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Biomedical subjects

M A Jewett

Publications and source records attributed to M A Jewett.

At least 19 recordsLinked to original sources
PubMed1992

The use of an abdominal compression belt to reduce stone movement during extracorporeal shock wave lithotripsy.

We used an abdominal compression belt in 50 patients undergoing extracorporeal shock wave lithotripsy with the Siemens Lithostar lithotriptor to limit diaphragmatic excursion and, therefore, renal calculus movement. Stone movement was measured on the monitor with and without the compression belt. Abdominal compression was found to decrease the range of stone movement by an average of 32% (-4 to 63%). This technique was less effective in patients with limited chest expansion. Abdominal compression was also found to be useful during treatment of renal and upper ureteral stones in reducing overall patient movement. The decreased stone movement during extracorporeal shock wave lithotripsy with abdominal compression may increase stone fragmentation and may decrease the number of shocks per treatment.

Humans↗
PubMed1992

Potential for inter-observer and intra-observer variability in x-ray review to establish stone-free rates after lithotripsy.

The potential for variability among observers interpreting diagnostic tests is well known but has not been well established for radiological imaging of urolithiasis. We measured the inter-observer and intra-observer variability in the reporting of plain abdominal films and tomograms from patients who had undergone extracorporeal shock wave lithotripsy (ESWL). Unlabeled copies of the plain abdominal films and tomograms for 58 patients were individually submitted to 3 different radiologists. Selected films from 25 patients were resubmitted to the same radiologists. We found differences among radiologists reporting plain abdominal films alone 52% of the time and even by the same radiologist rereading the films 24% of the time. Tomograms alone decreased the uncertainty but differences still occurred among radiologists 24% of the time and with themselves 16% of the time. When plain abdominal films and tomograms were read together there were differences among radiologists 28% of the time and with themselves 7% of the time but these were usually minor. We concluded from this study that the plain abdominal film alone was frequently difficult to interpret, resulting in uncertainty about the presence or absence of residual stone fragments. Tomograms alone or a plain abdominal film plus tomograms is superior to a plain abdominal film alone. Finally, radiological assessment with all modalities probably overestimates stone-free rates after ESWL even without consideration of the potential for reporting variability among observers.

Humans↗
PubMed1992

Lithostar extracorporeal shock wave lithotripsy: the first 1,000 patients. Toronto Lithotripsy Associates.

To our knowledge this study of our first consecutive 1,000 patients treated with the Siemens Lithostar device is the largest prospective series reported to date. Treatment results were determined at 3, 12 and 24 months after completion of therapy. The results at 3 months are presented. Complete followup data were available on 801 patients: 674 with renal and 127 with ureteral calculi. Results were analyzed according to stone size, location and number. The average number of shocks per treatment was 3,804 and the retreatment rate was 18.6%. At 3 months the stone-free rate was determined by a plain film of the kidneys, ureters and bladder and plain tomograms for renal calculi, and by an excretory urogram for ureteral calculi. The stone-free rate was 52% for renal and 76% for ureteral calculi. The overall stone-free rate for all calculi was 55.7%. Success rate, defined as stone-free or asymptomatic residual fragments measuring 4 mm. or less, was 72% for renal and 83% for ureteral calculi. The overall success rate for all calculi was 73.9%.

Female↗
PubMed1992

Surveillance after orchidectomy for patients with clinical stage I nonseminomatous testis tumors.

PURPOSE: This study was designed to determine the proportion of patients with clinical stage I nonseminomatous germ cell tumors of the testis (NSGCTT) managed with surveillance after orchidectomy who have more advanced disease and, therefore, require further treatment, the time to progression, the sites of progression, and the efficacy of treatment delayed until progression was recognized. PATIENTS AND METHODS: One hundred five patients were observed prospectively without further treatment after orchidectomy and full clinical staging. Treatment was given immediately upon detection of marker-positive, clinical, or radiologic evidence of disease. RESULTS: Thirty-seven patients (35.2%) have required further therapy for disease progression, occurring from 2 to 21 months after diagnosis. Thirty-six patients have been successfully treated. Overall, 104 patients (99%) remain alive and free of disease at 12 to 121 months after orchidectomy. Progression occurred in the retroperitoneum in 25 of 37 patients who developed further disease on surveillance. The presence of vascular invasion in the primary tumor was predictive of an increased risk of progression. CONCLUSION: Surveillance is a valid alternative to immediate retroperitoneal lymph node dissection in patients with clinical stage I NSGCTT but should be recommended only under the close supervision of physicians experienced in the diagnosis and treatment of testicular cancer.

