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Biomedical subjects

A Chavan

Publications and source records attributed to A Chavan.

At least 37 records · Page 2Linked to original sources
PubMed1998

Arterial chemoembolization before liver transplantation in patients with hepatocellular carcinoma: marked tumor necrosis, but no survival benefit?

BACKGROUND/AIMS: Hepatic artery chemoembolization was introduced in the treatment of patients with unresectable hepatocellular carcinoma waiting for liver transplantation. The rationale for this preoperative treatment was to control tumor growth during the waiting period and to improve long-term survival. This study aimed to investigate whether preoperative chemoembolization not only induces marked tumor necrosis but also has a survival benefit. METHODS: In this study 21 patients with hepatocellular carcinoma who underwent pretransplant chemoembolization (group I) were compared with 21 historical control patients (group II) without preoperative chemoembolization in a case-control study. The number of pretransplant chemoembolizations in each patient in group I varied between 1 and 5 with a mean of 2.44+/-1.15. In addition, six patients of this group received preoperative systemic chemotherapy. RESULTS: Overall, there were no differences in survival between the groups with and without pretransplant chemoembolization at 1 year (60.8% vs 61.5%) and at 3 years (48.4% vs 53.9%). In group I, three patients developed unexplained severe pneumonia, leading to death very early after liver transplantation. Marked tumor necrosis (>50%) was found in 14 cases in group I. In 6 out of these 14 patients, total tumor necrosis was observed. CONCLUSION: Although preoperative chemoembolization or chemotherapy induced marked tumor necrosis, these patients showed no benefit in survival compared to historical controls, and appeared to be at higher risk of developing immediate postoperative infective complications.

Carcinoma, Hepatocellular↗
PubMed1998

[3D and color Doppler ultrasound evaluation of cystic space-occupying lesion near the head of the pancreas].

AIM: Differential diagnosis of cystic lesions in the abdomen may be very difficult. We present the clinical manifestation and the diagnostic steps of a rare case of an aneurysm of the gastroduodenal artery mimicking a cystic lesion. We also discuss the imaging methods we used to verify the diagnosis such as colour Doppler sonography and 3D-sonography. METHOD AND PATIENT: A 42-year old woman with chronic pancreatitis was admitted to our hospital after an extended diagnostic program (sonography, computed tomography and laparoscopy) with the diagnosis of a pancreatic pseudocyst with vascular erosion. Using conventional sonography we found a cystic lesion of 5 x 5 cm diameter with parietal deposits between pancreas and coeliac trunk. After colour Doppler sonography we found an arterial jet in the cystic tumor; initially the source of the jet seemed to be the hepatic artery. We referred the patient to our department of radiology with the diagnosis of hepatic artery aneurysm. The aneurysm was confirmed by the angiography and was embolised with coils in the same session. However, the source of the aneurysm was not the hepatic, but the gastroduodenal artery. By postangiographical 3D-sonography we could clearly reconstruct the relation of the aneurysm to the gastroduodenal artery. CONCLUSION: Colour Doppler sonography should be the first imaging tool for clarifying cystic lesions in the abdomen. 3D-sonography is a reliable and useful method to identify visceral vessels of the abdomen. Nowadays the "gold standard" angiography should preferably be used as a therapeutic procedure.

Adult↗
PubMed1998

Transarterial chemoembolization and percutaneous ethanol injection therapy in patients with hepatocellular carcinoma.

Both transcatheter arterial chemoembolization (TACE) and percutaneous ethanol injection therapy (PEI) have proven their efficacy in patients with unresectable hepatocellular carcinoma (HCC): TACE mainly in large lesions or disseminated disease and PEI in solitary lesions smaller than 3 cm. Although severe complications have been observed with both methods, their incidence is low. In 1991, the combination therapy of initial TACE followed by multiple sessions of PEI was introduced, allowing the repeated percutaneous treatment of lesions larger than 4 cm. This approach has been shown to be more effective than TACE alone in lesions up to 8 cm in diameter. An increased incidence of serious side-effects compared to either method alone has not been reported so far.

Carcinoma, Hepatocellular↗
PubMed1998

Clinical outcome of transfemoral embolisation in patients with arteriovenous malformations of the liver in hereditary haemorrhagic telangiectasia (Weber-Rendu-Osler disease).

