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Biomedical subjects

M Grasso

Publications and source records attributed to M Grasso.

At least 127 records · Page 7Linked to original sources
PubMed1995

Intraluminal ultrasound-guided biopsy of the prostate: case report.

Patients who have undergone proctectomy can present a difficult diagnostic challenge for the urologist, as digital rectal examination and transrectal ultrasound scanning are not possible. Various methods have been tried to biopsy the prostate in patients without rectums and have proved to be limited in their usefulness. Intraluminal ultrasound employs a small high-frequency probe that creates an image from an intraluminal perspective. We describe a new role for this imaging method in which intraurethral intraluminal ultrasound scans can be used to guide perineal prostate biopsies in the patient without a rectum.

Aged↗
PubMed1995

Mechanical impactor employing Nitinol probes to fragment human calculi: fragmentation efficiency with flexible endoscope deflection.

The Browne Pneumatic Impactor (BPI; Browne Medical Systems, Minneapolis, MN) is a new mechanical lithotripter that relies on a pneumatically driven metal probe. It can be employed through both rigid and actively deflectable flexible endoscopes. Prior in vivo studies have shown excellent fragmentation of hard human calculi while employing the BPI with active endoscope deflection of as much as 45 degrees. In this study, we set out to define the efficiency of stone fragmentation with active endoscope deflection and to quantify the extent of retrograde stone migration that is often noted when mechanical lithotripters are employed. Pressure transducer testing of the BPI revealed an inverse relation between increased deflection of the endoscope and transduced voltage. Calculus fragmentation tests showed that as the endoscope was actively deflected to 90 degrees, the BPI still was able to fragment human calcium oxalate monohydrate calculi into extractable fragments with as few as six pulses. The maximum active endoscope deflection was 95 degrees with the 0.020-inch Nitinol probe passed through the working channel. At this deflection, the BPI was able to fragment an 8 mm pure calcium oxalate monohydrate calculus into two fragments after 14 pulses. Retrograde migration was evaluated by employing the BPI in a simulated ureter in a waterbath. The travel distance of a 5-mm 5-g calculus with one pulse averaged 12.2 mm (range 1-44 mm). Smaller, less dense calculi travelled farther. A rebound effect was occasionally noted, and this was associated with an off-center delivery. In conclusion, the BPI is an efficient mechanical lithotrite able to fragment hard human calculi when employed with active endoscope deflection of as much as 95 degrees. Delivered energy decreased with active endoscope deflection, but this change did not prevent fragmentation. Retrograde migration was an important variable more notable with smaller calculi.

Alloys↗
PubMed1995

Endopyelotomy: importance of crossing vessels demonstrated by endoluminal ultrasonography.

Endoscopic incision has become a common treatment for ureteropelvic junction (UPJ) obstruction. Recent reports have indicated the importance of crossing vessels in the success of endopyelotomy. Endoluminal ultrasound can define the location and size of adjacent vessels, and the effect of these vessels and their location on the success of endopyelotomy can be determined. A group of 28 patients found to have UPJ obstruction on excretory urography, retrograde ureteropyelography, radiographic nuclear scan, and clinical presentation were evaluated by endoluminal ultrasound at the time of endopyelotomy, which was performed by percutaneous nephroscopy or retrograde ureteroscopy. All patients had an indwelling ureteral stent postoperatively. Follow-up evaluation included renal ultrasound and nuclear scans. Excretory urography was performed in several patients. In this preliminary study, the success rate was lower in patients with vessels in a lateral position at the UPJ. The endoscopic approach did not alter the success rate. These factors should be considered in treating primary UPJ obstruction with endoluminal incision.

Adolescent↗
PubMed1995

Angiotensin converting enzyme gene deletion allele is independently and strongly associated with coronary atherosclerosis and myocardial infarction.