Adolescent↗
PubMed1992

Vascular injury and repair associated with retroperitoneal lymphadenectomy for nonseminomatous germinal cell tumours of the testis.

Metastatic disease adjacent to major vascular structures in the retroperitoneum sometimes necessitates planned removal of portions of these vessels, or the vessels may inadvertently be injured when retroperitoneal lymphadenectomy is performed. In 78 patients who underwent retroperitoneal lymphadenectomy, 17 (22%) required vascular repair intraoperatively. The vena cava was most frequently involved (eight cases) followed by inadvertent injury to the renal arteries (five cases) or the infrarenal aorta (three cases). Resection of the infrarenal aorta was planned in two cases without postoperative complication. In six cases a resection of either the whole inferior vena cava or a portion of it was needed to remove all of the tumour. There were nine cases of inadvertent injury to the aorta, vena cava or a renal artery. The outcome after arterial repair was satisfactory with the exception of the inadvertent renal artery injuries, which required nephrectomy in three cases. Leg swelling was not a long-term sequela of either caval repair or resection.

Adolescent↗
PubMed1991

Bladder cancer: long-term follow-up results of patients treated with radical radiation.

Carcinoma of the bladder is commonly treated for cure with external beam radiation. Whilst short-term results are associated with a good chance of disease control there is little information about the long-term results of such therapy. We present a retrospective review of the Princess Margaret Hospital experience in treating transitional cell carcinoma of the bladder and emphasis on the long-term follow-up of patients treated with radiotherapy (XRT). Between 1972 and 1980, 355 patients were treated with a radical course of external beam radiation. The overall survival was 20% at 10 years and the cause-specific survival was 32%. Radiation treatment resulted in a long-term bladder preservation in at least 25% of patients. The majority of long-term survivors without evidence of relapse were patients with T1 (solitary tumours), T2 and T3a tumours. This subgroup represents patients with disease favourable for treatment with radiation. Factors affecting response to the XRT and survival included T stage and tumour bulk. Radiation complications were frequent and were usually associated with local disease recurrence.

Adult↗
PubMed1991

An assessment of combined tumour markers in patients with seminoma: placental alkaline phosphatase (PLAP), lactate dehydrogenase (LD) and beta human chorionic gonadotrophin (beta HCG).

We have assessed the tumour markers placental alkaline phosphatase (PLAP), lactate dehydrogenase (LD), and human chorionic gonadotrophin (beta HCG) using 2,000 serum samples from 286 patients with seminoma. The ROC curves show that no one marker performs adequately for the detection of disease either at initial staging or during follow-up. We used a Markov model heuristically to devise strategies, in which marker results were assessed in combination, which might be useful in clinical practice. We found that the best strategy was to consider a test result abnormal only if either the beta HCG was greater than 6 Ul-1 or the LD was greater than 400 U l-1 and the PLAP level was greater than 60 U l-1. This will detect about 50% of patients with disease and the false-positive rate is 2%. In practical terms this means that PLAP need only be estimated in patients whose beta HCG is less than 6 IU l-1 and whose LD is greater than 400 U l-1.

Alkaline Phosphatase↗
PubMed1991

Early and late complications of retroperitoneal lymphadenectomy in testis cancer.

The complications arising from 100 consecutive retroperitoneal lymphadenectomies done for nonseminomatous germ-cell tumours of the testis were reviewed. Thirty procedures were performed with sparing of sympathetic nerve fibres. There were no operative deaths. Complications were not stage-related, and the sympathetic nerve-sparing procedure did not alter their frequency. Long-term follow-up in the same cancer centre allowed documentation of all early and delayed complications as a measure of burden of surgical therapy. Median follow-up for survivors was 44 months. Complications that resulted in delayed hospital discharge or further operative intervention at any time were defined as major; all others, resulting in minimal morbidity to the patient, were documented as minor. Injury to renal vessels occurred in four patients intraoperatively. Delayed complications included small-bowel obstruction requiring laparotomy (six patients), incisional hernia requiring repair (two patients) and urethral stricture requiring urethroplasty (one patient). There were 49 complications (14 major, 35 minor) in 35 patients. The authors conclude that the majority of complications after retroperitoneal lymphadenectomy are minor and cause little morbidity. This information is useful when comparing surgery to alternative therapy with similar outcomes. The overall burden of treatment becomes all-important in the selection of optimal therapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

Effect of extracorporeal shock wave lithotripsy on bacterial viability. Relationship to the treatment of struvite stones.

