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Biomedical subjects

Z Amin

Publications and source records attributed to Z Amin.

50 records · Page 3Linked to original sources
PubMed1994

Interstitial laser photocoagulation as a treatment for breast cancer.

This preliminary report describes the use of interstitial laser photocoagulation to manage small breast cancers. Forty-four patients were treated with a diode laser of 805 nm under local anaesthesia in the interval between diagnosis and surgery. Ultrasonography was used in 42 patients and computed tomography (CT) in two to place the fibre in the tumour and monitor laser effects. Laser-induced necrosis within the resected tumour varied from 0 to 25 mm in diameter. The presence of charring in the tumour around the fibre tip after treatment was associated with significantly larger diameters of necrosis than when charring did not occur (median 13 versus 6 mm, P = 0.002). Precharring the fibre resulted in a more predictable diameter of necrosis (median 14 mm). Ultrasonography was inaccurate in assessing laser damage; dynamic CT and magnetic resonance imaging may be of more use. Interstitial laser photocoagulation is simple and safe, and can produce necrosis of a reasonably predictable extent.

Breast↗
PubMed1994

Recurrent upper tract urothelial tumours: the use of loopography following cystectomy for bladder cancer.

Recurrent upper tract tumours following cystectomy for transitional cell carcinoma are not uncommon. Conventional follow-up to identify preclinical recurrent disease often involves a combination of excretory urography and urine cytology. This study investigates the possible advantages of loopography in the follow-up of these patients. 41 patients who had undergone cystectomy and ileal loop diversion for transitional cell carcinoma of the bladder were studied. At the time of evaluation with a loopogram, eight out of 41 (19.5%) were symptomatic. Loopography was well tolerated by all of the patients with no reported side-effects or complications from the procedure. Six out of 41 (14.6%) of the loopograms demonstrated an abnormality with recurrent transitional cell carcinoma identified in two patients. In only one case was excretory urography necessary where a ureteric stricture prevented retrograde imaging of the upper tract. Loopography is a safe and well-tolerated investigation for the follow-up of these patients. Excretory urography should be reserved for cases where upper tract imaging is impaired because of obstruction within the loop or ureters.

Aged↗
PubMed1993

Atrioventricular canal defect: two-patch repair and tricuspidization of the mitral valve.

Between November 1978 and May 1991, a two-patch repair with tricuspidization of the left atrioventricular valve was performed in 104 patients with complete atrioventricular canal defect. Mean age was 12 months for the 68 patients who underwent primary repair and 22 months for the 36 patients who had previous pulmonary artery banding. Eleven patients died within 30 days of operation and 4 died late. Reoperation was carried out in 2 patients. Eighty-six patients were in sinus rhythm after operation. One patient required a permanent pacemaker for complete heart block. Follow-up data for 1 to 13 years are available in 80 of 89 survivors (90%). Actuarial survival at 13 years is 81% and event-free survival is 92%. Seventy-six patients are in New York Heart Association class I and 4 in class II. Postoperative echocardiogram of these patients showed minimal or no mitral regurgitation. The advantages of this technique are preservation of valve integrity, durable mitral valve repair, and rare reoperation or heart block even in younger patients.

Child, Preschool↗
PubMed1993

Colour flow and spectral Doppler imaging after papaverine-induced penile erection in 220 impotent men: study of temporal patterns and the importance of repeated sampling, velocity asymmetry and vascular anomalies.

Of 220 impotent men studied, 52 demonstrated venous leakage, 85 had arterial insufficiency and 65 showed normal vascular response. Persistent diastolic velocity > 7 cm/s diagnosed venous leakage with a sensitivity of 94% and a specificity of 69%, using cavernosography as the reference standard. Using clinical response as the reference standard maximal systolic velocity of 30 cm/s identified normal penile arterial response with a sensitivity of 96% and specificity of 82%. There was a good correlation between penile arterial insufficiency and a strong history of arteriopathy. Time to peak systole > 0.1 s was a reliable predictor of arteriogenic impotence and Pulsatility Index (PI) < 300 was discovered only in patients with either venous leakage or arteriogenic impotence. Peak systolic velocity (Tmax) occurred between 5.2 and 6.5 min after injection, and diastolic velocity was minimal at 9 min with only the normal responders showing reversed diastolic flow. However, 22% had a delayed response (Tmax range 1-18 min). Velocity asymmetry was equally common in the three groups and unilateral sampling would have misdiagnosed 6% of patients studied. Vascular anomalies were seen in 13%, particularly a single feeding artery, dorsal vein flow or collateral arterial flow.

