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Biomedical subjects

C Ell

Publications and source records attributed to C Ell.

At least 19 recordsLinked to original sources
PubMed1992

[The piezoelectric lithotripsy of gallstones. The acute- and long-term results].

Extracorporeal piezoelectric lithotripsy (PEL) with oral lysis (about 7.5 mg/kg urso- and chenodeoxycholic acid as single dose in the evening) was performed, according to a standardized treatment and follow-up protocol, in 219 patients (177 women, 42 men; aged 47 +/- 14 years) with symptoms of gallbladder stones. The average number of treatment sessions per patient was 2.0 +/- 0.8. Significantly fewer sessions with fewer shockwave charges were required in solitary gallstones of less than or equal to 20 mm diameter than in those of greater than 20 mm diameter and in multiple concrements (P less than 0.01). Fragmentation was successful in 99% of patients. Sedation and/or analgesia during PEL were required in only 2% of patients. There were no marked side effects during the treatment. The stone-free rate 12 months after the start of treatment was 76% in the group with solitary stones less than or equal to 20 mm, 75% with solitary stones greater than 20 mm and 64% for multiple stones. During the follow-up period 36% of patients had biliary colics and 3% had fragments impacted in the common bile duct. Biliary pancreatitis occurred in 1% of patients. PEL is an effective and sparing procedure in the treatment of selected patients with gallbladder stones.

Adult↗
PubMed1992

[Laser lithotripsy in gastroenterology].

Almost 90% of all stones in the bile duct can be removed after sphincterotomy and additional mechanical or electrohydraulic lithotripsy. However, a small number of very large or very hard or impacted stones remain, which cannot be removed by conventional endoscopic methods. Intracorporeal laser-induced lithotripsy is a new, promising method to improve stone clearance rate in the common bile duct and--in special cases--also of the pancreatic duct system. Laser-induced lithotripsy especially in combination with a stone tissue detection system is a safe and effective method which can be performed either under direct endoscopic vision or--in selected cases--under X-ray control alone.

Cholelithiasis↗
PubMed1992

[Contact litholysis and contact lithotripsy of symptomatic biliary calculi].

Contact litholysis and lithotripsy are invasive methods of gallstone destruction, since the gallbladder must necessarily be approached by the transhepatic or transperitoneal routes or through Oddi's sphincter. Both methods expose to complications which may require a corrective operation. The risk of recurrence is the same as with extracorporeal lithotripsy. Unless proved otherwise by further clinical trials, in the future these experimental methods should be used in a very small number of patients.

Cholelithiasis↗
PubMed1992

Shockwave lithotripsy of salivary duct stones.

Surgical extirpation of the affected gland has been necessary for cases of sialolithiasis in which the stone cannot be removed by dilatation or dissection of the salivary duct. The ability of the piezoelectric lithotripter to deliver shockwaves to a small focus makes extracorporeal shockwave lithotripsy of salivary gland stones potentially safe. Its safety and efficacy have been assessed in 51 patients with symptomatic solitary salivary stones that could not be removed by conservative measures. The stones had a median diameter of 8 (range 4-18) mm and were located in the submandibular gland in 69% of patients and in the parotid gland in 31%. A total of 72 shockwave treatment sessions (maximum 3 per patient) were given under continuous sonographic monitoring. In 45 patients (88%) complete fragmentation (fragments less than or equal to 3 mm) of the concrements was achieved. No patient needed anaesthesia, sedatives, or analgesics. The only untoward effects were localised petechial haemorrhages after 10 (13%) out of 72 treatments and transient swelling of the gland immediately after delivery of shockwave in 2/72 (3%) sessions. 20 weeks after the first session 90% (46/51) of patients were free of discomfort, and 53% (27/51) were stone free. Stone-clearance rate was higher among patients with stones in the parotid gland (81%) than among those with stones of the submandibular gland (40%). Auxiliary measures such as dilatation or dissection of the salivary duct were required only in patients with stones in the submandibular gland (20%). No long-term damage to the treated salivary gland or to adjacent tissue structures was noted during the median follow-up of 9 (1-24) months. Extracorporeal piezoelectric shockwave therapy seems likely to be safe, comfortable, and effective minimally-invasive, non-surgical treatment for salivary stones.

Adolescent↗
PubMed1992

Pain in extracorporeal shock-wave lithotripsy: a comparison of different lithotripters in volunteers.