The aim of this study was to determine whether extracorporeal shock wave lithotripsy (ESWL) affected the viability of the infecting bacteria within a simulated struvite stone matrix. A strain, Proteus mirabilis 28cii, was prepared in three forms: (1) suspended in saline and urine, (2) artificially encapsulated by suspending in agar beads and (3) artificially encapsulated and mineralised by suspending in agar beads with calcium carbonate crystals. The preparations were placed in capped vials partially immersed in degassed water and held in the focal point of the Siemens Lithostar and given 1,000 shocks. Subsequent viability testing showed that bacteria suspended in urine were greatly affected by shock treatments (55% loss in viability), but incorporation into agar beads negated this effect (even if the cells were exposed to 2000 shocks). Mineralisation of the beads with calcium carbonate crystals caused a decrease in viability of 82% that was significantly different from controls. However, this still left 2.3 X 10(8) viable organisms (82% of 2.8 X 10(8], easily enough to form the focus for further infections. A series of control experiments carried out using an ultrasonic cell sonicator probe gave comparable results to those obtained with ESWL. These results demonstrate the ESWL treatment of infected stones must be accompanied by antimicrobial coverage.

Humans↗
PubMed1990

Is placental alkaline phosphatase (PLAP) a useful marker for seminoma?

The usefulness of placental alkaline phosphatase (PLAP) as a tumour marker was assessed in 1578 serum samples from 236 patients with seminoma. Smoking habits were known for all but 7 patients (22 samples). Smoking was associated with significantly higher mean levels of PLAP in disease-free patients (28.8 [S.E. 2.1] U/l vs. 15.9 [1.3] U/l in non-smokers). Mean PLAP levels were higher in patients with active disease (78.6 [23.5] U/l in non-smokers and 47.2 [18.5] U/l in smokers). The median values showed a similar trend. However, there was considerable overlap between the various groups and differences between mean and median values indicated that PLAP values were distributed asymmetrically. The predictive value of PLAP as a tumour marker was consequently much less than superficial inspection of these values might suggest. In 97 patients on surveillance, only 2 out of 11 patients who relapsed had elevated PLAP at the time of clinically detectable relapse. With the upper limit of normal PLAP quoted by our laboratory (35 U/l), specificity and sensitivity were, respectively, 88% and 45% (all patients) and 96% and 47% (non-smokers). The sensitivity and specificity of PLAP were assessed in more detail for a series of threshold values (normal vs. abnormal) with a graphical method. Only in non-smokers did PLAP seem useful and even in this group the positive predictive value of an "abnormal" test may be low; less than 50% in clinically relevant circumstances. Serum PLAP assay cannot usefully stand alone as a marker for seminoma and its routine estimation contributes little to follow-up.

Adult↗
PubMed1990

Lithostar extracorporeal shock wave lithotripsy in children.

The Siemens Lithostar lithotriptor was used to treat 20 children (4 to 17 years old) with renal or ureteral calculi. Two patients had bilateral renal and 2 had ureteral calculi. Of 34 calculi treated 47% were in the renal pelvis, 29% in the lower calix, 12% in the upper calix, 3% in the middle calix and 9% in the upper ureter. Stone size ranged from 2 X 2 to 40 X 20 mm. and averaged 10 X 7 mm. Of the children 60% were treated while they were under neuroleptic anesthesia. No major complications were encountered. The 3-month rate free of stones after 1 treatment was 60% and increased to 80% with multiple treatments. The success rate, defined as being either free of stones or with residual fragments equal to or less than 4 mm. in diameter, was 95%. We conclude that lithotripsy with the Lithostar device in children, at least for the short term, is safe and effective.

Adolescent↗
PubMed1990

Inflammatory abdominal aortic aneurysms and ureteric obstruction.

Inflammatory abdominal aortic aneurysms are rare, but when they occur the ureters may be involved in the perianeurysmal fibrosis. Treatment of this ureteric involvement is controversial. The authors present one such case, review the literature and describe what they believe is the appropriate method of diagnosis and treatment. This includes the use of computed tomography, retrograde pyelography, ureteral stenting, repair of the aneurysm and ureterolysis.

Aged↗
PubMed1990

Nerve-sparing technique for retroperitoneal lymphadenectomy in testis cancer.

The technique of retroperitoneal lymphadenectomy has been modified by measures to identify and preserve the postganglionic sympathetic fibers and their ganglia and thus preserve antegrade ejaculation. Thorough bilateral lymphadenectomy can still be performed, but this technique avoids the principal morbidity of this operation except in some patients with bulky disease.

Humans↗