Usefulness and limits of distal echo-Doppler velocimetric indices for assessing renal hemodynamics in stenotic and non-stenotic kidneys.

BACKGROUND: Distal echo-Doppler velocimetric indices are widely used for revealing the presence of a renal artery stenosis but there is scarce information as to whether they reflect the renal hemodynamics in stenotic and nonstenotic kidneys. OBJECTIVES AND METHODS: We evaluated the pulsatility and resistive indices (PI and RI), acceleration (A) and acceleration time (At) and correlated their values with those of effective renal plasma flow (ERPF), glomerular filtration rate (GFR), renal vascular resistance (RVR) and filtration fraction (FF) estimated by single kidney scintigraphy in 24 kidneys with 70-95% renal artery stenosis (atherosclerotic n = 17, fibromuscular n = 7) and in 27 non-stenotic kidneys (11 contralateral to renal artery stenosis and 16 of patients with essential hypertension). In patients with stenotic kidneys, these measurements were repeated within 7 days after a successful percutaneous transluminal renal angioplasty (PTRA) (in 11 arteries performed in combination with stent implantation). RESULTS: Prior to dilation we found that the stenotic kidneys had significantly lower values of ERPF, GFR and higher RVR than the non-stenotic kidneys and that these hemodynamic alterations were associated with those, also statistically significant, of the four velocimetric indices. In non-stenotic kidneys, there were highly significant relationships between PI and ERPF, and RVR (r = -0.68 and 0.81 respectively P < 0.01); similar relationships were found for RI (r = -0.67 and 0.78 P < 0.01) whereas no such correlations were found between these two velocimetric indices and GFR and FF; also no correlations were found between A and Atand ERPF, GFR, RVR and FF. In stenotic kidneys no significant correlations were found between any of the velocimetric and the hemodynamic indices. Renal artery dilation induced clear cut increments in ERPF, GFR and reduction in RVR in post-stenotic kidneys, which were associated with normalization of all four velocimetric indices. No relationships were observed between the renal hemodynamic and the velocimetric changes induced by dilation; however in post-stenotic kidneys the relationships between PI and RI, ERPF and RVR were restored as in nonstenotic kidneys. CONCLUSIONS: These data indicate that PI and RI can be used to assess ERPF and RVR both in non-stenotic and post-stenotic kidneys; however, none of the velocimetric indices examined in this study can provide valid informations on the renal hemodynamics of stenotic kidneys and on their changes induced by PTRA.

Angioplasty of atherosclerotic and fibromuscular renal artery stenosis: time course and predicting factors of the effects on renal function.

The effects of percutaneous transluminal renal angioplasty (PTRA) on the renal function of stenotic kidneys are usually assessed by evaluating the changes in serum creatinine, which is quite a rough indicator of glomerular filtration rate (GFR). In 27 hypertensive patients with 19 atherosclerotic and 11 fibromuscular significant renal artery stenoses, we investigated with renal scintigraphy the short-term (5 days) and long-term (10 months) effects of a technically successful PTRA (in seven cases combined with a stent implantation) on GFR of the stenotic and contralateral kidneys; these measurements were combined with those of plasma renin activity (PRA) and of angiotensin II (AII). We found that in short-term studies after PTRA GFR rose from 29.7 +/- 3.5 to 34.6 +/- 3.1 mL/min and from 36.9 +/- 4.0 to 45.1 +/- 4.3 mL/min, respectively, in atherosclerotic and fibromuscular poststenotic kidneys. In long-term studies GFR further and significantly increased, to 37.8 +/- 3.2 mL/min in the former group, whereas it stabilized in the latter group (46.0 +/- 3.6 mL/min). In patients with fibromuscular stenosis these changes in GFR were associated with clear-cut reductions in blood pressure (BP), PRA, and AII; these decrements also occurred in patients with atherosclerotic stenosis but to a much lesser extent. We also found that in short- and long-term studies the percent of PTRA-induced increments of GFR in the poststenotic kidneys were inversely correlated with the baseline values of GFR. In addition, the absolute and percent increments of GFR were positively correlated with the basal levels of AII. Thus the time course of the improvement in GFR after angioplasty may differ in kidneys, depending on the etiology of the stenosis, in that in those with fibromuscular stenosis it was entirely apparent within a few days whereas in those with atherosclerotic stenosis it required several months to be fully expressed. Also, it appears that the more compromised kidneys are those that benefit most from the dilatation and that AII levels are useful indicators of the possibility that the stenotic kidney will have a favorable functional outcome in terms of restoration of renal blood flow.

