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J M Teichman

Publications and source records attributed to J M Teichman.

At least 37 records · Page 2Linked to original sources
PubMed1999

Holmium: YAG lithotripsy: photothermal mechanism.

OBJECTIVE: A series of experiments were conducted to test the hypothesis that the mechanism of holmium:YAG lithotripsy is photothermal. METHODS AND RESULTS: To show that holmium:YAG lithotripsy requires direct absorption of optical energy, stone loss was compared for 150 J Ho:YAG lithotripsy of calcium oxalate monohydrate (COM) stones for hydrated stones irradiated in water (17+/-3 mg) and hydrated stones irradiated in air (25+/-9 mg) v dehydrated stones irradiated in air (40+/-12 mg) (P < 0.001). To show that Ho:YAG lithotripsy occurs prior to vapor bubble collapse, the dynamics of lithotripsy in water and vapor bubble formation were documented with video flash photography. Holmium:YAG lithotripsy began at 60 microsec, prior to vapor bubble collapse. To show that Ho:YAG lithotripsy is fundamentally related to stone temperature, cystine, and COM mass loss was compared for stones initially at room temperature (approximately 23 degrees C) v frozen stones ablated within 2 minutes after removal from the freezer. Cystine and COM mass losses were greater for stones starting at room temperature than cold (P < or = 0.05). To show that Ho:YAG lithotripsy involves a thermochemical reaction, composition analysis was done before and after lithotripsy. Postlithotripsy, COM yielded calcium carbonate; cystine yielded cysteine and free sulfur; calcium hydrogen phosphate dihydrate yielded calcium pyrophosphate; magnesium ammonium phosphate yielded ammonium carbonate and magnesium carbonate; and uric acid yielded cyanide. To show that Ho:YAG lithotripsy does not create significant shockwaves, pressure transients were measured during lithotripsy using needle hydrophones. Peak pressures were <2 bars. CONCLUSION: The primary mechanism of Ho:YAG lithotripsy is photothermal. There are no significant photoacoustic effects.

Analysis of Variance↗
PubMed1999

Holmium: YAG lithotripsy: optimal power settings.

PURPOSE: We tested the hypothesis that holmium:YAG laser lithotripsy speed is best maximized by using low pulse energy at high pulse frequency. MATERIALS AND METHODS: To demonstrate that optical fiber damage increases with pulse energy and irradiation, the 365-microm optical fiber irradiated calcium hydrogen phosphate dihydrate (CHPD), calcium oxalate monohydrate (COM), cystine, magnesium ammonium phosphate hexahydrate (MAPH), and uric acid calculi at pulse energies of 0.5 to 2.0 J. Optical energy output was measured with an energy detector after 10 J to 200 J of total energy. To demonstrate that lithotripsy efficiency varies with power, fragmentation was measured at constant power settings at total energies of 200 J and 1 kJ with the 365-microm optical fiber. Fragmentation was measured for the 272-microm optical fiber at pulse energies of 0.5 J to 1.5 J at 10 Hz. To demonstrate that low pulse energy produces smaller fragments than high pulse energy, fragment size was characterized for COM and uric acid calculi after 0.25 kJ of irradiation using the 272-microm to 940-microm optical fibers at 0.5 J to 1.5 J. RESULTS: Damage to the 365-microm optical fiber was greatest for irradiation of CHPD, followed by MAPH, and COM (P<0.001). There was no significant optical fiber damage after cystine and uric acid lithotripsy. For the 365-microm optical fiber and CHPD, fragmentation after 200 J was greatest for pulse energies < or =1.0 J (P< 0.001). For other compositions, fragmentation was not statistically different among the power settings for constant irradiation. No significant difference was noted in fragmentation for any composition at different pulse energies (1.0 v. 2.0 J) for 1-kJ irradiation. However, for all compositions, the calculated lithotripsy speed was greatest at high power settings (P<0.001). For the 272-microm optical fiber, CHPD fragmentation was greatest for the 1.0-J pulse energy. The mean fragment size and relative quantity of fragments > or =2 mm both increased as pulse energy increased. CONCLUSIONS: Optical fiber degradation varies with stone composition, irradiation, and pulse energy. Holmium:YAG lithotripsy speed is maximized with higher power (either increased pulse energy or higher pulse frequency). Because low pulse energy may be safer and yields smaller fragments than high pulse energy, holmium:YAG lithotripsy speed is best increased by using pulse energies < or =1.0 J at a high repetition rate.