BACKGROUND: Arteriovenous malformations of the liver in Osler's disease may present as high output cardiac failure. A few case reports suggested that treatment with arterial embolisation may have beneficial effects in such patients. AIMS: To investigate the efficacy and safety of this treatment modality in a prospective pilot study. PATIENTS AND METHODS: Four women and one man (aged 39-59 years) with the dominant hepatic manifestation of Osler's disease presented with symptoms of cardiac failure and elevated cardiac output. Arteriovenous malformations were treated in three to five sessions with arterial embolisation using coils. The outcome was analysed by measurement of cardiac output and scoring of clinical symptoms. RESULTS: Embolisation was technically feasible in all patients and adequate occlusion of vascular malformations was achieved in four patients. After completion of therapy symptoms improved in four patients, while one patient suffered from abdominal pain due to cholangitis. One patient died seven months after the embolisation treatment from variceal bleeding. Mean cardiac output significantly decreased from 14.2 (range 12-17.3) l/min to 8 (range 5.9-10.6) l/min (p = 0.043). After a median follow up of 23 months (range 7-50 months), three of five patients had a long lasting improvement of clinical symptoms and cardiac function. CONCLUSIONS: This first treatment series of patients with dominant hepatic involvement in Osler's disease indicates that arterial embolisation may prevent cardiac failure by significantly lowering cardiac output.

Adult↗
PubMed1998

Hereditary hemorrhagic telangiectasia: effective protocol for embolization of hepatic vascular malformations--experience in five patients.

PURPOSE: To develop a hepatic artery embolization protocol and investigate its efficacy in a prospective study treating patients with hereditary hemorrhagic telangiectasia and predominant hepatic involvement. MATERIALS AND METHODS: One man and four women with hereditary hemorrhagic telangiectasia presented with symptoms of high-output heart failure, abdominal angina, or severe portal hypertension. The hepatic arteries were embolized in stages in three to five sessions at 1- to 15-week intervals. After peripheral embolization with polyvinyl alcohol particles, proximal arteries were embolized with coils. Computed tomography and assessment of cardiac output were performed before and after therapy and at the end of follow-up (median, 25 months; range, 12-55 months). RESULTS: After embolization, analgesics and antiemetics were necessary for a median of 5 and 2 days, respectively. Other than ischemic cholangitis (one patient), no complications were observed. The mean cardiac output decreased significantly (P < .05) from 14.2 L/min to 8.0 L/min. Symptoms of high-output heart failure, abdominal angina, and portal hypertension resolved in all patients. Seven months after embolization, one patient died of postoperative sepsis after an unsuccessful surgical attempt to create a portacaval shunt. Delayed recurrence of symptoms was not noted in the other patients. CONCLUSION: In symptomatic patients with hereditary hemorrhagic telangiectasia and predominant hepatic involvement, embolization of the hepatic arteries in stages is well tolerated by the patients and results in good clinical improvement at midterm follow-up.

Adult↗
PubMed1998

First experience and technical aspects of isolated liver perfusion for extensive liver metastasis.

BACKGROUND: New drugs and modalities for locoregional tumor treatment in recent years may offer new potential for isolated liver perfusion in patients with nonresectable liver tumors. The purpose of this study was to prove the feasibility of arterial isolated liver perfusion and to assess the tolerance of perfusion with high-dose tumor necrosis factor (TNF). METHODS: Twelve patients with extensive liver metastases previously treated unsuccessfully with systemic chemotherapy underwent isolated hyperthermic liver perfusion using a heart-lung machine. High doses of mitomycin were administered in the first six and a combination of TNF and melphalan in the last six patients. RESULTS: No operative death occurred and no direct postoperative liver failure was observed in any patient. In cases of variations of the arterial hepatic blood supply, the perfusion was done through the splenic artery or an angiography catheter. Histologic analysis of tumor biopsy specimens obtained on the first postoperative day revealed major tumor necrosis in 8 of 12 patients. CONCLUSIONS: Isolated arterial perfusion of the liver is a complex surgical procedure that is feasible in patients with anatomic variations of the hepatic artery. The remarkable histologic response to perfusion in several pretreated patients, especially after application of high-dose TNF and melphalan, suggests that this modality is very effective in tumor killing.

Adult↗
PubMed1997

Intravascular ultrasound-guided percutaneous fenestration of the intimal flap in the dissected aorta.

BACKGROUND: Aortic dissection with branch obstruction is associated with high morbidity and mortality. Fenestration of the dissection flap to relieve distal vessel ischemia is at present largely performed surgically. The surgical mortality and morbidity are high, because most patients are poor candidates for anesthesia or surgery. METHODS AND RESULTS: Nine percutaneous fenestrations (one with additional stenting of the infrarenal true aortic lumen) were performed under local anesthesia in seven patients with aortic dissection. The presenting symptoms were abdominal angina or claudication. By the transfemoral approach, the intimal flap was initially punctured with a needle-catheter combination through which a guidewire was placed across the dissection flap. The fenestration was carried out with a balloon catheter introduced over the guidewire. The procedure was performed under on-line guidance with intravascular ultrasound imaging. The procedure was performed successfully and without complications in all patients. After intervention, symptoms resolved in all seven patients. CONCLUSIONS: Intravascular ultrasound-guided percutaneous fenestration of the intimal flap in symptomatic aortic dissections with distal vessel involvement is a technically feasible and safe procedure that can effectively relieve the patient's symptoms.