The aim of the present study was to investigate pain sensations experienced during extracorporeal shock-wave application, comparing an electrohydraulic (MPL 9000; Dornier Medizintechnik, Germering, Germany), an electromagnetic (Lithostar Plus; Siemens, Erlangen, Germany), and a piezoelectric (Piezolith 2300; Wolf, Knittlingen, Germany) shock-wave system. In nine healty volunteers, three therapeutically used intensities were applied in a randomized order with each lithotripter (MPL 9000: 16, 20, and 24 kV; Lithostar Plus: settings 5, 7, and 9; and Piezolith 2300: settings 2, 3, and 4). The subjects received nine series of 20 shock waves amounting to a total of 180 shock waves per session. The treatment was performed under clinical conditions, and no premedication was given. A visual analog scale and the McGill Pain Questionnaire were used for assessment of pain. In addition, somatosensory evoked potentials caused by shock-wave stimulation were recorded. Some of the volunteers were unable to bear the pain caused by the highest shock-wave intensity of the electrohydraulic (n = 3) and the electromagnetic system (n = 4). Estimates using the visual analogue scale showed increased pain sensations with increasing energy settings for each lithotripter. The amplitudes of the somatosensory evoked potentials became larger, and latencies shortened with increasing stimulus intensities (P less than 0.05). Subjective estimates by means of the visual analogue scale (P less than 0.01) as well as the McGill Pain Questionnaire (NS) and the somatosensory evoked potentials (P less than 0.05) showed that stimulation by the piezoelectric lithotripter was less painful than stimulation by the two other generators.

Adult↗
PubMed1992

Extracorporeal piezoelectric shock-wave lithotripsy of salivary gland stones.

Piezoelectric lithotripsy was undertaken on 19 patients with salivary stones, with none of these patients requiring anesthesia, analgetics, or sedatives. All salivary stones were totally fragmented during first lithotripsy. Four months after treatment with extracorporeal shock waves, all patients were free of symptoms and, in 11 of the patients, no calculi could be found sonographically. The piezoelectric lithotripsy of salivary stones caused no serious side effects which could be proven by clinical, biochemical, sonographic, and magnetic resonance imaging (MRI) examinations. Extracorporeal piezoelectric lithotripsy is a new and promising nonsurgical therapy for selected cases of sialolithiasis of the parotid and submandibular glands.

Adult↗
PubMed1991

[Imaging procedures prior to the extracorporeal shockwave lithotripsy of gallstones].

In order to determine whether cholecystography and computed tomography (CT) are capable of better gallstone characterization than conventional radiography alone, 91 patients (76 females, 15 males; mean age 47 +/- 12 years) with symptomatic single gallstones were studied prospectively prior to extracorporeal shock-wave lithotripsy with concomitant oral stone dissolution therapy. In addition, the value of oral cholecystography in demonstrating patency of the cystic duct was compared with ultrasound assessment of gallbladder function. Despite "negative" plain gallbladder radiographs in all patients, oral cholecystography showed significant stone calcification in 8 of the 91 patients and CT showed stone calcifications in 52 of the 91 patients. In 12 patients the maximum stone density was between 50 and 90 Hounsfield units, and in 40 patients it was more than 90 Hounsfield units. CT revealed ring-like calcification in the majority (79%) of these stones. Oral cholecystography showed satisfactory concentration of contrast medium in all patients, while ultrasonography of the gallbladder following a chemically defined test meal demonstrated contractility of more than 50% of initial volume in 69 patients and of less than 30% in 9 patients. Although oral cholecystography is a simple, readily available complication-free method, ultrasound assessment of gallbladder contraction is better for selecting patients for extracorporeal shock-wave lithotripsy. CT allows significantly better characterization of gallstones than oral cholecystography and conventional plain gallbladder radiography.

Adult↗
PubMed1991

Lithotripsy of gallstones by means of a quality-switched giant-pulse neodymium:yttrium-aluminum-garnet laser. Basic in vitro studies using a highly flexible fiber system.