OBJECTIVE: To investigate the association of the three angiotensin converting enzyme (ACE) genotypes, DD, ID, and II, with the occurrence or absence of coronary atherosclerosis and with myocardial infarction and hypertension. DESIGN: Cohort analysis study. SETTING: North-Italy reference centre. SUBJECTS: 388 white Italian patients (281 males; mean age 60.7 (SD 12.5) years) with proven coronary atherosclerosis (n = 255) or with angiographically normal coronary arteries (n = 133). A further group of 290 healthy blood donors was tested for allele frequency comparison. INTERVENTIONS: ACE/ID polymorphism was analysed with polymerase chain reaction on DNA from white blood cells. MAIN OUTCOME MEASURES: Coronary atherosclerosis, myocardial infarction, hypertension. RESULTS: The D and I allele frequencies were respectively 0.63 and 0.37 in the overall healthy blood donor group and 0.66 and 0.34 in the overall study group. In the latter, univariate analysis showed (1) that coronary atherosclerosis (255 patients) was associated with the deletion allele, with an odds ratio (OR) of 5.78 for DD/II, P < 0.001, and 2.39 for ID/II, P = 0.006; and (2) that myocardial infarction (154 patients) was associated with the DD genotype (OR DD/II = 2.56, P = 0.007), but not with the ID genotype (OR DD/II = 1.96, P = 0.056). Finally, hypertension proved to be unrelated with the ACE genotype. The distribution between the three genotypes of known risk factors for coronary artery disease was similar. Logistic regression modelling, performed to test the association of the selected risk factors simultaneously with coronary atherosclerosis and myocardial infarction, showed that the deletion allele (whether DD or ID) was the strongest risk factor for atherosclerosis, and that the D allele was significantly associated with the risk of infarction (although to a lesser extent than with coronary atherosclerosis). CONCLUSION: ACE deletion polymorphism is strongly and independently associated with coronary atherosclerosis and, to a lesser extent, with myocardial infarction. As such, the results are analogous to what has already been reported in French white, Japanese, and Welsh coronary patients.

Adolescent↗
PubMed1995

Failures and complications of transurethral ureteroscopy in 297 cases: conventional rigid instruments vs. small caliber semirigid ureteroscopes.

To evaluate the safety and effectiveness of ureteroscopic stone manipulation, we retrospectively reviewed the failure and complication rates of two series of retrograde ureteroscopies (URS) according to the instrument used: the conventional rigid ureteroscopes and the new fiberoptic small size ureteroscopes. From July 1985 to December 1992, we performed 248 URS in 238 patients using a conventional rigid ureteroscope. From January 1992 to December 1992, we performed 49 URS in 47 patients using a semirigid ureteroscope. The failure rate was 14.5% in the first group of patients. The early and late complications observed were: urinary tract infections (UTI) in 22.5%, small mucosal lesions (false route) in 24.5%, full-thickness perforations in 11.2%, migration of the stone fragments into the retroperitoneum in 0.4% and the rupture of the tip of an alligator forceps into the ureteral lumen in 0.4%. Ureteral stenosis was observed in 1.6% of the cases. Often two or more complications occurred in the same patient. In the second group the failure rate was 10.2% and the complication rate 8.1%. We reported one case of ureteral perforation (2%), 3 mucosal lesions (6.1%) and UTI in 2 cases (4%). We conclude that URS using a small-caliber semirigid ureteroscope is a safer procedure than URS with conventional instruments. The majority of failures with semirigid scopes is related to the laser ineffectiveness in fragmenting the stone.

Adolescent↗
PubMed1995

Ureteral lithiasis: in situ piezoelectric versus in situ spark gap lithotripsy. A randomized study.

OBJECTIVES: In situ extracorporeal lithotripsy (EL) is the treatment of choice for ureteral lithiasis at our institution since the introduction of the painless lithotripters in clinical practice. The major objections to such clinical approach are: difficult ultrasound localization of ureteral calculi (if an ultrasound-guided lithotripter is used); lower energy of the painless piezoelectric compared to the spark gap system. To evaluate the efficacy of in situ EL of ureteral stones and to compare two different lithotripters (the spark gap fluoroscopically-guided Dornier HM3 versus the piezoelectric ultrasound-guided Wolf Piezolith 2300), we conducted a prospective randomized study. METHODS: 70 patients were randomly divided into two groups according to the following inclusion criteria: radiopaque stones of lumbar or prevesical tract (iliac and pelvic stones were excluded); stones with largest diameter not more than 2 cm. RESULTS AND CONCLUSION: The evaluation of the treatment was done by plain film (KUB) at 24 and 72 hrs and by ultrasound at 48 hrs to assess stone fragmentation using migration of the fragments more distally into the ureter as criteria for success. The results were comparable: 76.6% for extracorporeal piezoelectric lithotripsy (EPL) and 74% for extracorporeal shock wave lithotripsy (ESWL). Better results were observed in both groups for the prevesical stones. The focussing time required was also comparable.