Calcium Oxalate↗
PubMed1999

Color vision deficits and laser eyewear protection for soft tissue laser applications.

PURPOSE: Laser safety considerations require urologists to wear laser eye protection. Laser eye protection devices block transmittance of specific light wavelengths and may distort color perception. We tested whether urologists risk color confusion when wearing laser eye protection devices for laser soft tissue applications. MATERIALS AND METHODS: Subjects were tested with the Farnsworth-Munsell 100-Hue Test without (controls) and with laser eye protection devices for carbon dioxide, potassium titanyl phosphate (KTP), neodymium (Nd):YAG and holmium:YAG lasers. Color deficits were characterized by error scores, polar graphs, confusion angles, confusion index, scatter index and color axes. Laser eye protection device spectral transmittance was tested with spectrophotometry. RESULTS: Mean total error scores plus or minus standard deviation were 13+/-5 for controls, and 44+/-31 for carbon dioxide, 273+/-26 for KTP, 22+/-6 for Nd:YAG and 14+/-8 for holmium:YAG devices (p <0.001). The KTP laser eye protection polar graphs, and confusion and scatter indexes revealed moderate blue-yellow and red-green color confusion. Color axes indicated no significant deficits for controls, or carbon dioxide, Nd:YAG or holmium:YAG laser eye protection in any subject compared to blue-yellow color vision deficits in 8 of 8 tested with KTP laser eye protection (p <0.001). Spectrophotometry demonstrated that light was blocked with laser eye protection devices for carbon dioxide less than 380, holmium:YAG greater than 850, Nd:YAG less than 350 and greater than 950, and KTP less than 550 and greater than 750 nm. CONCLUSIONS: The laser eye protection device for KTP causes significant blue-yellow and red-green color confusion. Laser eye protection devices for carbon dioxide, holmium:YAG and Nd:YAG cause no significant color confusion compared to controls. The differences are explained by laser eye protection spectrophotometry characteristics and visual physiology.

Adult↗
PubMed1999

Urological needs assessment for primary care practice: implications for undergraduate medical education.

PURPOSE: The majority of graduating medical students will become primary care physicians. We discuss what urological topics primary care physicians need to know, proficiency in urological skills of primary care physicians and undergraduate urological curriculum recommendations that would serve the needs of primary care physicians. MATERIALS AND METHODS: A written survey instrument was mailed to all 452 family practice residency directors in the United States. Subjects rated how well family practice physicians need to know urological topics and how proficient they must be in urological skills. RESULTS: A total of 329 responses were received (response rate 73%). Respondents indicated that they need to know urinary tract infection, sexually transmitted disease, epididymitis, benign prostatic hyperplasia diagnosis, hematuria and erectile dysfunction diagnosis very well. They indicated a greater need to know diagnostics than staging or management of prostate, bladder, renal or testis cancer (p <0.05). Among diagnostics respondents indicated that generalists should be highly proficient in urinalysis interpretation. Proficiency was ranked greater for interpretations of semen analysis than excretory urogram, abdominal computerized tomography or magnetic resonance imaging, or renal ultrasound (p <0.05). Proficiency in catheter insertion and circumcision was ranked highly, and vasectomy was ranked moderately. CONCLUSIONS: Primary care physicians need to know and be proficient in many urological topics and skills. They need to know diagnostics better than staging and management information, and urological infectious topics better than urological cancers. They need to be proficient in physical examination, urinalysis interpretation, catheter insertion, circumcision and vasectomy. Undergraduate medical education should reflect these needs.

Clinical Competence↗
PubMed1999

Potassium leak test predicts outcome in interstitial cystitis.