The quality-switched neodymium:yttrium-aluminum-garnet laser represents a new instrument for athermal fragmentation of gallstones by transformation of optical energy into mechanical energy in the form of shock waves via local plasma formation. A highly flexible 300-micron fiber transmission system was used in basic investigations to determine the influence of varying pulse repetition rates (5-30 Hz) and pulse energies (15 and 20 mJ) on shock wave intensity and stone fragmentation in vitro for 105 biliary calculi of known size and chemical composition. After performance of 1200 shock wave pressure measurements using polyvinylidenefluoride hydrophones, stone fragmentation was analyzed by determination of fragment removal rates (volume of fragments removed per fragmentation time), ablation rates (mean volume removed per laser pulse), and median fragment sizes for each laser setting. With the quality-switched neodymium:yttrium-aluminum-garnet laser system, all concrements could be reliably disintegrated into small fragments (median diameter, 0.7-1.7 mm). Compared with pure cholesterol stones, a significantly higher fragment removal rate was achieved in cholesterol stones containing 30% calcium phosphate (P = 0.039), in cholesterol stones containing 20% pigment (P = 0.015), and in pure pigment stones (P = 0.007). Fragment removal rates, local shock wave pressures, and median grain sizes were significantly higher at a pulse energy of 20 mJ than with 15 mJ. Shock wave pressures showed a distinct dependence on pulse repetition rates at 20 mJ, yet not at 15 mJ. Because there is no evident hazard of thermal damage to tissue using the quality-switched neodymium:yttrium-aluminum-garnet laser, it appears to be a promising device for nonsurgical biliary stone therapy.

Aluminum↗
PubMed1991

Significance of computed tomography for shock-wave therapy of radiolucent gallbladder stones.

One hundred eleven symptomatic patients (91 women, 20 men) with solitary "radiolucent" stones (proved by a plain radiograph) underwent examination with computed tomography for stone analysis before extracorporeal shock-wave lithotripsy with a second-generation piezoelectric lithoptripter. The aim of the study was to assess the importance of computed tomography as a diagnostic pretreatment procedure compared with the plain abdominal radiograph: computed tomography density values greater than 50 Hounsfield units (HU) were found in 64 of 111 patients with radiolucent stones (58%). Of these 64, 50 patients even had values greater than 90 HU (50/111;45%). The majority of the stones with density values greater than 50 HU had a hyperdense rim (43 of 64) with a mean maximum attenuation of 134 +/- 68 HU. A significantly higher degree of stone disintegration was achieved with stones of group A (less than or equal to 50 HU) than with those in group B (greater than 50 HU and less than or equal to 90 HU) and group C (greater than 90 HU) with respect to the mean maximum fragment size after the first (P less than 0.001) and last (P less than 0.01) lithotripsy and with respect to the total number of shock waves applied (P less than 0.001) and the number of treatments (P less than 0.001). No difference was observed between groups B and C. After all follow-up periods, the rate of complete stone disappearance was higher in group A than in group B (NS for 1, 2, and 4 months of follow-up; P less than 0.01 for month 8; P less than 0.05 for month 12) and group C (P less than 0.05 for 1, 2, and 4 months of follow-up; P less than 0.001 for months 8 and 12). The authors conclude that computed tomographic analysis of gallstones before lithotripsy is more sensitive in detecting nonradiolucent stones than in the plain radiograph. Computed tomographic stone analysis seems to provide a better selection of patients suitable for biliary lithotripsy and could become a standard diagnostic pretreatment procedure to improve stone disintegration and complete stone disappearance after shock-wave lithotripsy and adjuvant chemolitholysis.

Adult↗
PubMed1991

[Laser lithotripsy of ureteral stones. Personal experiences].

The in vitro evaluation of a pulsed Nd:YAG laser, showed an effective and fine fragmentation of urinary calculi and showed only minimal subepithelial bleeding in the directly irradiated canine ureter. Since 1989 we have treated ureteral calculi in 30 patients. The laser pulses of 15-20 mJ (at fiber tip), 20 ns, 20-25 cps are transmitted by a 300-microns quartz fiber with a specially formed tip focusing the light. The fiber is passed through an 11.5-F ureteroscope within a guide tube, or, without a guide tube, through one of the new minimized ureteroscopies and is placed in front of the calculus. In 27 patients the procedure was successful, without any residual concretions after 1 day. In our opinion the advantages of this method are the very fine-grained, complete fragmentation of all sorts of calculi, the highly atraumatic procedure, and the absence of either optical or acoustic irritation to the operator.

Adult↗
PubMed1991

[The laser in gastroenterology].

The use of lasers in gastroenterology is an enrichment of the non-invasive therapeutic methods. Prerequisite is their critical use which, in order to be successful, needs a minimum frequency and thus experience. In form of a strictly constructed survey the paper deals with the potential possibilities of laser application and with the alternative approaches being today at our disposal.

Endoscopes, Gastrointestinal↗