Adult↗
PubMed1997

Site-specific photobiotinylation of immunoglobulins, fragments and light chain dimers.

Herein we report a new method to rapidly photoinsert biotin into a specific and highly conserved site on the Ig structure using a mild photochemical activation step. This site resides in the Fv fragment and involves invariant residues which provide base stacking interactions to the purine ring of ATP (Rajagopalan et al. (1996) Proc. Natl. Acad. Sci. USA 93, 6019-6024). Biotin was coupled to either the phosphate or the ribose of the 8-azidopurine nucleotide or nucleoside photoaffinity probe and shown to insert into the affinity site efficiently. Several monoclonal and polyclonal antibodies, as well as enzymatic and recombinant antibody fragments and light chain dimers were photoaffinity biotinylated and used in ELISA, FACS and Western blots. The selectivity of this site-specific biotinylation method also allows for biotinylation of antibodies in culture supernatants and immune sera without prior purification. Because the biotinylation takes place under physiological conditions and within a short time period, photobiotinylation would be the preferred method for antibodies which are easily damaged by classical non-site specific random biotinylation chemistry.

Animals↗
PubMed1996

Recurrent angina pectoris in patients with internal mammary artery to coronary artery bypass: treatment with coil embolization of unligated side branches.

PURPOSE: The purpose of the study was to evaluate the effect on the symptoms of transcatheter coil embolization of branches of the internal mammary artery. MATERIALS AND METHODS: In five patients with coronary steal syndrome that was caused by preferential flow in large unligated side branches of the internal mammary artery, coil embolization of the side branches was performed with use of a coaxial microcatheter. RESULTS: Anginal symptoms disappeared in three patients and were substantially reduced in one patient following the radiologic intervention. In the fifth patient, who had concomitant stenoses of other coronary vessels, only a moderate change in symptoms was noted. No complications occurred. CONCLUSION: In patients with internal mammary artery to coronary artery bypass who experience recurrent angina pectoris caused by preferential flow in large, unligated side branches of the internal mammary artery, repeat surgery may be circumvented or simplified by transcatheter coil embolization, which can help treat the angina.

Adult↗
PubMed1996

Percutaneous superselective coil-embolization of intrarenal arteriovenous fistulas. Case reports.

PURPOSE: To evaluate the role of percutaneous transcatheter coil-occlusion in the management of uncontrollable postoperative hematuria due to iatrogenic arteriovenous (AV) fistulas. MATERIAL AND METHODS: In 2 patients, AV fistulas were occluded with percutaneous catheter-guided superselective coil embolization. RESULTS: In both cases, occlusion of the AV fistulas was successful. Only small parts (less than 10%) of the parenchyma had to be sacrificed. No hypertension occurred. CONCLUSION: Percutaneous coil embolization is a useful alternative to surgery in cases of postoperative AV fistulas. Hematuria can be effectively controlled without resulting hypertension.

Adult↗
PubMed1996

[Hereditary hemorrhagic telangiectasia with hepatic involvement and including gastric vessels. A case report].

Hereditary hemorrhagic teleangiectasia (HHT) (Osler-Weber-Rendu-disease) is characterized by a combination of muccocutaneous vascular malformations with recurrent spontaneous bleeding and a familiar predisposition. Among visceral manifestations of this disease are only a few descriptions of hepatic involvement. We describe a 53-year-old woman with HHT whose first symptoms of hypercirculatory heart failure developed 1.5 years before the final diagnosis of HHT. We measured a heart-time-volume of 14-151/min. by echocardiography and a flow-volume of 5-9 l/min. in the proper hepatic artery by dopplersonography on admission. We were able to demonstrate multiple intra- and extra-hepatic and gastric arteriovenous malformations by arteriography. Branches of the proper hepatic artery and the left gastric artery were embolized in three serial sessions. By this procedure we were able to reduce the flow-volume in the proper hepatic artery from 5-9l/min. to 1.5l/min. and the heart-time-volume to a minimum of 9.8l/min. and thus stop progression of the hyperdynamic heart failure.

Angiography↗
PubMed1995

Inhibition of granulocyte-macrophage colony-stimulating factor (GM-CSF) activity by suramin and suramin analogues is correlated to interaction with the GM-CSF nucleotide-binding site.

Suramin and suramin analogues strongly inhibit both nucleotide interaction with the nucleotide-binding site of granulocyte-macrophage colony-stimulating factor (GM-CSF) and bioactivity of the molecule as assessed by competition photoaffinity labeling and cell proliferation assay, respectively. The half-maximal inhibition of cell proliferation by suramin occurs at 68 +/- 2.5 microM; three suramin analogues achieved comparable activity. The degree of competitive inhibition of nucleotide-binding by these compounds and the inhibition of GM-CSF bioactivity are correlated such that the compounds show similar rank-order by both of these methods. The strong interaction of suramin and related compounds with the nucleotide-binding site may mimic nucleotide-mediated inhibition of GM-CSF bioactivity and may be an important mechanism by which suramin acts as a pharmacological anti-growth factor agent.

