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Biomedical subjects

D Righi

Publications and source records attributed to D Righi.

At least 19 recordsLinked to original sources
PubMed2004

Percutaneous radiological gastrostomy: a safe and effective method of nutritional tube placement in advanced ALS.

BACKGROUND: Enteral nutrition may be required in amyotrophic lateral sclerosis (ALS), and is usually achieved by percutaneous endoscopic gastrostomy (PEG). As PEG is not indicated in patients with severe respiratory impairment, an alternative is percutaneous radiological gastrostomy (PRG), involving air insufflation into the stomach under fluoroscopic guidance for tube insertion. OBJECTIVE: To evaluate the safety of PRG and its effect on survival and respiratory function in ALS patients with respiratory failure. METHODS: 25 consecutive ALS patients with severe dysphagia and forced vital capacity (FVC) <50% underwent PRG after October 2000. They were compared with 25 consecutive ALS patients with FVC <50% who underwent PEG before October 2000. Respiratory function was evaluated before and after the procedure. RESULTS: The two groups were similar for all relevant characteristics. PRG was successful in all cases, PEG in 23/25. One patient in each group died after the procedure. The mean survival time after the procedure was 204 days in the PRG group and 85 days in the PEG group (p<0.004). Respiratory function decreased more in the PEG group than in the PRG group (p<0.02). CONCLUSIONS: PRG appears to be safer than PEG in ALS patients with moderate or severe respiratory impairment, and is followed by a longer survival.

Aged↗
PubMed2002

Vascular reserve in the lower limbs of cirrhotic patients: a duplex Doppler ultrasound study.

AIM: To evaluate femoral artery impedance at rest and during reactive hyperaemia. PATIENTS: Study population comprised 11 cirrhotic patients without ascites, 10 with ascites and 16 age- and sex-matched healthy subjects. METHODS: Echocardiographic assessment of systemic haemodynamics; duplex Doppler ultrasound measurement of femoral artery pulsatility index and vascular reserve [pulsatility index rest/pulsatility index hyperaemia). RESULTS: Cirrhotic patients had elevated cardiac index and low systemic vascular resistance. Pulsatility index (right femoral artery) was not statistically different either at rest or after reactive hyperaemia (controls: rest 10.6 +/- 0.4, hyperaemia 2.6 +/- 0.2; compensated cirrhosis: rest 10.1 +/- 0.8, hyperaemia 3.4 +/- 0.4; ascitic cirrhosis: rest 11.4 +/- 1.6, hyperaemia 2.9 +/- 0.4. Vascular reserve was 4.38 +/- 0.35 in controls, 3.33 +/- 0.39 in compensated and 4.70 +/- 0.89 in ascitic cirrhosis (p = not significant). No correlation was found between systemic haemodynamic parameters and either pulsatility index or vascular reserve. CONCLUSIONS: The lower limb vascular reserve is preserved in cirrhosis.

Aged↗
PubMed2001

On the interaction between ultrasound and contrast agents during Doppler investigations.

Knowledge of interaction mechanisms between ultrasound (US) and contrast agents (CA) suspended in blood is important for a correct interpretation of clinical investigation results. Experiments performed in different laboratories have shown that, as a consequence of primary radiation force, CA tend to move away from the US transducer. Accordingly, Doppler spectra produced by particles suspended in moving water turn out to be significantly altered from what is theoretically expected. The purpose of this paper is twofold. First, an original model describing the bubble dynamics as the outcome of the balance between US radiation force and fluid drag force is validated for the case in which bubbles are suspended in blood. The high fluid viscosity is shown to prevent significant bubble deviations from the unperturbed fluid streamlines so that, in large vessels, a residual spectral distortion may exist only at the highest intensity levels permitted by current regulations. Finally, the relative importance and differences between the effect of primary radiation force and streaming mechanisms that, in principle, could lead to similar effects, are discussed.

Blood Pressure↗
PubMed2001

A simplified approach for real-time detection of arterial wall velocity and distension.

