preliminary results in normal subjects, and potential applications

OBJECTIVE: To assess a three-dimensional computed tomography (3DCT) technique for measurement of acetabular coverage in adults. DESIGN: We used 3DCT to define the geometric centre of the femoral head and to measure centre-edge angles (CEAs) at 10 degrees rotational increments around the acetabular rim. The means, ranges, standard deviations and 95% confidence intervals for the CEAs at the various rotational increments were determined. Inter- and intra-observer variability was measured. The normal values are compared with two example cases of acetabular dysplasia. PATIENTS: The normal hips of 15 subjects aged 1949 years (mean 34.2 years) were measured. RESULTS: The 3DCT measurements are reproducible (mean difference interobserver, 1.7 degrees - 7.9 degrees; mean difference intra-observer, 0.6 degrees-6.9 degrees). Mean normal CEA at the lateral rim was 33 degrees with a 95% confidence interval of 23 degrees - 43 degrees. Mean normal CEAs at 10 rotational increments from anterior to posterior rim were determined, and graphed as a 'normal curve'. CONCLUSION: This new 3DCT method of assessing acetabular dysplasia is simple, reproducible, and applicable to diagnosis, quantification and surgical planning for adult acetabular dysplasia patients.     

Coregistration imaging of the foot. A new localisation technique

We describe a new technique, known as coregistration imaging, which superimposes 99mTc isotope bone scans on to plain radiographs. We used the technique selectively in cases in which the nuclear medicine physician, who reported the isotope scan, had difficulty in localising the anatomical site of the abnormality. In the forefoot, coregistration of isotope scans did not help to localise pathology; the scan alone gave sufficient detail. In 17 patients with pain in the hind- and midfoot, isotope scanning identified eight sites of abnormality in those with normal radiographs. In those with more than one abnormality on plain radiographs the isotope scan eliminated 12 sites of suspicion. Coregistration of the images significantly increased the certainty of localisation of disease (p < 0.001). We recommend the selective use of coregistration scanning as a useful technique for investigating patients with pain in the foot and ankle.     

Method for segmenting chest CT image data using an anatomical model: preliminary results

We present an automated, knowledge-based method for segmenting chest computed tomography (CT) datasets. Anatomical knowledge including expected volume, shape, relative position, and X-ray attenuation of organs provides feature constraints that guide the segmentation process. Knowledge is represented at a high level using an explicit anatomical model. The model is stored in a frame-based semantic network and anatomical variability is incorporated using fuzzy sets. A blackboard architecture permits the data representation and processing algorithms in the model domain to be independent of those in the image domain. Knowledge-constrained segmentation routines extract contiguous three-dimensional (3-D) sets of voxels, and their feature-space representations are posted on the blackboard. An inference engine uses fuzzy logic to match image to model objects based on the feature constraints. Strict separation of model and image domains allows for systematic extension of the knowledge base. In preliminary experiments, the method has been applied to a small number of thoracic CT datasets. Based on subjective visual assessment by experienced thoracic radiologists, basic anatomic structures such as the lungs, central tracheobronchial tree, chest wall, and mediastinum were successfully segmented. To demonstrate the extensibility of the system, knowledge was added to represent the more complex anatomy of lung lesions in contact with vessels or the chest wall. Visual inspection of these segmented lesions was also favorable. These preliminary results suggest that use of expert knowledge provides an increased level of automation compared with low-level segmentation techniques. Moreover, the knowledge-based approach may better discriminate between structures of similar attenuation and anatomic contiguity. Further validation is required.     

Intravesical electromotive drug administration technique: preliminary results and side effects

PURPOSE: We performed intravesical electromotive drug administration (EMDA) for various bladder disorders during a 3-year period and assessed the technique, possible applications, complications and outcomes of this procedure. MATERIALS AND METHODS: Intravesical EMDA was performed with local anesthetics for transurethral surgery and in combination with dexamethasone for the treatment of noninfectious chronic cystitis (interstitial/radiation cystitis), with mitomycin C for recurrence prophylaxis of high risk superficial bladder cancer and with oxybutynin/bethanechol for the hyperreflexive/acontractile detrusor. A standardized power source and electrode catheter were used for 215 treatments in 84 patients. RESULTS: Transurethral bladder tumor resections were pain-free in 10 of 12 patients. Of the 25 patients with chronic noninfectious cystitis 15 were free of symptoms for a mean of 6.6 months, and there was a 73% increase in mean bladder capacity from 244 before to 421 cc after EMDA. Of the 16 patients with superficial bladder cancer 9 were free of recurrence for a mean of 14.1 months. In 10 of 14 patients with acontractile detrusors urodynamic examination showed detrusor contraction during EMDA of bethanechol. There were no contractions without electric current. EMDA of oxybutynin reduced detrusor hyperreflexia. A bladder ulcer was the single severe local complication and 4.6% of patients, mainly those with chronic cystitis, reported significant post-EMDA bladder/urethral pain. Minor side effects accounted for 23% of all treatments. No systemic side effects occurred. CONCLUSIONS: Intravesical EMDA is effective and innocuous. The therapeutic concept combines the advantages of increased drug administration without systemic side effects.     