Renovascular disease and hypertension in children with neurofibromatosis.

Neurofibromatosis type 1 (NF1) is associated with vascular lesions, such as renal artery stenosis, and secondary hypertension. The real prevalence is largely unknown, particularly in children. We observed 27 patients with NF1, mean age 12.8 years (range 4.2-24 years), for 2-10 years to assess the association of NF1 with vascular abnormalities and secondary hypertension. Patients were studied with angiography, 24-h blood pressure monitoring, a captopril test, and Doppler ultrasonography of aorta and renal arteries. The prevalence of hypertension was 18.5%; 61.5% of patients studied with angiography had vascular lesions, half of whom were apparently normotensive. However, they had abnormal 24-h blood pressure monitoring, which was a first sign of poor blood pressure control. Those patients with severe hypertension (11.1%) were successfully treated with percutaneous transluminal angioplasty (PTA); stenosis recurred in 2 of 3 patients after a 2-year follow-up period, and was responsive to drugs. We conclude that hypertension is a frequent complication of NF1 in pediatric patients, it is usually secondary to typical vascular lesions, and requires careful follow-up. Ambulatory blood pressure monitoring (24-h) is a sensitive method for detecting initial alterations of the blood pressure pattern. PTA may be an effective treatment in this condition.

Variability of renal echo-Doppler measurements in healthy adults.

BACKGROUND: We examined the most widely used echo-Doppler variables in healthy adults to define their normal distribution and variability in relation to age, sex, body surface area and the right and left kidney. METHODS: Ninety healthy subjects were selected, stratified for sex and age (range 20-65 years). We also examined 8 subjects with a congenital solitary kidney and 15 surgically nephrectomized patients. Variables studied were the diameters and volume of the kidneys, renal blood flow (RBF) and resistive index (RI) measured on the renal, interlobar and cortical arteries. RESULTS: The mean length was greater in the left kidney (p<0.01) and width in the right one (p<0.02). Volume was no different on the two sides. RBF showed an age-dependent reduction (p<0.0001), while interlobar (p<0.0001) and cortical (p<0.0001) RI showed a selective age-dependent increase. RI were higher in females and diameters, volume and RBF, after correction for body surface area, were not different in the two sexes. Cortical RI was lower than the interlobar and renal RI (p<0.0001). In the group with congenital single kidney, length, volume and RBF were all greater. In the mononephrectomized patients, length and volume were greater but RBF was the same as in a normal single kidney. CONCLUSIONS: The ultrasonographic and Doppler variables studied did not show any differences from normal distribution but they were influenced differently by some demographic parameters; however, the integrated use of these measurements offers precision and repeatibility, and could help evaluating diffuse or localized abnormalities.

[Carbon dioxide angiography. A new injection system]. / Angiografia con anidride carbonica. Nuovo sistema di iniezione.

PURPOSE: To evaluate the usefulness of a new carbon dioxide (CO2) intravascular injection system in digital subtraction angiography. MATERIAL AND METHODS: March 1998 to May 1999, thirty-nine patients were submitted to digital subtraction angiography with CO2 injection by a new delivery system, CO2-Angioset, OptiMed, Ettingen, Germany. The patients were 29 men and 10 women, whose age ranged 32 to 76 (mean: 47), eighteen of them with absolute or relative contraindications to iodinated contrast media and 6 with poor diagnostic findings at previous conventional angiography. CO2 was used for comparison with iodinated contrast agents in 4 patients. We studied the following vascular districts: renal arteries in 9 patients, portal vein in 18, lower limb arteries in 7, upper limb veins in 4. In 1 patient CO2 angiography was carried out for the diagnosis and interventional treatment, by transcatheter embolization, of a postbioptic arteriovenous renal fistula. During the procedure, arterial blood pressure, EKG status and oxygen stauration were monitored, and subjective sensations recorded in all patients. RESULTS: CO2 angiography provided adequate visualization of vascular districts and of abnormal findings in 32 cases (82%), while its results were considered insufficient for correct and complete assessment in 7 cases (18%). In detail, renal arteries studies were adequate in 9/9 cases, providing good depiction of the arterial trunk and main branches but poor demonstration of interlobar and arcuate arteries. The portal trunk was well depicted in 12/18 cases, but CO2 angiography results were insufficient in 3 cases because of poor catheter wedging in the hepatic vein and in 2 cases because of CO2 drainage by an accessory hepatic vein. Peripheral circulation was clearly depicted in 5/7 cases, while there was incomplete filling of the abdominal aorta and of iliac and femoral arteries in 2 cases. We had only one transient complication (2.57%) due to mesenteric ischemia during an aortic injection, with mild abdominal pain and diarrhea which subsided spontaneously in few minutes. CONCLUSIONS: In our experience the CO2-Angioset delivery system has proved to be a simple and safe tool, particularly suitable for use in patients at risk for allergic reactions to iodinated contrast agents and in those with renal function impairment. Also, the system can help carry out some interventional procedures such as arteriovenous fistula embolization and transjugular portosystemic shunting.

