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B Rawat

Publications and source records attributed to B Rawat.

At least 19 recordsLinked to original sources
PubMed2005

Colo-colonic intussusception caused by a solitary Peutz-Jeghers polyp.

A case of acute large bowel obstruction by colo-colonic intussusception in a healthy 19-year-old man is presented. The lead point of the intussusception is a rare solitary colonic Peutz-Jeghers polyp in the descending colon of a man without the full Peutz-Jeghers syndrome. The clinical presentation, imaging findings on plain radiographs, single contrast enema and CT, and findings at colonoscopy and surgery are correlated with pathology results and a brief review of the literature.

Adult↗
PubMed1996

Value of three-dimensional gradient-echo magnetic resonance cholangiography in diagnosing choledocholithiasis.

OBJECTIVE: To evaluate the role of magnetic resonance cholangiography (MRC) in patients with suspected choledocholithiasis. PATIENTS AND METHODS: Twenty-six consecutive patients with suspected choledocholithiasis (11 men and 15 women ranging in age from 25 to 81 years) underwent three-dimensional gradient-echo MRC; each patient also underwent endoscopic retrograde cholangiography or operative cholangiography. Each set of images for each patient was reviewed independently by a radiologist who was unaware of the results of the other type of imaging. RESULTS: Diagnostic-quality MRC images were obtained for 17 of the patients. Of these, 13 had stones in the common bile duct, as confirmed by another imaging method, and MRC indicated the presence of these stones in all 13 patients. In the other four patients bile duct obstruction was due to either acute pancreatitis (in three) or cholangiocarcinoma (in one). For seven of the nine nondiagnostic-quality MRC studies, the bile duct was not obstructed, so there was no bile stasis and the MRC images could not be obtained. Motion artifacts due to inability to hold the breath were the limiting factors in the other two patients. CONCLUSION: Although MRC has some limitations, this new noninvasive technique may be used as a screening test in selected patients with suspected choledocholithiasis.

Acute Disease↗
PubMed1995

Morphine selectively depresses the slowest, NMDA-independent component of C-fibre-evoked synaptic activity in the rat spinal cord in vitro.

The effects of morphine on the depolarizing synaptic responses produced in motoneurons by electrical stimulation of primary sensory neurones have been recorded in hemisected spinal cord preparations (8- to 12-day-old rat pups). Morphine at concentrations of 0.1-20 microM reduced a slow, long-lasting (latency greater than 1 s, duration up to 10 s) component of the ventral root potential (VRP) evoked by C-fibre strength stimulation of the dorsal root. At 2 microM the reduction in area of this slow synaptic potential was 71.7 +/- 0.9% of control values (n = 15). The earliest components of the C-fibre strength VRP (the first 100 ms) and the responses to A beta strength stimuli were unaffected by the opioid even at 10-20 microM. The intermediate, NMDA receptor antagonist (D-AP5, 40 microM)-sensitive component (which lasts 100-1000 ms) was reduced by 34 +/- 2.2% of control (n = 15), which was significantly less than the reduction of the later NMDA-independent component (P < 0.001). Morphine (0.1-20 microM) also depressed the cumulative depolarization generated by the temporal summation of synaptic responses evoked by brief trains of C-fibre strength stimuli (1 or 10 Hz). A significantly greater reduction at the lower frequency of stimulation (56.3 +/- 2.0%) than at the higher (20.3 +/- 1.69%, n = 10, measured at 2 microM morphine) was found (P < 0.005). The effects of morphine were reversible upon wash-out or superfusion with the opioid receptor antagonist naloxone (2 microM).(ABSTRACT TRUNCATED AT 250 WORDS)

2-Amino-5-phosphonovalerate↗
PubMed1995

Extracranial metastases of meningioma.

We report two unusual cases of intracranial meningioma with extracranial metastases to bone. The diagnosis was made by fine needle aspiration biopsy in both cases and confirmed by open biopsy in one. The lungs were spared in both. A review of the literature is included.

Adult↗
PubMed1994

Case report: rapidly progressive neuropathic arthropathy in syringohydromyelia--radiographic and magnetic resonance imaging findings.