Arterial stiffness is known to increase with age and with many vascular diseases, but its noninvasive assessment in patients still represents a difficult task. The measurement of diameter change during the cardiac cycle (distension) has been proposed as a means to estimate arterial compliance and stiffness. Therefore, we have developed a simple PC-based device and algorithm for noninvasive quantification of vessel wall motion and diameter change in humans. This goal is achieved in real-time by processing the base-band signals from a commercial ultrasound Doppler system. Real-time operation is of crucial importance, because it allows a rapid achievement of optimal measurement conditions. The system was evaluated in a laboratory using a string phantom and was tested on the carotid arteries of 10 volunteers. Wall velocities from 0.05 to 600 mm/s and displacements lower than 2 microns were detected with phantoms. The measured carotid diameter change in the volunteers ranged from 7.5 to 11.8% (mean = 9.8%) and agrees closely with values reported in the literature. The difference between values taken one hour apart ranged from 0.2 to 0.5%. We conclude that the new system provides rapid, accurate, and repeatable measurements of vessel distension in humans.

Adult↗
PubMed1999

Is there any relationship between cold-induced vasodilatation and vasomotion?

There are many analogies between cold-induced vasodilatation (CIV) and vasomotion (VM), but the demonstration of any relationship between these two microvascular homeostatic reactions is to date lacking. In a group of seven controls and seven patients with Raynaud phenomenon in the vasomotor stage of the disease, we studied, by means of laser Doppler fluxmetry, the fingertip flow at room temperature (15 min), during hand immersion into cold water (0-6 degreesC, 30 min), and at room temperature again (15 min). The Fourier spectral analysis of the laser Doppler signal revealed in both groups two different patterns of the fingertip flow oscillations: the first was characterized by continued oscillations with small amplitude and median frequency of 2-8 cycles/min occurring both at room temperature and during cold stimulation. The second was characterized by continued oscillations of high amplitude and median frequency of 1 cycle/4-6 min occurring during cold stimulation only. The first pattern of flow oscillations still occurred during the second. The high-frequency oscillations are similar to the waves of vasomotion and the low-frequency oscillations are similar to the waves of cold-induced vasodilatation. Because 90-98% of the fingertip flow passes through arteriolar-venular anastomosis (AVAs), our results suggest that the CIV flow oscillations may be an expression of the AVA's VM.

Adult↗
PubMed1999

Duplex scanning exploration of the ophthalmic artery for the detection of the hemodynamically significant ICA stenosis.

BACKGROUND AND PURPOSE: The North American and the European Carotid Endarterectomy Trials demonstrated a significant benefit of surgery in preventing stroke for patients with symptomatic hemodynamically significant internal carotid artery (ICA) stenosis. Because the 3 angiographic methods of measuring carotid stenosis provide discrepant results, the indication for surgery depends on the method used for the evaluation of the angiogram. The goal of this study was to verify whether color duplex scanning of the ophthalmic artery alone might be reliable for detection of the extracranial hemodynamically significant ICA stenosis. METHODS: Three groups of patients (351 total patients) with transient ischemic attack or minor stroke referred for possible carotid endarterectomy were examined by means of color duplex scanning of the ICA, transcranial Doppler, color duplex scanning of the ophthalmic artery, and angiography of the ICA. RESULTS: In the first group (n=31) the comparison of findings from each method and the direct measurement of the residual lumen of plaque removed "en bloc" showed that the findings of the ophthalmic artery color duplex scanning, subdivided into 5 categories--NP (normal positive), LP (low positive), NF (no flow), REV (reverse flow), PP (pathological positive)--were associated with the best overall agreement (96.7%). The accuracy of the various categories of the ophthalmic artery color duplex scanning signals was studied in the second group of patients (n=200). The results pointed out that all but low positive categories were associated with high diagnostic accuracy. Finally, the results obtained in the third group (n=120) showed that a significant increase in the specificity of the low positive signal could be obtained by processing this signal in terms of pulsatility index and of transmission of pulsatility index. CONCLUSIONS: Our results suggest that the diagnostic capacity of color duplex scanning for the detection of ICA critical stenosis can be appropriately increased if it is performed also at the level of the ophthalmic artery and if the Doppler signals are processed on the basis of criteria we applied.