Electricity↗
PubMed1995

Endoscopic management of the symptomatic caliceal diverticular calculus.

Caliceal diverticular calculi are most often asymptomatic and of little clinical significance. In certain cases they may be associated with flank pain, pyuria and chronic urinary tract infections. Treatment has evolved from open surgical techniques to a purely endoscopic approach. Percutaneous techniques are frequently used to address the diverticular stone burden and to dilate the diverticular neck, improving drainage. Small volume caliceal diverticular calculi and those in the anterior portion of the collecting system represent a greater technical challenge to the endoscopist. We describe a purely retrograde endoscopic technique for treating small stone burdens trapped in caliceal diverticula. Flexible ureteroscopy combined with 3F dilating balloons passed through the endoscopic working channel facilitated treatment. This retrograde technique was combined with a simultaneous primary percutaneous puncture into the diverticulum to treat larger stone burdens and calculi within long-necked diverticula. This combination facilitated prompt, through and through access of a percutaneously placed guide wire, increasing the overall efficiency of treatment. In conclusion, a retrograde endoscopic technique using the actively deflectable, flexible ureteroscope can successfully treat certain caliceal diverticular calculi. By combining this technique with a simultaneous percutaneous puncture, caliceal diverticular calculi throughout the collecting system may be cleared expeditiously.

Diverticulum↗
PubMed1995

Flexible ureteroscopically assisted percutaneous renal access.

OBJECTIVE: To combine retrograde flexible ureteroscopic techniques with a simultaneous percutaneous puncture to gain precise antegrade renal access in selected patients. METHODS: Patients with minimally dilated collecting systems and complex stone burdens (including caliceal diverticular calculi) underwent adjunctive flexible ureteroscopy in an attempt to expedite percutaneous renal access. This combined retrograde and antegrade approach was also used in treating obese patients and those in whom prior attempts at percutaneous renal access had failed. The prone split-leg position and flexible retrograde ureteroscopy were employed. The exact calyx for percutaneous puncture was selected under direct vision using an actively deflectable, flexible ureteroscope. Access to narrow infundibula and caliceal diverticula was facilitated by employing injectable guidewires as well as small-diameter balloon dilators passed through the working channel of the flexible endoscope. A fluroscopically guided percutaneous puncture was then performed. The tip of the intrusive needle was visualized both fluoroscopically and endoscopically. An antegrade guidewire was advanced through a ureteroscopically positioned snare and withdrawn out the urethra. With this through-and-through guidewire access, standard percutaneous tract dilation and nephroscopic lithotripsy were performed expeditiously. RESULTS: Seven patients with renal disease or body habitus that made precise percutaneous access difficult underwent adjunctive retrograde flexible ureteroscopy. One patient had a large perinephric hematoma from previous attempts at nephrostomy placement. The other six patients presented with: tightly branched staghorn calculi (three patients) and lateral/anterior caliceal diverticular calculi (three patients). Four patients were morbidly obese (240-320 lb), which also complicated antegrade access. Percutaneous renal access was obtained in < 30 min in all cases. CONCLUSION: A precise percutaneous puncture into a complex collecting system and establishing a through-and-through safety guidewire can be facilitated with simultaneous retrograde flexible ureteroscopic techniques.

Catheterization↗
PubMed1994

A 7.5/8.2 F actively deflectable, flexible ureteroscope: a new device for both diagnostic and therapeutic upper urinary tract endoscopy.