Posterior sagittal resection for rectal aganglionosis: preliminary results of a new approach

BACKGROUND: There is no general agreement about how patients who have short-segment Hirschsprung's disease should be treated. METHODS: Ten patients with Hirschsprung's disease, seven with rectal and three with rectosigmoidal aganglionosis, were operated on through a posterior sagittal incision. In nine patients, a primary rectal resection and coloanal anastomosis was performed. In one patient, a longitudinal posterior myectomy of the rectum was performed as a primary procedure, but the procedure was eventually converted to a rectal resection and coloanal anastomosis through the same incision. RESULTS: One early and one late anastomotic complication occurred. Both were successfully treated with a temporary fecal diversion (left-sided colostomy for 6 to 8 weeks). The functional results as evaluated with anorectal manometry were similar to a group of Hirschsprung's patients treated with transabdominal pull-through resection and coloanal anastomosis. CONCLUSION: This approach might prove to be a useful alternative both to the transabdominal resection and the posterior longitudinal rectal myectomy in Hirschsprung's disease with rectal aganglionosis.     

Laparoscopic anterior gastroplasty. A preliminary report of a new technique

BACKGROUND: The treatment of the morbidly obese patient is difficult because compliance with dietary regimens is poor. As a result, most weight reduction programs fail very quickly. Surgical treatment, on the other hand, provides a reliable method for sustained weight reduction. The most frequently performed procedure has been the vertical banded gastroplasty. Adaptation of the standard open procedure to laparoscopic techniques has been technically difficult and imprecise. We have developed, in the laboratory, an anterior wall banded gastroplasty that can be performed precisely and reproducibly using laparoscopic techniques. METHODS: Five Yorkshire pigs were used in attempt to laparoscopically perform the standard vertical banded gastroplasty. The procedure was difficult and was associated with a risk of staple line leak and with bleeding along the lesser curvature of the stomach. Furthermore, a reproducible pouch of proper dimension could not be created reliably. Fifteen animals were then used to develop a new technique using a small gastric pouch based on the anterior gastric wall. RESULTS: A reproducible pouch, 4 cm in length, was created over an 18-Fr nasogastric tube. A standard polyproylene band of 5.2 cm in length was utilized at the gastric pouch outlet. CONCLUSIONS: This operation can be reproduced accurately and has not demonstrated any leaks on postmortem examination.     

High-resolution cross-sectional imaging of the gastrointestinal tract using optical coherence tomography: preliminary results

BACKGROUND: Optical coherence tomography (OCT) is a novel technique for noninvasive cross-sectional imaging with high spatial resolution (10 to 20 microm). OCT is similar to B-mode ultrasound except that it uses infrared light rather than ultrasound. We studied OCT imaging of the gastrointestinal (GI) tract in vitro to analyze the potential of this technique for endoscopic applications. METHODS: Human gastrointestinal tissues harvested from surgical resection and autopsy specimens were used. Specimens were imaged within 5 hours of resection or snap frozen in liquid nitrogen. After imaging, OCT scan locations were carefully marked using dye microinjections, fixed, and prepared for routine histologic processing. OCT images were then compared and correlated with the histologic sections. RESULTS: OCT images demonstrated clear delineation of the mucosa and submucosa in most specimens. Furthermore, microscopic structures such as crypts, blood vessels, or esophageal glands in the submucosa and lymphatic nodules were observed. CONCLUSIONS: The resolution of OCT images of GI wall is sufficient to delineate the microscopic structure of the mucosa and submucosa. Potentially, OCT would allow in vivo imaging at endoscopy of the microstructure of the mucosa and submucosa. This would be particularly useful in the detection and staging of small lesions such as early stage cancers.     