PURPOSE: We tested whether the potassium leak test predicts the outcome of therapy with heparinoids and antidepressants in interstitial cystitis. MATERIALS AND METHODS: We retrospectively reviewed the records of 38 evaluable patients with interstitial cystitis who underwent a potassium leak test at the initial evaluation and who were treated intravesically with heparin or oral sodium pentosan polysulfate for a minimum of 6 months. All but 1 patient were also treated with tricyclic antidepressants. Changes in average pain score during voiding, urinary frequency and nocturia were evaluated. RESULTS: The potassium leak test was positive and negative in 23 and 15 patients, respectively. There was no significant difference in the 2 groups at baseline in regard to the male-to-female ratio, patient age, years of symptoms, pain score, urinary frequency, nocturia or anesthetic capacity. After a minimum of 6 months of therapy patients in whom the potassium leak test was positive were more likely to have improvement than those in whom it was negative, as shown by a decrease of greater than 25% in pain score (78 versus 40%, p = 0.01), frequency (83 versus 47%, p = 0.02) and nocturia (83 versus 53%, p = 0.05). However, potassium leak test results showed no significant difference at the 50% decrease level in pain score, frequency or nocturia. CONCLUSIONS: The potassium leak test may predict outcome in patients with interstitial cystitis who are treated with combined heparinoid and tricyclic antidepressant medication.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1999

Proteus mirabilis viability after lithotripsy of struvite calculi.

PURPOSE: We tested the hypotheses that Proteus mirabilis viability of struvite calculi differs after exposure to different lithotripsy modalities and that the photothermal mechanism of holmium:YAG lithotripsy is antibacterial. MATERIALS AND METHODS: Human calculi of known struvite composition (greater than 90% magnesium ammonium phosphate hexohydrate) were incubated with P. mirabilis. Calculi were randomly distributed and fragmented with no lithotripsy (controls), or shock wave, intracorporeal ultrasonic, electrohydraulic, pneumatic, holmium:YAG or pulsed dye laser lithotripsy. After lithotripsy fragments were sonicated and specimens were serially plated for 48 hours at 38C. Bacterial counts and the rate of bacterial sterilization were compared. RESULTS: Median bacterial counts (colony-forming units per ml.) were 8 x 10(6) in controls and 3 x 10(6) in shock wave, 3 x 10(7) in ultrasonic, 4 x 10(5) in electrohydraulic, 8 x 10(6) in pneumatic, 5 x 10(4) in holmium:YAG and 1 x 10(6) in pulsed dye laser lithotripsy cases (p <0.001). The rate of bacterial sterilization was 50% for holmium:YAG lithotripsy treated stones versus 0% for each of the other cohorts (p <0.01). CONCLUSIONS: P. mirabilis viability varies among lithotrites. The photothermal mechanism of holmium:YAG lithotripsy is antibacterial.

Humans↗
PubMed1998

Holmium:YAG lithotripsy: photothermal mechanism converts uric acid calculi to cyanide.

PURPOSE: Holmium:YAG lithotripsy fragments stones through a photothermal mechanism. Uric acid when heated is known to be converted into cyanide. We test the hypothesis that holmium: YAG lithotripsy of uric acid calculi produces cyanide. MATERIALS AND METHODS: Human calculi of known uric acid composition were irradiated with holmium:YAG energy in water. Stones received a total holmium:YAG energy of 0 (control), 0.1, 0.25, 0.5, 0.75, 1.0 or 1.25 kJ. The water in which lithotripsy was performed was analyzed for cyanide concentration. A graph was constructed to relate holmium:YAG energy to cyanide production. RESULTS: Holmium:YAG lithotripsy of uric acid calculi in vitro produced cyanide consistently. Cyanide production correlated with total holmium:YAG energy (p <0.001). CONCLUSIONS: Holmium:YAG lithotripsy of uric acid calculi risks production of cyanide. This study raises significant safety issues.

Aluminum Silicates↗
PubMed1998

Holmium:YAG lithotripsy efficiency varies with energy density.