A rapidly progressive neuropathic shoulder joint in a patient with syringohydromyelia is presented. He developed marked destruction of the shoulder joint over 5 weeks. The MRI findings in the pre- and post-resorptive phases of the arthropathy are presented for the first time. Low signal intensity areas are observed in the medullary cavity of the bone on both T1- and T2-weighted spin-echo images even before the actual resorptive process starts. Additional major findings are the joint effusion and synovial thickening.

Adult↗
PubMed1992

Extracorporeal shockwave lithotripsy of pancreatic duct stones.

Encouraging results with extracorporeal shockwave lithotripsy (ESWL) for pancreatic duct stones have been reported from Europe. We present our experience with the first two North American patients, treated with excellent results in one and limited clinical improvement in the other patient at 1 year follow-up. Targeting of pancreatic duct stones was achieved with either fluoroscopy or ultrasound.

Adolescent↗
PubMed1992

Optimizing gallbladder stone lithotripsy: an international survey.

Rates of stone clearance with extracorporeal shock wave cholecystolithotripsy (biliary lithotripsy [BL]) initially reported by European groups were encouraging. An American multicenter BL study (the Dornier National Biliary Lithotripsy Study [DNBLS]) did not reproduce these results. The BL treatment strategies and 6-month stone clearance rates of six leading European and Japanese centers were compared with those of DNBLS. All foreign centers used adjuvant oral chemolitholysis and greater shock wave energies from the same lithotriptor as that in DNBLS. Six months after BL, the stone clearance rates at all six centers were higher than those of DNBLS. There were no significant differences in complication rates between centers. These findings suggest that the poor results of DNBLS were chiefly due to the use of low kilovoltage and few BL sessions. Increased energy levels and a fragment size end point of less than 5 mm optimize BL. Despite the popularity of laparoscopic cholecystectomy, BL can be recognized as a successful treatment alternative for patients with a low burden of radiolucent stones.

Cholelithiasis↗
PubMed1991

Effectiveness of transcutaneous electrical nerve stimulation (TENS) for analgesia during biliary lithotripsy.

The effectiveness of transcutaneous electrical nerve stimulation (TENS) in controlling pain during biliary extracorporeal shockwave lithotripsy (BESWL) was assessed in 100 patients with symptomatic gallbladder calculi. Patients were divided into four groups: TENS electrodes were placed on the back at cutaneous anesthesia sites and on the right leg and the gallbladder acupuncture site in groups A and B. Electrodes were "turned on" only in group A. In groups C and D, electrodes were placed only on the back at cutaneous dermatomes. Electrodes were "turned on" in group C only. The TENS unit was stimulated at the pulse rate of 60 to 100 microseconds and frequency of 80 to 125 Hz. Lithotripsy was performed with the Lithostar Plus overhead module. The differences in the amount of analgesic used and the pain experiences by the patients in all groups were not statistically significant. The proportion of patients requiring intravenous analgesia in each group was also not significantly different (72%, 80%, 68%, 76% in groups A to D, respectively). Thus, TENS did not help in reducing the amount of intravenous analgesia required or the average pain perceived by the patient during lithotripsy treatment.

Analgesia↗
PubMed1991

Long-term soft-tissue effects of biliary extracorporeal shock waves: an animal study.

Although delayed effects of renal extracorporeal shock-wave lithotripsy (ESWL) have been reported, the long-term soft-tissue effects after biliary ESWL have not been investigated. We report soft-tissue effects seen up to 1 year after biliary extracorporeal shock waves were administered to 18 Yucatan pigs. The gallbladder received 4000 electromagnetic shock waves from a Siemens Lithostar overhead module. Blood samples were drawn from each pig for hematologic, coagulation, and biochemical profiles immediately before and then at prescribed time intervals after administration of shock waves. Autopsy and histopathologic examination of the gallbladder and surrounding organs were performed. Kidneys and adrenal glands also were examined in five pigs followed up for 1 year. There were no gross or microscopic abnormalities in 11 animals, including all five animals in the 1-year group in which kidneys and adrenal glands also were normal. One animal (3-week group) had two 2-mm foci of parenchymal necrosis in the right lobe of the liver, probably related to ischemia after shock-wave therapy. Transient rise in liver and pancreatic enzyme levels was seen in most animals after administration of shock waves. The levels returned to normal within 2 months in all but one animal. We conclude that biliary ESWL with the Lithostar Plus does not produce long-term histologic evidence of organ damage in Yucatan pigs.