Ultrasound guided excisional biopsy of non-palpable breast lesions: technique and preliminary results

OBJECTIVE: To develop a simple and accurate technique of incisional biopsy under ultrasonographic guidance to aid the histological diagnosis of non-palpable lesions of the breast DESIGN: Open prospective study. SETTING: Teaching hospital, Italy. SUBJECTS: 35 patients who presented to this hospital with 42 non-palpable lesions diagnosed by echography or mammography during 18 month period 1995-1996. INTERVENTIONS: Creation of a pocket in the breast in which the transducer of the ultrasound scanner was inserted to guide the surgeon while an excision biopsy was taken. MAIN OUTCOME MEASURES: Histological diagnosis, and quality of scar. RESULTS: Mean (SD) diameter of the lesions was 11.6 (3.15) mm on the ultrasound scan, that of the biopsy specimens was 18.1 (5.82) mm, and that of the histological specimens 9.7 (3.52) mm. 29 lesions showed fibrocystic mastopathy with apocrine metaplasia, 10 fibroadenomas, 2 invasive ductal carcinoma, and 1 atypical duct hyperplasia. There were no unsightly scars. CONCLUSIONS: We have developed a simple and accurate technique for incisional biopsy under ultrasound control.     

Detection of hypervascular hepatocellular carcinoma by using spiral volumetric CT: comparison of US and MR imaging

BACKGROUND: Most hepatocellular carcinomas (HCCs) are hypervascular and arise in the liver with chronicity. Spiral volumetric CT (SVCT) is a new rapid-scan technique that offers whole-liver scanning during the arterial-dominant phase. The main aim of the present study is to evaluate the detectability of hypervascular HCC with SVCT as compared with ultrasonography (US) and magnetic resonance (MR) imaging. METHODS: Forty-three hypervascular HCCs in 512 patients with chronic liver disease were examined with US, precontrast SVCT, postcontrast SVCT during the arterial-dominant phase (CT-ADP) and during the equivalent-phase (CT-EP) noncontrast MR imaging and angiography including SVCT during arteriography and arterial portography. Angiographic and follow-up findings were used as the gold standard if the lesion was not confirmed histologically. RESULTS: The sensitivity was 61% with precontrast CT, 84% with CT-ADP, 58% with CT-EP, 70% with US, 72% with MR, and 95% with the combination of these five modalities. Five HCCs (12%) were detected with only CT-ADP. The vascularity of HCC was correctly evaluated as hypervascular in 38 nodules (88%) with the combination of precontrast CT and CT-ADP. CONCLUSIONS: We suggest that the combination of precontrast SVCT and CT-ADP is an essential modality to screen for HCC in patients with chronic liver disease. CT-EP did not contribute to the detection of hypervascular HCC.     

Gradient moment smoothing: a new flow compensation technique for multi-shot echo-planar imaging

This work identifies an additional source of phase error across ky in multi-shot echo-planar imaging resulting from flow or motion along the phase-encoding direction. A velocity-independent flow compensation technique, gradient moment smoothing, is presented that corrects this error by forcing the phase to have smooth quadratic behavior. The correction is implemented, without compromising scan time, by changing the first moment of a bipolar prephaser pulse on a shot-by-shot basis. In phantom and in vivo experiments, gradient moment smoothing effectively eliminates ghosting and signal loss due to phase-encoding flow. When used in conjunction with a "flyback" echo-planar readout, which compensates for flow in the frequency-encoding direction, gradient moment smoothing renders multi-shot echo-planar imaging relatively insensitive to in-plane flow. This can make multi-shot echo-planar imaging a viable technique for accurately imaging in-plane flow and may desensitize it to the otherwise serious problem of in-plane motion.     

Oligodendrogliomas. Part II: A new grading system based on morphological and imaging criteria

Myocardial perfusion scintigraphy is a noninvasive diagnostic method for the evaluation of patients with suspected or proven coronary artery disease (CAD). We utilized case-based reasoning (CBR) methods to develop the computer-based image interpretation system SCINA which automatically derives from a scintigraphic image data set an assessment concerning the presence of CAD. We compiled a case library of 100 patients who underwent both perfusion scintigraphy and coronary angiography to document or exclude the presence of CAD. The angiographic diagnosis of the retrieved nearest neighbor match of a scintigraphic input case was selected as the CBR diagnosis. We examined the effects of input data granularity, case indexing, similarity metric, and adaptation on the diagnostic accuracy of the CBR application SCINA. For the final prototype, sensitivity and specificity for detection of coronary heart disease were 98% and 70% suggesting that CBR systems may achieve a diagnostic accuracy that appears feasible for clinical use.     

A dental CT study for preoperative assessment of maxillary atrophy

According to a new technology in the planning of endo-osseous implantation, based on a new CT-software for evaluation of the bone structure of the jaws, anatomico-morphological changes after the loss of teeth are measured much more accurately than with conventional methods like the panoramic intraoral x-ray or conventional tomography. 30 mandibles and 22 maxillae of 36 patients were examined. Besides the topographic course of the mandibular canal and the location of the foramen mentale, the anatomic structures as the important aspects for planning endo-osseous implants are seen more accurately. It is now possible to recognise morphological changes with paraxial reconstructions in a very short time more clearly and precisely than with former techniques.