Interventional radiology in the treatment of urological vascular complications.

Urological vascular complications (UVC) are largely secondary to percutaneous procedures that are nowadays extensevely used by the urologists and the nephrologists. The major frequency of UVC is observed after the renal biopsy, in a percentage varying from 7 to 17% in different series; UVC are less frequent after a nephrostomic procedure (near 1-3%). UVC consist of artero-venous fistulas (AVF) and pseudoaneurysms (PA), that generally cause haemorrhage, particularly macroscopic hematuria. In the vast majority of cases hematuria resolves spontaneously or with conservative therapy but, in the 4 to 9% of patients persists and requires an adequate therapy, often in emergency. Interventional radiology permits an effective and timely treatment of the lesions, using the techniques of transcatheter embolization that are greatly improved in the last 20 years and that present rate of technical success greater than 80%. Moreover radiological embolization shows a low incidence of complications and lower hospitalization cost with respect to surgical treatment. Herein we describe the different techniques of embolization, the indications and the results as appears from the literature and the personal experience. The latter is based on a series of 31 procedures performed in 26 patients, with a rate of technical and clinical success of 93.5%.

Interventional radiology in the treatment of renal artery stenosis.

Percutaneous transluminal renal angioplasty (PTRA) alone or in combination with stent implantation, is increasingly used as an alternative technique to surgical revascularization for treatment of renal artery stenosis (RAS) wich may cause hypertension or jeopardize renal function. Herein we report the results obtained with 305 PTRAs performed in 242 hypertensive patients, 144 of whom had atherosclerotic RAS, 69 fibromuscolar dysplasia, 15 Ras in transplanted kidneys, 6 restenosis in surgically revascularized kidneys, 4 Takayasu arteritis and 4 neurofibromatosis. Stents were implanted in 68 cases, mostly in atherosclerotic stenoses. The technical success was achieved in 261 arteries (85.6%), with 33 failures (10.8%) and 11 (3.6%) procedures not completed for anatomical reasons. PTRA related complications were observed in 23 cases (7.5%), but no fatalities occurred. An overall benefit on blood pressure control was observed in 41% of patients with atherosclerotic RAS and in 68% of those with fibromuscolar dysplasia. It appears that independently from the ethiology PTRA is technically effective in correcting RAS; yet the position of PTRA with respect to that of medical or surgical treatment needs to be better delineated through randomized, controlled studies aimed at comparing the clinical efficacies of these different approaches.

Arterial embolization in the treatment of post-traumatic priapism.