PURPOSE: We test the hypothesis that holmium:YAG lithotripsy efficiency varies with optical fiber size and energy settings (energy density). MATERIALS AND METHODS: The 272, 365, 550 and 940 microm. optical fibers delivered 1 kJ. total holmium:YAG energy to calcium oxalate monohydrate calculi at energy output/pulse of 0.2 to 1.5 J. Stone mass loss was measured for each fiber energy setting. Stone crater width was characterized for single energy pulses. Fiber energy outputs were compared before and after lithotripsy. RESULTS: Stone mass loss correlated inversely with optical fiber diameter (p <0.05). Stone loss correlated with energy/pulse for the 365, 550 and 940 microm. fibers (p <0.001). The 272 and 365 microm. fibers yielded equivalent stone loss at 0.2 and 0.5 J. per pulse. At energies of 1.0 J. per pulse or greater the 272 microm. optical fiber was prone to damage, and yielded reduced energy output and stone loss compared to the 365 microm. fiber (p <0.01). Stone crater width for single pulse energies correlated with energy settings for all fibers (p <0.001). CONCLUSIONS: Lithotripsy efficiency with the holmium:YAG laser depends on pulse energy output and diameter of the optical delivery fiber, implying that lithotripsy efficiency correlates with energy density. The 365 microm. fiber is indicated for most lithotripsy applications. The 272 microm. fiber is susceptible to damage and inefficient energy transmission at energies of 1.0 J. per pulse or greater. The 272 microm. fiber is indicated at energies of less than 1.0 J. per pulse for small caliber ureteroscopes or when maximal flexible ureteroscope deflection is required.

Aluminum Silicates↗
PubMed1998

Holmium:YAG percutaneous nephrolithotomy: the laser incident angle matters.

PURPOSE: Laser physics dictate that maximal radiant exposure occurs when the laser strikes the target at a normal incidence. Since the renal collecting system often limits nephroscope movements during percutaneous nephrolithotomy, the laser-calculus incidence angle may vary. We have observed during holmium:YAG percutaneous nephrolithotomy that the side firing fiber more easily approaches a normal incidence compared to the end firing fiber. We test the hypothesis that holmium:YAG percutaneous nephrolithotomy is faster with a side firing fiber compared to an end firing fiber. MATERIALS AND METHODS: Consecutive holmium:YAG percutaneous nephrolithotomy cases were studied retrospectively. The calculus size and composition, surgical time, fragmentation speed (size/time) and stone-free rates were compared between 11 patients treated with end and 8 treated with side firing fibers. RESULTS: When the end and side firing groups were compared, calculus sizes (mean plus or minus standard deviation) were 22 +/- 13 versus 48 +/- 17 mm. (p = 0.004), calcium oxalate monohydrate incidence was 55 versus 75% (p = 0.3), surgical times were 168 +/- 87 versus 124 +/- 51 minutes, computed fragmentation speeds were 0.15 +/- 0.09 versus 0.43 +/- 0.15 mm. per minute (p = 0.0009) and stone-free rates were 73 versus 88% (p = 0.4), respectively. CONCLUSIONS: The side firing fiber is faster than the end firing fiber for holmium:YAG percutaneous nephrolithotomy. These results are consistent with principles of laser physics.

Aluminum↗
PubMed1998

Holmium:YAG lithotripsy yields smaller fragments than lithoclast, pulsed dye laser or electrohydraulic lithotripsy.