Aged↗
PubMed1997

An FFT-based flow profiler for high-resolution in vivo investigations.

Pulsed Doppler spectral analysis is a well-established diagnostic technique in the assessment of arterial diseases. Because of hardware limitations, its use has been so far restricted to the analysis of a single sample volume located along the ultrasound beam axis. In this paper, we discuss the operation of a newly developed multigate instrument capable of performing, in real time, 64-point fast Fourier transforms of Doppler signals sampled from 64 different range cells. The new instrument is capable of accurately detecting the actual blood flow behavior in major human vessels. Significant examples of velocity profiles obtained in real time from carotid arteries in healthy subjects are reproduced here for the first time. Multigate extension of spectral analysis is demonstrated to be a suitable means for detailed in vivo investigation of blood flow dynamics.

Blood Flow Velocity↗
PubMed1994

[Percutaneous gastrostomy. Personal experience in 137 cases].

Percutaneous gastrostomy is reported to be an effective alternative to total parenteral feeding or long-term nasogastric tube in the treatment of mechanical or functional dysphagia. The authors report their personal experience with 137 percutaneous gastrostomies performed on 98 men and 39 women from January 1986 through December 1993. All the maneuvers were performed under fluoroscopic guidance in the patients with head or neck cancer, neoplastic, vascular or post-traumatic neuropathy and upper GI tract cancer. To avoid left hepatic lobe trauma, percutaneous gastrostomy needs to be performed under US guidance. A 7F nasogastric tube is used to fill the stomach with air. After distending the gastric cavity, with the Seldinger technique under local anesthesia, fascial dilators of progressively increasing caliber are introduced into the gastric cavity and the final 12F gastrostomy catheter is positioned under fluoroscopic guidance. No major complications, such as hemorrhage or peritonitis, occurred. In one case, during the maneuver, the patient complained of severe epigastric pain which regressed with no further problems two hours later. In three cases the gastrostomy catheter fell out of place and was replaced by running the fistolous tract with a venous cannula and then a guidewire for gastrostomy repositioning. With this type of treatment, the patient can be given enteral feeding the following day. The maneuver requires approximately 10 minutes to perform and is well tolerated by the patient as it requires no general anesthesia. Percutaneous gastrostomy is more cost-effective than surgery or endoscopy and hospitalization is shorter. The only contraindications to this maneuver are hepatomegaly (because of the risk of liver trauma during percutaneous maneuvers), ascites (because of the risk of infection) and finally the complications resulting from gastric resection.

Adult↗
PubMed1992

Management of postoperative bile leakage with endoscopic sphincterotomy (EST) and a naso-biliary drain (NBD).

Between July 1987 and December 1990, 13 patients with postoperative bile leakage were treated with endoscopic sphincterotomy and a naso-biliary drain. All the leaks healed in two weeks, except for one (intrahepatic) that needed two months to heal in association with percutaneous management. The non-surgical treatment of bile leakage is the preferred approach on account of the superior safety, efficacy and cost-effectiveness as compared with surgical repair, which is associated with significant morbidity, mortality and costs. The treatment of choice has to be endoscopic, which is much easier and safer than the transhepatic approach, especially in the non-dilated duct, while another advantage over radiology includes the possibility for rapid definitive treatment of distal obstruction (e.g. residual stones). A leak from an extrahepatic duct heals rapidly, while a leak from an intrahepatic duct takes longer to heal and sometimes needs associated percutaneous drainage. Finally, the authors propose treating an extrahepatic bile leak merely with naso-biliary drainage without cutting the papilla, and an intrahepatic bile leak with endoscopic sphincterotomy, nasobiliary drainage and a bilio-duodenal endoprosthesis.

Bile Duct Diseases↗
PubMed1992

Fistulosphincterotomy in the endoscopic approach to biliary tract diseases.