OBJECTIVE: To develop and employ in a prospective fashion a small-diameter, actively deflectable, flexible ureteroscope that could be easily placed into the upper urinary tract and would increase the overall therapeutic potential for this class of endoscope. METHODS: A small-diameter, actively deflectable flexible ureteroscope was recently employed in clinical trials at two university centers. Improvements in fiberoptic engineering allowed endoscope miniaturization (7.5 F tip and 8.2 F shaft) while maintaining a relatively large (3.6 F) centrally located working channel. A variety of design modifications were employed through various prototype stages. Mechanical parameters included maximizing two-way active deflection, adequate secondary deflection allowing access to the lower pole caliceal system, and maintaining a sturdy (nonbuckling) durometer. RESULTS: The 7.5 F flexible ureteroscope was employed in sixty-seven procedures (64 patients). Therapeutic rather than purely diagnostic maneuvers made up the majority of procedures. Thirty-one upper ureteral, renal pelvic, or caliceal calculi were treated with a variety of endoscopic lithotriptors placed through the ureteroscope. Six patients underwent both biopsy and endoscopic treatment of superficial papillary transitional cell malignancies. Retrograde endopyelotomy, incision or dilation of ureteral strictures, extraction of renal pelvic foreign bodies, and endoscopic access and treatment of obstructed caliceal diverticula were other applications. Endoscopic access to the upper urinary tract rarely required active intramural ureteral dilation (14%). Excluding patients with prior ureteral stents or those who underwent rigid distal third ureteral endoscopy prior to flexible proximal ureteroscopy, 31 patients (48%) required no intramural ureteral dilation prior to placing the endoscope. CONCLUSIONS: The increased therapeutic potential observed with the 7.5 F actively deflectable, flexible ureteroscope opens a variety of upper urinary tract pathologic states to minimally invasive (endoscopic) treatments.

Adolescent↗
PubMed1994

The limits of equilibrium in young and elderly normal subjects and in parkinsonians.

Body sway was studied at various body inclinations, voluntarily maintained for about 1 min, in young and elderly normals and in idiopathic parkinsonians. They stood on a dynamometric platform, whose output gave the instantaneous centre of foot pressure (CFP), its mean value and body sway area, with eyes open (EO) or closed (EC). Subjects held the normal upright stance, or the maximum possible inclined posture (body straight, rotated at the ankle joints) in forward or backward direction, or intermediate postures. EMG was recorded from tibialis anterior (TA), soleus (Sol), extensor digitorum brevis (EDB) and flexor digitorum brevis (FDB). The cross-correlation function between the profile of the EMG envelope and the profile of the shift of CFP along the sagittal plane was calculated. In young subjects standing with EO, the maximum extent of antero-posterior (A-P) displacement of CFP was about 60% of foot length. EC reduced this value to about 50%. In the elderly normals, the maximum A-P displacement was about 40% (EO) and 30% (EC). In both groups, sway area was minimal during normal stance with EO and increased progressively when the subjects leant forward or backward. With EC, sway area further increased during normal stance and the rate of increase in relation to inclination augmented markedly. Sol was tonically active during normal stance. Forward leaning increased Sol EMG and induced activity in FDB. TA and EDB were active during backward leaning. The peak of the cross-correlation function between Sol EMG and instantaneous CFP was higher during normal stance than forward inclination, while the reverse was true for FDB. This suggests a role of FDB in the fine-tuning of postural adjustment during forward leaning, and a weight-supporting role of Sol. During backward inclination, TA but not EDB was cross-correlated with CFP. In the parkinsonians, maximum A-P displacement of CFP was just about 30% of foot length (EO; about 20% with EC); its extent was inversely correlated with the severity of the disease. The relationship between sway area and A-P displacement was similar to the elderly, both with EO and EC, within the common range of inclination. In the patients affected by the long-term syndrome, A-P displacement was further reduced while sway area increase at the critical postures was often absent. In all patients, the relationship between muscle activity and body inclination was comparable to normal.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1994

Inability to pass a urethral catheter: the bedside role of the flexible cystoscope.