Binding Sites↗
PubMed1995

Minimally invasive diagnosis of renal artery stenosis by spiral computed tomography angiography.

We prospectively compared in a blinded fashion spiral computed tomography angiography (CTA) with arteriography in 62 consecutive patients with suspected renal artery stenosis (RAS). For CTA 150 ml of contrast material were injected intravenously. Arteriography was performed by DSA technique with selective catheterization of renal arteries. Of the 157 visualized renal arteries 155 could be evaluated with DSA and a total of 157 with CTA. Sensitivity of CTA for RAS > or = 50% was 98% and the specificity was 94%. Comparison of the grade of stenosis as evaluated by DSA versus CTA showed: identical gradation in 59 arteries (DSA > or = 50%/CTA > or = 50%), underestimation by CTA in one artery (DSA 50 to 75%/CTA < 50%), and overestimation by CTA in six arteries (DSA < 50%/CTA 50 to 75%). Factors that may contribute to these differences include impaired renal function and possibly "underestimation" of ostial RAS by arteriography. One artery not evaluable by arteriography showed a 70% stenosis by CTA. CTA showed no major side effects. We conclude that CTA has the same accuracy for the diagnosis of RAS > or = 50% as arteriography. However, CTA is only minimally invasive, safe, and causes less discomfort to patients.

Adult↗
PubMed1995

Recurrence of hepatitis B virus cirrhosis and hepatocellular carcinoma: an indication for retransplantation?

Hepatitis B virus reinfection as well as recurrence of hepatocellular carcinoma are frequent complications in liver allograft recipients. This is the report of a patient who had two liver transplantations with a 6-year interval, both for the same indication-postnecrotic cirrhosis and liver cancer. Following first and second transplantation, hepatitis B reinfection occurred at 12 and 6 months, and allograft cirrhosis developed after 20 and 10 months, respectively. Intrahepatic recurrence of hepatocellular carcinoma was found after 69 months. Two years following retransplantation, the patient is tumor-free, and has normal graft function. In selected patients with hepatitis B-related liver disease, and hepatocellular carcinoma liver replacement is indicated when combined with effective immunoprophylaxis, and other adjuvant therapy. Late recurrence of both diseases is unusual, and retransplantation may come into question.

Carcinoma, Hepatocellular↗
PubMed1994

[Accuracy of CT angiography in the diagnosis of renal artery stenosis].

Spiral CT in the form of CT angiography (CTA) provides a new method for the investigation of the large vessels. 52 patients with suspected renovascular hypertension were examined by CTA and arterial DSA. The computer tomographic and angiographic findings in 124 renal arteries were compared. Sensitivity of CTA for demonstrating renal artery stenosis was 95%, and for relevant stenoses it actually reached 100%. Specificity was 92%. Positive/negative prediction value was 85% and 100%. CTA proved outstandingly good for demonstrating or excluding renal artery stenosis and was superior to other imaging methods in several respects. CTA requires high contrast values, optimal timing and careful evaluation. Amongst various forms of image reconstruction, interactive viewing of the primary axial images and multiplanar reconstruction in a cine mode are essential and MIP projections are valuable.

Adult↗
PubMed1994

Vascular complications in adult patients after orthotopic liver transplantation: role of color duplex sonography in the diagnosis and management of vascular complications.

Vascular complications after orthotopic liver transplantation are one of the most serious problems in liver-grafted patients, and if undetected they may result in graft failure and death unless prompt revascularization or retransplantation is performed. As the outcome of treatment of vascular complications depends on an early diagnosis, the role of color-coded duplex sonography (CCD) for diagnosis and treatment was analyzed during a 17-month observation period. Altogether, 88 consecutive liver allografts in 77 adult patients were studied by serial CCD. Vascular complications occurred with an incidence of 12.9%. Hepatic artery complications represented the most frequent event with an incidence of 11.6%. CCD showed a sensitivity of 100%, a specificity of 97% and a positive predictive value of 0.84. With the use of CCD, vasculature and localization of the site of arterial complications can be directly visualized and the various types of complications can be differentiated, thus reducing the time needed for diagnosis. Early hepatic artery complications, occurring during the first 3 days after transplantation, which were immediately diagnosed by CCD examination and rapidly treated by revascularization had a good clinical outcome. In contrast, the outcome of vascular complications requiring retransplantation was found to be poor. As radiologic intervention offers an alternative to the treatment strategy of vascular complications in liver-grafted patients, CCD is the method of choice to noninvasively monitor the initial and follow-up examinations after intervention.

Adolescent↗