We report our experience with 49 patients who underwent fistulosphincterotomy (FS) after cannulation of the common bile duct (CBD) by standard approaches had failed, due to suspected CBD obstruction. Only 4% of our cases turned out to have no biliary obstruction at all. The morbidity rate was 16%, and the mortality rate was 2%. In our series, FS raised the success rate of CBD cannulation from 90% to 96%. Ninety-five percent of successful cannulations were followed by endoscopic treatment. There were no cases of perforation or hemorrhage, and no difference in the success rate between FS in flat papillas and FS in bulging papillas, thanks, perhaps, to the technique we used. Our findings would indicate that FS is a useful procedure involving additional but not prohibitive risks. Nonetheless, it should be used only when CBD obstruction is strongly suspected and standard methods are not successful.

Adult↗
PubMed1992

[The percutaneous treatment of the urological complications following kidney transplantation].

Renal transplantation is considered the treatment of choice in most cases of renal failure; the urologic complication rate ranges 1 to 10% in different surveys. This work was aimed at evaluating the application and results of interventional radiology in these cases. Since 1983, 24 patients (20 males and 4 females) whose age ranged from 18 to 63 years (mean age: 42 years) have been submitted to percutaneous maneuvers in our department. Thirty-four complications were treated: 14 stenoses, 11 fistulas, 7 urinomas and 2 transient obstructions. Complete success was obtained in 15/24 patients (62.5%), while 7/24 patients (29.16%) underwent reoperation and in 2/24 cases (8.34%) a definitive pyelostomy catheter was inserted. In 7 stenosis cases ureteroplasty was successfully performed and a double-J endoprosthesis inserted; the follow-up results (5-21 months) were satisfying in all cases. The only complication was one case of endoperitoneal hematoma. Considering the good results obtained, the low morbidity and mortality and the low cost, percutaneous maneuvers must be considered the treatment of choice in the urologic complications of renal transplants. When the percutaneous treatment of the main lesion fails, pyelostomy does nonetheless allow the drainage of urinary collections, the maintenance of renal function and the improvement of local and general conditions, which makes it easier to reoperate under elective conditions.

Adolescent↗
PubMed1992

[Tubal catheterization with selective salpingography in the diagnosis and therapy of fallopian tube obstruction].

Fallopian tube catheterization with selective ostial [correction of osteal] salpingography is a new technique for the diagnosis of tubal factors of infertility and also for the treatment of proximal tubal occlusion (PTO). In this study, 246 women were considered, 20-42 years old, with primary or secondary infertility, who presented a unilateral or bilateral PTO at hysterosalpingography (HSG). Catheterization and selective salpingography have been successful in 93.9% of the cases. Failures (5.6%) have been ascribed to obstructive organic diseases, where it was impossible to overcome the stenosis with the catheter or the guide-wire. Twenty-six spontaneous pregnancies were obtained (15 full-term deliveries) and 17 patients became pregnant after GIFT (13 full-term deliveries). At follow-up, after 12 months 4 of 10 patients had normal tubes, while 6 patients presented a new unilateral or bilateral PTO. No major complications occurred; nevertheless, ectopic pregnancy is a possible event, because of the mechanically re-established patency in a nonfunctioning tube.

Adult↗
PubMed1992

[Percutaneous treatment of bile duct lithiasis. Personal experience in the first 150 cases].

Since 1983 we have percutaneously treated 150 cases of bile duct lithiasis in which previous endoscopic maneuvers had been incomplete or unfeasible. Complete resolution of lithiasis was obtained in 139 of 150 patients. In 6 cases only partial success was obtained but symptoms subsided. In 2 cases the treatment failed and the patients underwent surgery. Minor complications were observed in 12.6% of patients and resolved either spontaneously or by percutaneous maneuvers. Mortality rate was 2%. After a follow-up period of 6-12 months, 9 patients had a recurrence, completely resolved with further percutaneous treatment. These cases never required surgery. We obtained the best results in patients with stones residual after cholecystectomy or a iatrogenic stricture of the biliary tree. We obtained good results in massive lithiasis with combined endoscopic, surgical and radiological procedures. Morbidity and mortality rates were lower than in surgical series and similar to the endoscopic ones. The short hospitalization, the low cost and the possibility of treatment on an outpatient basis should promote the spreading of percutaneous techniques in the treatment of bile duct lithiasis.

Adolescent↗