An all too common cause of urologic consultation is the inability to place a urethral catheter. Often other health care providers have unsuccessfully attempted catheter placement. Urethral false passages, perforations, and edema are common sequelae. Diseases such as urethral strictures, bladder neck contractures, and prostate cancer are often the underlying etiologies for failed catheterization. Traditionally, the use of filiforms and followers or the placement of a suprapubic tube is required to drain the lower urinary tract. Bedside flexible endoscopy was performed in this series not only to define the area and etiology of urethral obstruction, but also to facilitate catheter placement. Fifty-four patients were studied prospectively. Initial endoscopic assessment was based on bedside flexible cystoscopy. Most procedures were performed under topical lidocaine anesthetic. Under direct vision a 0.038 inch standard guide wire was directed through the area or areas of obstruction. Strictures, fibrosis, and false passages were dilated using a series of graduated Nottingham dilators over the guide wire. A Council-tipped urethral catheter was then placed over the guide wire to assure bladder drainage. In 52 of the 54 patients urethral obstructions were dilated and drainage catheters were placed into the bladder. No complications were encountered. This technique is simple, it avoids suprapubic puncture, and it minimizes unneeded trips to the operating room.

Cystoscopes↗
PubMed1994

Treatment of urinary calculi in a porcine and canine model using the Browne Pneumatic Impactor.

OBJECTIVES: To define the safety and efficacy of a pneumatically driven, mechanical lithotriptor using nitinol probes through semirigid and actively deflectable, flexible fiberoptic endoscopes. METHODS: The Browne Pneumatic Impactor (BPI) uses standard compressed air to drive a nitinol wire along its long axis onto a calculus, fragmenting it. Bench top and in vivo experiments were designed to explore variables, including the effects of various nitinol probe tip designs, outer diameters, excursion distances, and sheathing materials as well as the efficiency of fragmentation with active endoscope deflection. In vivo experiments in two animal models (porcine and canine) were performed using small diameter, fiberoptic semirigid, and actively deflectable, flexible ureteroscopes. Surgically placed calculi were fragmented with the BPI and representative tissue was obtained immediately and up to 2 weeks postoperatively to define histologic changes. A panel of human urinary calculi was chosen for their relative difficulty in fragmentation with other modalities. RESULTS: Calculi, including pure calcium oxalate monohydrate, brushite, cystine, and triamterene, were fragmented with the BPI used through both semirigid and actively deflectable, flexible endoscopes. A rounded tip design and excursions of 1 mm fragmented calculi most efficiently with minimal histologic reaction. Retrograde stone migration before fragmentation was noted in dilated upper urinary tracts. This was prevented by first entrapping the calculus within a standard basket. Ureteral calculi were fragmented with the nitinol probes deflected up to 45 degrees by the flexible endoscope. With increased active deflection, the efficiency of fragmentation decreased. CONCLUSIONS: The BPI represents a safe, thermal-free endoscopic lithotrite able to fragment the hardest calculi through semirigid and flexible ureteroscopes.

Alloys↗
PubMed1994

Flexible cystoscopic bladder biopsies: a technique for outpatient evaluation of the lower urinary tract urothelium.

Routine urothelial biopsies of the lower urinary tract are obtained using the cold cup biopsy technique. This procedure is most often performed in the surgical suite and requires rigid endoscopic access and the use of biopsy forceps and Bugbee electrodes to obtain tissue for histologic examination. A new single-step biopsy forceps has been used through the flexible cystoscope. Using a 16 F actively deflectable, flexible cystoscope and the 5.4 F Therma Jaw Hot Urologic Forceps, bladder biopsies were obtained in 27 patients for a variety of indications. This biopsy forceps allows simultaneous tissue sampling and electrocoagulation of the biopsy site, thus eliminating the need for exchange of instruments through the flexible cystoscope. Tissue samples are somewhat protected from thermal changes during coagulation through the use of a Faraday cage. Biopsies were frequently obtained in an outpatient setting, requiring only local topical anesthesia (2% lidocaine jelly). Carcinoma in situ, transitional cell carcinoma, acute and chronic inflammation, and normal bladder mucosa were differentiated histologically. Using this technique, lower urinary tract urothelial mapping can be performed safely in the office with minimal patient discomfort.