PURPOSE: The mechanism of lithotripsy differs among electrohydraulic lithotripsy, mechanical lithotripsy, pulsed dye lasers and holmium:YAG lithotripsy. It is postulated that fragment size from each of these lithotrites might also differ. This study tests the hypothesis that holmium:YAG lithotripsy yields the smallest fragments among these lithotrites. MATERIALS AND METHODS: We tested 3F electrohydraulic lithotripsy, 2 mm. mechanical lithotripsy, 320 microns pulsed dye lasers and 365 microns. holmium:YAG fiber on stones composed of calcium hydrogen phosphate dihydrate, calcium oxalate monohydrate, cystine, magnesium ammonium phosphate and uric acid. Fragments were dessicated and sorted by size. Fragment size distribution was compared among lithotrites for each composition. RESULTS: Holmium:YAG fragments were significantly smaller on average than fragments from the other lithotrites for all compositions. There were no holmium:YAG fragments greater than 4 mm., whereas there were for the other lithotrites. Holmium:YAG had significantly greater weight of fragments less than 1 mm. compared to the other lithotrites. CONCLUSIONS: Holmium:YAG yields smaller fragments compared to electrohydraulic lithotripsy, mechanical lithotripsy or pulsed dye lasers. These findings imply that fragments from holmium:YAG lithotripsy are more likely to pass without problem compared to the other lithotrites. Furthermore, the significant difference in fragment size adds evidence that holmium:YAG lithotripsy involves vaporization.

Calculi↗
PubMed1998

Holmium:yttrium-aluminum-garnet lithotripsy efficiency varies with stone composition.

OBJECTIVES: To test the hypothesis that holmium:yttrium-aluminum-garnet (YAG) lithotripsy efficiency varies with stone composition. METHODS: Single pulses of holmium:YAG energy were delivered using 272-, 365-, 550-, and 940-microm optical fibers to human calculi composed of calcium oxalate monohydrate (COM), calcium hydrogen phosphate dihydrate (CHPD), cystine, magnesium ammonium phosphate hexohydrate (MAPH), and uric acid. Energy/pulse settings were 0.2, 0.5, 1.0, and 1.5 J. Stone crater width and depth were characterized with reflectance light microscopy. RESULTS: For similar energies overall MAPH yielded the deepest and widest craters. CHPD, cystine, and uric acid yielded craters of intermediate width and depth. COM yielded the smallest craters. Within any given composition, increased pulse energy yielded craters of increased width and depth. CONCLUSIONS: Holmium:YAG lithotripsy efficiency varies with stone composition. The rank order of crater size appears to correlate with thermal threshold for each composition. Increased holmium:YAG energy produces larger craters for all compositions.

Humans↗
PubMed1998

Malone antegrade continence enemas for autonomic dysreflexia secondary to neurogenic bowel.

A 42-year-old man with T-4 ASIA B thoracic paraplegia presented with chronic constipation, fecal incontinence, and bowel-related autonomic dysreflexia (AD) refractory to conservative bowel program. His usual toileting time lasted one to five hours. Antegrade continence enemas (ACE) were performed. The ACE technique, which requires creating a continent catheterizable appendicocecostomy, is described. Postoperatively, a daily enema was given through the stoma. The patient's toileting time was reduced to 20 minutes and his AD resolved. The role of the ACE is discussed in adult spinal cord injury (SCI).

Adult↗
PubMed1998

Color vision deficits during laser lithotripsy using safety goggles for coumarin green or alexandrite but not with holmium:YAG laser safety goggles.

PURPOSE: Laser lithotripsy requires urologists to wear laser eye protection. Laser eye protection devices screen out specific light wavelengths and may distort color perception. This study tests whether urologists risk color confusion when wearing laser eye protection devices for laser lithotripsy. MATERIALS AND METHODS: Urologists were tested with the Farnsworth Dichotomous Test for Color Blindness (D-15) and the Farnsworth-Munsell 100-Hue Test (FM-100) without (control) and with laser eye protection devices for coumarin green, alexandrite and holmium:YAG lasers. Error scores were tabulated. The pattern of color deficits was characterized with confusion angles, confusion index (C-index), scatter index (S-index) and color axes. Laser eye protection devices were tested with spectrophotometry for spectral transmittance and optical density. RESULTS: The D-15 transposition errors (mean plus or minus standard deviation) for control, holmium:YAG, alexandrite and coumarin green laser eye protection were 0 +/- 0, 0 +/- 0, 0.3 +/- 0.5 and 6.4 +/- 1.6, respectively (p = 0.0000001). The FM-100 error scores (mean plus or minus standard deviation) were 20 +/- 15, 20 +/- 14, 91 +/- 32 and 319 +/- 69, respectively (p = 0.0001). The confusion index scores indicated a mild color confusion for the alexandrite and pronounced color confusion for the coumarin green laser eye protection. The confusion angles and scatter indexes mimicked a congenital blue-yellow deficit for coumarin green laser eye protection. Color axes showed no significant deficits for control or holmium:YAG laser eye protection in any subject, red-green axis deficits in 3 of 6 tested with alexandrite and blue-yellow axis deficits in 12 of 12 tested with coumarin green (p < 0.001). Spectrophotometry showed that laser eye protection for coumarin green blocks light less than 550 nm., alexandrite blocks light greater than 650 nm. and holmium:YAG blocks light greater than 825 nm. CONCLUSIONS: Laser eye protection for coumarin green causes pronounced blue-yellow color confusion, whereas alexandrite causes mild red-green color confusion among urologists, holmium:YAG causes no significant color confusion compared to controls. The differences are explained by laser eye protection spectrophotometry characteristics and visual physiology.