Adult↗
PubMed1993

Local treatment of colorectal liver metastases: a comparison of interstitial laser photocoagulation (ILP) and percutaneous alcohol injection (PAI).

The purpose of this study was to evaluate the relative merits of two physical methods of locally destroying colorectal liver metastases-interstitial laser photocoagulation (ILP) which causes thermal necrosis, and percutaneous alcohol injection (PAI) which causes cellular dehydration and coagulative necrosis. Seventy-six liver metastases in 22 patients were treated by ILP or PAI. Both techniques were performed using local anaesthesia and intravenous sedation/analgesia. Ultrasound was used to localize the tumours and guide the needles percutaneously. ILP: Up to eight 19 G needles were inserted into the tumour, and down each needle was passed a thin optical fibre; the tumour was heated using low power laser light (2 W) for 500 s from a Nd:YAG or diode laser. PAI: 0.5-1 ml of sterile 95% absolute alcohol was injected into multiple sites of the tumour using a single 19-22 G needle. Dynamic CT scan was used to evaluate the extent of treatment-induced necrosis. Ultrasound showed echogenic changes around the needles/fibre-tips during ILP and PAI; this gave a reasonable guide to the extent of thermal damage for smaller tumours during ILP, but not during PAI. ILP: 54 tumours were treated (median size 2.7 cm). Laser-induced necrosis was clearly seen 24 h after treatment as a well-defined area of non-enhancement on the dynamic CT scan; greater than 50% necrosis of tumour volume was achieved in 87% of tumours (complete necrosis was found in 52% of tumours). PAI: 22 tumours were treated (median size 1.5 cm). Dynamic CT showed patchy areas of non-enhancement in five tumours, decreased density in seven tumours, and no change in 10 tumours; complete tumour necrosis was never achieved. There were no major complications after ILP or PAI, but pain during treatment was more common and more severe with PAI. ILP is a simple, safe and effective treatment for colorectal liver metastases; PAI is relatively ineffective for these tumours (although it has been shown to be much more effective for small hepatocellular carcinomas).

Adult↗
PubMed1993

Computed tomography-pathologic assessment of laser-induced necrosis in rat liver.

RATIONALE AND OBJECTIVES: Interstitial laser photocoagulation (ILP) causes localized tissue necrosis. This study was performed to determine 1) whether the changes seen on computed tomography (CT) correspond to the necrosis pathologically, and 2) which CT technique best shows the necrosis. METHODS: Eighteen Wistar rats had ILP to their liver using a neodymium yttrium aluminum garnet [Nd:YAG] laser. Radio-opaque markers attached to the liver defined an imaging plane. Precontrast "dynamic" and delayed CT scans were performed. The size of necrosis was measured on CT, and macroscopically after resecting the liver. Computed tomography density numbers were measured from the necrotic area and normal liver for each CT technique. RESULTS: There was a good correlation between the necrosis size on CT and pathologically (P < .001). Maximum lesion-to-liver contrast was obtained on "dynamic" CT scans. CONCLUSIONS: The extent of tissue density changes on CT in rat liver after ILP match the extent of necrosis seen pathologically. The best CT technique use assessed for evaluating laser-induced liver necrosis is dynamic contrast-enhanced scanning.

Animals↗
PubMed1993

Hepatic metastases: interstitial laser photocoagulation with real-time US monitoring and dynamic CT evaluation of treatment.

Fifty-five liver metastases in 21 patients were treated with interstitial laser photocoagulation (ILP). Tumors were irradiated with a neodymium yttrium aluminum garnet laser via optical fibers passed through 19-gauge needles inserted under ultrasound (US) guidance. Heating of the tumor was evident at real-time US as an expanding and coalescing echogenic zone around the needle tips. After ILP, dynamic computed tomography (CT) showed laser-induced necrosis as a new area of nonenhancement. Necrosis of tumor volume was more than 50% in 82% (45 of 55) of the tumors, and 100% necrosis was achieved in 38% (21 of 55). Metastases smaller than 4 cm in diameter were treated more effectively and required fewer treatment sessions than did those larger than 4 cm. Complications were minor and included severe pain in four cases, persistent pain for up to 10 days in 11 cases, and asymptomatic subcapsular hematoma (four cases) and pleural effusion (six cases) seen with CT. ILP is safe and effective for liver tumor destruction, and US and CT are useful in different aspects of treatment monitoring.

Adult↗
PubMed1993

Colour Doppler and duplex ultrasound assessment of Peyronie's disease in impotent men.