Ambulatory Care↗
PubMed1994

Endoscopic pulsed-dye laser lithotripsy: 159 consecutive cases.

The application of the coumarin-based pulsed-dye laser has allowed the endoscopist to employ more delicate instruments with smaller working channels in treating urinary and biliary calculi. We have previously reported our first 100 patients treated with this laser. In 159 consecutive patients, 176 renal, ureteral, bladder, urethral, and biliary calculi with an average size of 1.6 cm were treated with the pulsed-dye laser in antegrade or retrograde fashion using rigid (6.9F-11.5F) or flexible (8.5-10.5F) endoscopes. The laser fibers ranged from 200 to 550 microns and the energy from 60 to 200 mJ. In some cases, the laser was used as an adjunct to percutaneous nephrolithotomy for staghorn calculi, to fragment bladder calculi without anesthesia, to free encrusted ureteral catheters, or as a lithotrite in the biliary tree. Only 4 stones (2.5%) could not be fragmented. There were no complications directly attributable to the use of laser energy. The pulsed-dye laser is safe and efficacious as an endoscopic lithotrite.

Anesthesia↗
PubMed1994

Endoluminal sonography in evaluation of the obstructed ureteropelvic junction.

Endoluminal sonography is a technique well suited to imaging structures beyond the lumen of the hollow viscus. The development of small-diameter (6.2F), catheter-enclosed ultrasound probes has made this technique available for use within the urinary tract. It is capable of defining adjacent vessels, calculi, and masses. Ureteropelvic junction (UPJ) obstruction has been increasingly treated by incisional techniques, either nephroscopic, ureteroscopic, or radiographically controlled, with each incision at risk for causing damage to any adjacent vessel. Endoluminal sonography of the obstructed UPJ was attempted in 46 patients and completed in 45 patients, 41 with primary and 4 with secondary obstruction. Adjacent vessels could be seen in 24 patients. Twelve were located anterior or medial to the UPJ or both. Nine patients had vessels at the UPJ located laterally or anterolaterally, posterolaterally, or medially and laterally. Sonographic localization guided the choice of incision site in all patients and changed therapy in five patients. This technique also allows recognition of high insertion of the ureter into the renal pelvis. Endoluminal sonography of the obstructed UPJ is a valuable technique to determine the location and nature of associated vessels and, therefore, to guide decisions in treatment.

Adult↗
PubMed1994

[Diagnostic and research potential of directional atherectomy].

Directional coronary atherectomy (DCA) is the sole technique for the in vivo study of coronary artery plaques which are responsible for myocardial ischemia. The technique confers the following advantages to the pathologic study of plaque samples: the brevity, in general, of the interval between acute myocardial ischemia and sampling of the guilty plaque; the absence in samples of autolytic phenomena (such as those that affect autopsy samples), an effect that enables the use of conventional histopathology, immunohistochemistry and molecular biology; the certainty with which the researcher can identify, and thus sample, the truly guilty lesions. The drawbacks of the technique are: the fragmentation of the plaque; the difficulty the pathologist has in correctly orientating the samples in the embedding phase, in distinguishing pre- from post-procedural lesions, and in providing a detailed description of the findings. Given the foregoing, the diagnostic information to which DCA sampling enables access is as follows: plaque derivation--the recognition of whether tissue removed with DCA originates from eccentric or concentric, atheromatous of fibrosclerotic, calcified or not calcified plaques; histopathology of coronary lesions that cause ischemia with regard to: evidence of acute events, such as thrombosis, ulceration and hemorrhage, thrombus composition, when it occurs, and definition of its age and presence of material deriving from the vascular wall that lies beyond the plaque; identification and immunophenotypical characterization of inflammatory infiltrates. As regards research, the main implications of DCA are for the study of the pathogenetic mechanisms that lead to plaque instability in acute ischemic syndromes.(ABSTRACT TRUNCATED AT 250 WORDS)

Atherectomy, Coronary↗