Adrenal Glands↗
PubMed1991

Altered gallbladder contractility after extracorporeal shock-wave cholecystolithotripsy.

Change in gallbladder contractility after biliary extracorporeal shock-wave lithotripsy (ESWL) may significantly influence the clearance of fragments after successful gallstone fragmentation. We assessed changes in gallbladder contractility in response to an oral fatty meal in 50 patients 1 month after biliary ESWL (all fragments were smaller than 3 mm) and also in a separate group of 10 patients 3 months after complete clearance of fragments. The prevalence of persistent lumen-obliterating contraction of the gallbladder after biliary ESWL also was analyzed in 325 patients. Gallbladder contractility remained unchanged in 30, increased in nine, and decreased in 11 of the 50 patients. The average reduction in the fasting gallbladder volume after lithotripsy was 28% (p less than .001). Gallbladder contractility remained unchanged 3 months after complete clearance of fragments in six of 10 patients studied separately. A decrease (n = 2) or increase (n = 2) in contractility was seen in the remaining patients. No significant difference occurred in the average ejection fraction of the gallbladder before lithotripsy and after complete clearance of the fragments. Thirty-four of the 325 patients who have so far undergone biliary ESWL had a completely contracted gallbladder with no lumen visible on sonography. The gallbladder returned to a relaxed state in half of these patients within 1-9 months. Thus, biliary ESWL did not significantly alter gallbladder contractility in 60% of patients. A significant reduction in the volume of the fasting gallbladder occurred after lithotripsy. Successful clearance of fragments did not improve the contractility of stonebearing gallbladders in the majority of patients.

Cholecystokinin↗
PubMed1990

The intercostal pathway for biliary lithotripsy: an evaluation.

Intercostal biliary extracorporeal shock wave lithotripsy (BESWL), an alternative method for targeting retrocostal gallbladders, was evaluated in a three-stage study. First, 10 pigs (three with implanted gallstones) underwent BESWL at different, increasing shock wave pressures. Histologic studies were done in seven animals and showed no macroscopic abnormalities. Microscopically, two pigs had 1-3-mm blood collections in the shock wave path. Next, 11 patients in whom subcostal BESWL was not feasible underwent intercostal BESWL. One patient complained of contact-site tenderness after BESWL, which resolved spontaneously. Transient elevations of aspartate aminotransferase occurred in two asymptomatic patients. Finally, both pathways were evaluated in 22 consecutive patients. Intercostal BESWL was the method of choice in only two patients. In each stage of the study all intercostally targeted gallstones fragmented. It is concluded that the intercostal pathway is a valid alternative whenever subcostal BESWL proves unsatisfactory.

Animals↗
PubMed1990

Iodinated contrast medium as an aid to gallstone dissolution with methyl tert-butyl ether: in vitro study.

Methyl tert-butyl ether (MTBE) floats on bile, whereas gallstones sink. Therefore, stones and MTBE are separated by a layer of bile. This study investigates the effect of contrast medium on flotation of gallstones in bile and its role in stone and fragment dissolution with MTBE. Fresh human gallstones, both calcified and noncalcified, from different patients were tested in vitro for flotation in bile, with and without addition of contrast medium. All gallstones or fragments sank in bile before the introduction of contrast medium. Noncalcified stones floated when the contrast medium-bile volume ratio was 1:6 or more, while double this amount of contrast medium was required to float calcified stones. Fragments did dissolve somewhat in MTBE in the presence of bile alone, but when contrast medium was added, almost complete dissolution occurred. This is thought to be due to increased contact between the fragments and MTBE, both floating on the contrast medium-bile mixture. Contrast material may be a useful adjuvant in gallstone dissolution therapy with MTBE in vivo.

Bile↗
PubMed1990

Extracorporeal shock wave lithotripsy of calcified gallstones. Work in progress.