Priapism is a prolonged penile erection not associated with sexual arousal. Two types of priapism have been described: the more common one is the "veno-occlusive" priapism and can be frequently observed as the consequence of an intracavernosal injection of vaso-active drugs for the treatment of erectile dysfunction. The less common type of priapism is known as "high flow" priapism and usually follows perineal or direct penile trauma. The clinical presentation in case of high flow priapism is quite typical: hystory of recent penile or perineal trauma followed, by the onset of a painless, incomplete and constant erection of the penis. A color-flow Doppler sonogram should be performed as first diagnostic step: this examination allows to identify the presence of patent cavernous arteries and prominent venous drainage with focal area of high flow turbulence along the pathway of one or both the cavernous arteries. An arterial blood sample taken from the corpora will confirm the diagnosis. At first, conservative therapeutical attempts can be suggested, with mechanical external compression of the perineum, the use of ice packs, corporeal aspiration and irrigation with saline. Besides, intracorporeal administration of alpha-agonists and methylene blue should be performed. Unfortunately, these conservative measures often result unsuccessful, and more invasive approaches must be considered. The radiological superselective transcatheter embolization of the proximal artery supplying arterial-lacunar fistula should be the present treatment of choice in these cases of high-flow priapism refractory to conservative and medical treatments. The first successful management of high flow priapism by selective arterial embolization was reported by Wear and coworkers in 1977. Autologous clots and gelatine sponge have been extensively used and become very popular as the embolic agent. More recently, platinum microcoils have been proposed with the aim to achieve more precise and selective embolization. In our single-case-experience on the treatment of high flow priapism by arterial embolization, we used the recently introduced tungsten microcoils. At the time of the follow-up, 2 months later, patient reported satisfactory intercourse with an approximately 75% of penile rigidity. By comparison with microsurgical ligature of the damaged vessel, selective embolization is, at least theoretically, a less invasive procedure, particularly with reference to the trauma caused to the erectile tissue. High-flow priapism is a fairly rare urological pathology which does not require immediate and emergency treatment (as is the case, instead, with venous-occlusive priapism), since the risk of post-ischaemic fibrosis is excluded thanks to the fact that oxygen is supplied to the cavernous tissue. Once the diagnosis has been established with certainty, therefore, the specialist has the necessary time at disposal to arrange for the most appropriate therapeutic steps. When, as is frequently the case, conservative measures prove ineffective, the current treatment of choice for cases of fistula of the cavernous artery would appear to be superselective embolization of the artery, provided same can be performed at specialized centres and by experienced personnel.

[Bleeding in diverticular disease of the colon]. / Il sanguinamento nella malattia diverticolare del colon.

The incidence of bleeding from diverticular disease ranges from 3 to 30%. Haemorrhage is more common when the whole colon is affected; the source is more frequently in the right colon. Typically, the bleeding is massive, with 15% of the patients admitted in shock. It nearly always stops spontaneously, but recurrence rate is high. Chronic blood loss suggests alternative sources. Emergency angiography detects aetiology and site of the haemorrhage in most of the patients. Vasopressin infusion can frequently stop the bleeding. Colonoscopy is profitable only when bleeding stops, after a rapid clearing of the colon. On the other hand, intraoperative colonoscopy could be useful in emergency cases when urgent surgery is clearly indicated. Surgical treatment is requested only in few patients: segmental resections (generally right hemicolectomy) are indicated when there is evidence of the source of the blood loss. In the other cases sub-total or total colectomy are justified and provide better and safer results.

Effects of balloon angioplasty and stent implantation on intrarenal echo-Doppler velocimetric indices.

This study was aimed at examining whether four intrarenal echo-Doppler velocimetric indices (pulsatility and resistive indices, acceleration and acceleration time) can be useful for assessing the effects of renal artery dilation obtained with either angioplasty or stent implantation. Echo-Doppler studies were performed in 63 hypertensive patients with 68 renal artery stenoses (39 atherosclerotic and 29 fibromuscular) prior to and within five days after the dilation procedures (55 angioplasties, 13 stent implantations), which resulted in an average reduction of arterial narrowing from 79% to 20%. In 24 patients, the velocimetric indices were also examined in relationship to the venoarterial differences of plasma renin activity and of angiotensin II across the stenotic kidneys. We found that after dilation the values of the four indices had returned within the normal range in all but three arteries (one false negative for resistive index and two for acceleration time). However, decrements in acceleration time was the only factor to be significantly correlated with the reduction of arterial narrowing. Moreover, postdilation values of this index were, on average, slightly but significantly higher in arteries that at follow-up developed restenosis rather than in those that remained patent. For similar reductions in arterial narrowing the absolute changes of all indices were similar in atherosclerotic and fibromuscular stenotic arteries and, in a subset of the atheromatous arteries, were also similar after angioplasty and stent implantation. No relationship was found with the changes in the venoarterial differences of plasma renin activity and angiotensin II. It appears that these intrarenal velocimetric indices and, in particular, acceleration time reliably reflect the technical success of renal artery dilation. The acceleration time index may also be valuable for predicting the restenosis of the dilated vessel. None of the indices, however, mirrors the functional consequences of removal of renal artery stenosis as expressed through the changes in transrenal gradients of the components of the renin-angiotensin system.