Adult↗
PubMed1998

Role and long-term results of laparoscopic decortication in solitary cystic and autosomal dominant polycystic kidney disease.

PURPOSE: Access to retroperitoneal structures via the laparoscope has become established for various conditions. This minimally invasive approach has distinct advantages over conventional open surgery. We document our experience with laparoscopic cyst decortication for diseases of the kidney, including simple and complex cysts, multiple cysts and autosomal dominant polycystic kidney disease. MATERIALS AND METHODS: We retrospectively reviewed the records of 17 patients who underwent a total of 20 procedures. Cases were categorized as polycystic kidney disease and nonpolycystic kidney disease. Factors analyzed were estimated blood loss, length of surgical procedure, hospital stay and complications. Followup included radiographic studies (computerized tomography and/or renal sonography) and patient subjective pain relief, as determined by clinical records and telephone interview. RESULTS: Nine and 11 procedures were done for nonpolycystic kidney disease and polycystic kidney disease, respectively. Of the 8 patients with polycystic kidney disease 3 underwent repeat procedures. Followup was 3 to 63 months (average 26). All patients with simple cysts who were treated for pain were pain-free at the latest followup. Of the 10 procedures 9 (90%) performed for pain relief in polycystic kidney disease successfully produced immediate pain relief. Pain-free status decreased with time with 7 of 8 (87.5%) pain-free after 6 months, and 5 of 7 (71.4%) at 1, 4 of 6 (66.7%) at 2 and 1 of 4 (25%) at 3 years. A repeat operation successfully relieved recurrent pain in 2 of 3 cases (66.7%). Of the 7 patients with polycystic kidney disease who underwent surgery for pain relief 5 (71%) are currently pain-free. CONCLUSIONS: Laparoscopic renal cyst decortication is an effective minimally invasive treatment for painful simple cysts. It is also effective for short to intermediate pain relief in autosomal dominant polycystic kidney disease. Long-term followup suggests that a repeat procedure may be necessary to maintain adequate control of symptoms in polycystic kidney disease.

Adult↗
PubMed1998

Malone antegrade continence enema for adults with neurogenic bowel disease.

PURPOSE: We describe the outcomes of adults with neurogenic bowel disease who underwent a Malone antegrade continence enema procedure with or without concomitant urinary diversion. MATERIALS AND METHODS: Consecutive adult patients with neurogenic bowel disease who underwent an antegrade continence enema procedure (continent catheterizable appendicocecostomy for fecal impaction) were retrospectively reviewed. RESULTS: Of the 7 patients who underwent an antegrade continence enema synchronous urinary procedure (ileal conduit, augmentation ileocystoplasty with continent catheterizable abdominal stoma or augmentation ileocystoplasty) was also performed in 6. Mean patient age was 32 years and mean followup was 11 months. Of the 7 patients 6 who self-administered antegrade continence enemas regularly were continent of stool per rectum and appendicocecostomy, using the appendicocecostomy as the portal for antegrade enemas. All 6 compliant patients reported decreased toileting time and improved quality of life. Preoperative autonomic dysreflexia resolved postoperatively in 3 patients. All urinary tracts were stable. In 4 patients 5 complications occurred, including antegrade continence enema stomal stenosis requiring appendicocutaneous revision (1), antegrade continence enema stomal stenosis requiring dilation (1), superficial wound infection (1), small bowel obstruction requiring lysis of adhesions (1) and urinary incontinence (1 who underwent continent urinary diversion). CONCLUSIONS: Patients with neurogenic bladder and bowel disease may benefit from antegrade continence enema performed synchronously with a urinary procedure. Antegrade continence enema may be indicated alone for neurogenic bowel. Patient selection is important.