Thirty-eight patients with calcific cholecystolithiasis underwent extracorporeal shock wave lithotripsy (ESWL) of the gallbladder on an outpatient basis. Twenty-two (60%) patients had fragments smaller than 3 mm on follow-up ultrasound (US) studies after an average of 13,450 shock waves and four lithotripsy sessions. Nineteen of these 22 patients were followed up for an average of 18 weeks, and only three were found to be free of residual fragments at US. The other three patients were lost to follow-up. Sixteen patients are still undergoing biliary ESWL. Comparison of calcified and noncalcified gallbladder calculi revealed that calcified stones required 50% more shock waves for successful fragmentation, fragments cleared considerably more slowly from the gallbladder, and patients had a higher frequency of acute pancreatitis (5% vs 2%) and transient hematuria (8% vs 3%). Stones with dense homogeneous calcification required significantly fewer shock waves for successful fragmentation than stones with calcific lamination. ESWL can be applied occasionally in patients with calcific cholecystolithiasis if an alternative to surgery is required, but success has been limited.

Calcinosis↗
PubMed1990

Extracorporeal cholecystolithotripsy without oral chemolitholysis.

One hundred thirty-six patients completed extracorporeal biliary lithotripsy (EBL) for symptomatic cholecystolithiasis. Sonographic evidence of complete clearance of all stone fragments was the only criterion for treatment success, which occurred in 32 of the 71 patients (45%) followed up for 24 weeks and in 36 of the 59 patients (61%) followed up for 52 weeks. The authors' protocol varied from protocols of other researchers primarily in that no adjuvant chemolitholysis was used. However, the number of treatment sessions and total number of shock waves (a maximum of 4,000 shock waves per treatment session, 12,000 shock waves in a patient demonstrating no significant fragmentation, and 20,000 shock waves in a patient whose stones responded well to fragmentation) was higher than those in other reports. The results of treatment and complication rates in this study are comparable with those at centers using both shock-wave lithotripsy and chemotherapy. The authors conclude that EBL is developing into an important alternative to surgery, which was obviated in all patients with complete clearance of fragments from the gallbladder.

Cholelithiasis↗
PubMed1990

Routine liver function tests and serum amylase determinations after biliary lithotripsy: are they necessary?

Shock-wave-induced soft-tissue damage after biliary extracorporeal shock-wave lithotripsy (BESWL) has been reported. Every patient treated in Vancouver has, therefore, had liver function tests and serum amylase levels measured before and within 6 days after BESWL. All patients had symptomatic cholecystolithiasis with normal pre-BESWL biochemistry. Analysis of 311 patients after treatment with the Siemens Lithostar unit showed elevation of one or more laboratory value in 19% (60/311). Serum aspartate transaminase level was most frequently abnormal (38 cases). The majority of abnormalities were mild, less than two times normal levels. Clinically significant complications occurred in five patients (three pancreatitis, one cholecystitis, one common bile duct obstruction); four of these occurred 1 week or more after treatment. The results of routine laboratory tests could not be used to predict complications. No correlation was seen between abnormal values and number of shock waves administered or peak shock-wave pressure. Of 112 patients surveyed at the time of post-BESWL enzyme measurement, 49 (44%) reported a degree of pain, which was severe in eight cases. Presence of severe pain correlated strongly (p less than .001) with abnormal laboratory findings, however not with the degree of abnormality. As results of these laboratory tests are nonspecific, have not been shown to correlate with the degree of severity of BESWL-induced tissue damage, and do not predict complications, the tests are of little value in the absence of clinical signs and symptoms. These conclusions, however, apply only to the Siemens Lithostar Plus with patients treated in the steep left posterior oblique position. Cost savings can be expected if routine post-BESWL biochemical tests are abandoned.

Adolescent↗
PubMed1990

Biliary lithotripsy with the Siemens Lithostar Plus overhead module.

A third shock head has been added to the Lithostar. This overhead module with integrated ultrasound complements the existing bilateral undertable shock heads with biplane x-ray amplifiers for stone targeting. Extracorporeal shock wave treatment of urinary tract stones, pancreatic stones, and stones in the gallbladder and bile ducts has thereby become possible in one true multipurpose lithotripter. Technical information and clinical experience in the biliary tract with the overhead module is presented.

Cholelithiasis↗