280 patients (aged 28 to 74 years, mean 57) with erectile failure (EF) underwent colour Doppler and duplex ultrasound imaging (CDI) following intracorporeal papaverine. After achieving a full, or nearly full, erection visual inspection and palpation revealed plaques and/or constriction or deformity of the penis in 55 (20%) cases. 10 (4%) were known to have Peyronie's plaques prior to referral. Of these 55 patients ultrasound showed focal echogenic plaques in 14 (25%) and diffuse thickening of the tunica albuginea in 41 (75%). CDI diagnosed arteriogenic EF in 20 (36%) of these patients, venous leak in 10 (18%), arterial and venous in two (4%) and a normal response in 23 (42%). In 11 (20%) patients (seven with arteriogenic EF and four with venous leak) the plaque was seen to be affecting vessels. These results indicate that abnormalities of the tunica albuginea are far more common in patients presenting with erectile failure than previously thought. We believe that the diffuse thickening is a form of Peyronie's which is only recognized after pharmacological induction of penile erection.

Adult↗
PubMed1993

Technical note: interstitial laser photocoagulation for the treatment of prostatic cancer.

Interstitial laser photocoagulation (ILP) is a new percutaneous technique for local ablation of deep-seated tumours. We have applied this to treat a focal abnormality in a patient with prostatic carcinoma, under local anaesthesia and sedation. Transrectal ultrasound and computed tomography (CT) were used to guide three 18G needles, inserted transperineally, into the abnormal area. A thin (0.8 mm outer diameter) optical fibre was passed down each needle, so that the tip of the fibre lay within the tumour. The other end of the fibre was connected to a portable diode laser, which was activated at 2 W for 500 s. Real-time monitoring with ultrasound showed a gradually enlarging echogenic zone around the fibre-tip and a marked increase in colour Doppler signal; the echogenicity and Doppler signal decreased within a few minutes of completing treatment. Dynamic CT treatment 10 days later showed the treated area as a non-enhancing, avascular zone. Biopsies from this region confirmed the presence of necrosis. There were no complications. ILP appears to be a safe and effective way of ablating areas of focal abnormality in the prostate.

Aged↗
PubMed1993

Interstitial tumour photocoagulation.

Interstitial laser photocoagulation (ILP) is a new technique of in situ tumour destruction, using low power laser light energy, delivered percutaneously via thin optical fibres. We have applied this to treat patients with tumours of the liver, breast, and prostate, using sedation and local anaesthesia, and an Nd:YAG (1064 nm) laser or a new portable diode (805 nm) laser. Tumour necrosis has been optimized by using a 1 x 4 fibre coupler which splits the laser beam, and allows equal delivery of energy down 4 fibres simultaneously; the most promising results to date are with treating liver metastases with smaller tumours (< 3 cm) often being completely destroyed. With further improvements in laser parameters and fibre-tips, and in the evaluation of the thermal effects of ILP by imaging, it may be possible to apply this technique to completely destroy small deep-seated tumours in other organs. With optimal technique, ILP may in the future become a practical, minimally invasive treatment option for patients with tumours of the liver and breast, in conjunction with systemic therapy.

Adenocarcinoma↗
PubMedDate not supplied

A novel use of Amplatzer duct occluder.

This report describes the use of the Amplatzer patent ductus arteriosus occluder to close a left ventricle to descending aorta conduit. The patient was a 10-year-old male who was born with critical aortic stenosis and left ventricular outflow tract obstruction. After initial valvotomy, he underwent left ventricular to descending aorta conduit placement. At the age of 10, he had a Konno procedure to enlarge the left ventricular outflow tract and 21-mm St. Jude aortic valve placement. Closure of the conduit was not addressed because it was inaccessable from median sternotomy. Postoperatively, echocardiogram revealed significant flow through the conduit with a wide pulse pressure. Cardiac catheterization was performed with the premise to close the conduit with an Amplatzer patent ductus arteriosus occluder device.

Aortic Valve Stenosis↗
PubMedDate not supplied

Mycobacterium tuberculosis Beijing genotype strains associated with febrile response to treatment.

DNA fingerprinting has demonstrated predominance of the Beijing genotype among Mycobacterium tuberculosis strains isolated in Southeast Asia. We prospectively examined the occurrence of Beijing genotype strains in tuberculosis patients in Indonesia. Early in treatment, patients infected with Beijing genotype strains more often had fever unrelated to disease severity, toxicity, or drug resistance, indicating that Beijing genotype strains may have specific pathogenic properties.

Adolescent↗