Adult↗
PubMed1998

Holmium:YAG lithotripsy of uric acid calculi.

PURPOSE: Holmium:YAG lithotripsy of uric acid calculi produces cyanide. We review our experience with holmium:YAG lithotripsy of uric acid calculi to determine if there is any clinical evidence of cyanide toxicity. MATERIALS AND METHODS: A retrospective analysis of all of our cases of holmium:YAG lithotripsy of uric acid calculi was done. Anesthetic and postoperative data were reviewed. RESULTS: A total of 18 patients with uric acid calculi were treated with holmium:YAG lithotripsy by ureteroscopy (5), retrograde nephroscopy (2), percutaneous nephrolithotomy (5) or cystolithotripsy (6). No patient had increased end-tidal carbon dioxide, changes in electrocardiogram or significant decrease in postoperative serum bicarbonate. An 84-year-old woman had decreased diastolic pressure of 30 mm. Hg while under general anesthesia. No cyanide related neurological, cardiac or respiratory complications were noted. CONCLUSIONS: There were no obvious cyanide related complications from holmium:YAG lithotripsy of uric acid calculi. These data suggest no significant cyanide toxicity from holmium:YAG lithotripsy of uric acid calculi in typical clinical settings. Animal studies are warranted to characterize the risk.

Adolescent↗
PubMed1997

Ureteroscopic management of ureteral calculi: electrohydraulic versus holmium:YAG lithotripsy.

PURPOSE: This study compared electrohydraulic and holmium:YAG lithotripsy for ureteral calculi. MATERIALS AND METHODS: Two cohorts of consecutive patients with ureteral calculi treated with ureteroscopic electrohydraulic or holmium:YAG lithotripsy were retrospectively compared. Electrohydraulic lithotripsy was done using a 1.9F fiber at energy settings between 50 and 100 v. Holmium:YAG lithotripsy was done using a 365 microm. fiber at energy settings of 0.6 to 1.5 J. RESULTS: A total of 23 and 47 consecutive patients underwent electrohydraulic and holmium:YAG lithotripsy, respectively. For preoperative calculi less than 15 mm. mean stone size plus or minus standard deviation was 9 +/- 3 versus 9 +/- 3 mm. (p = 0.5), mean operative time was 72 +/- 21 versus 102 +/- 38 minutes (p = 0.004), stone-free rate at the end of ureteroscopy was 65 versus 97 (p < 0.01) and 3-month stone-free rate was 94 versus 97% (p = 0.4) for electrohydraulic versus holmium:YAG lithotripsy. For preoperative calculi 15 mm. or greater stone size was 19 +/- 5 versus 19 +/- 4 mm. (p = 0.9), operative time was 159 +/- 61 versus 108 +/- 27 minutes (p = 0.01), stone-free rate at the end of ureteroscopy was 33 versus 87% (p = 0.001) and 3-month stone-free rate was 67 versus 100% (p = 0.02). Complications were not significantly different in either comparison. CONCLUSIONS: The overall likelihood that a patient would be rendered stone-free at ureteroscopy and 3 months after ureteroscopy favored holmium:YAG over electrohydraulic lithotripsy. For ureteral calculi less than 15 mm. electrohydraulic lithotripsy was more rapid than the holmium:YAG procedure but for ureteral calculi 15 mm. or greater the holmium:YAG technique was more rapid than electrohydraulic lithotripsy. The outcomes differences may have resulted from the different mechanisms of electrohydraulic and holmium:YAG lithotripsy.

Adult↗