Transjugular intrahepatic portosystemic shunt versus endoscopic sclerotherapy for the prevention of variceal bleeding in cirrhosis: a randomized multicenter trial. Gruppo Italiano Studio TIPS (G.I.S.T.).

Transjugular intrahepatic portosystemic shunt (TIPS), a new technique for the treatment of portal hypertension, has been successful in preliminary studies to treat acute variceal hemorrhage and to prevent variceal rebleeding. The purpose of this multicenter, randomized controlled trial is to compare the efficacy of TIPS with that of endoscopic sclerotherapy in the prevention of variceal rebleeding in cirrhosis. Eighty-one cirrhotic patients, with endoscopically proven variceal bleeding, were randomized to either TIPS (38 patients) or endoscopic sclerotherapy (43 patients). Randomization was stratified according to the following: if bleeding occurred < 1 week (stratum I); if bleeding occurred 1 to 6 weeks (stratum II); and if bleeding occurred 6 weeks to 6 months (stratum III) before enrollment. Follow-up included clinical, biochemical, Doppler Ultrasound, and endoscopic examinations every 6 months. During a mean follow-up of 17.7 months, 51% of the patients treated with sclerotherapy and 24% of those treated with TIPS rebled (P = .011). Mortality was 19% in sclerotherapy patients and 24% in TIPS patients (P = .50). Hepatic encephalopathy (HE) developed in 26% and 55%, respectively (P = .006). A separate analysis of the three strata showed that TIPS was significantly more effective than sclerotherapy (P = .026) in preventing rebleeding only in stratum I patients. TIPS is significantly better than sclerotherapy in preventing rebleeding only when it is performed shortly after a variceal bleed; however, TIPS does not improve survival and is associated with a significantly higher incidence of HE. The overall performance of TIPS does not seem to justify the adoption of this technique as a first-choice treatment to prevent rebleeding from esophageal varices in cirrhotic patients.

Percutaneous treatment of iliac aneurysms and pseudoaneurysms with Cragg Endopro System 1 stent-grafts.

PURPOSE: To evaluate the feasibility and short-term follow-up results of treating iliac aneurysms by the Cragg Endopro System 1 stent-graft. METHODS: Nine lesions (two pseudoaneurysms and seven atherosclerotic aneurysms) were treated in eight patients by percutaneous implantation of a total of 10 stent-grafts. The procedure was followed by anticoagulation with heparin for 6 days, then antiplatelet therapy. Follow-up was by color Doppler ultrasound scan at 2 days and 3 months after the procedure for all patients, and by venous digital subtraction angiography and/or angio-CT up to 12 months later for four patients. RESULTS: Initial clinical success rate was 100% and there were two minor complications. In one case the delivery system was faulty resulting in failure to deploy the stent-graft. An additional device had to be used. At 3-12 months all prostheses were patent but one patient (12.5%) had a minimal pergraft leak. CONCLUSION: Percutaneous stent-grafting with this device is a safe and efficacious treatment of iliac artery aneurysms.

Superiority of acceleration and acceleration time over pulsatility and resistance indices as screening tests for renal artery stenosis.

OBJECTIVE: To compare the accuracy of four echo-Doppler-derived velocimetric indices (pulsatility and resistance indices, acceleration and acceleration time) in detecting renal artery stenosis in hypertensive patients. PATIENTS AND METHODS: In 73 hospitalized patients with moderate-to-severe hypertension, 18 of whom had normal renal arteries and 55 renal artery stenosis (50-95%) either atherosclerotic (30 cases, five bilateral) or fibromuscular dysplasia (25 cases, two bilateral), we measured the four velocimetric indices using the lateral abdominal approach and sampling Doppler waveforms distally to the stenosis. The diagnostic accuracy of each index was calculated using as cut-off limit the ideal threshold determined with the receiver-operating characteristic curves. RESULTS: On average all of the indices were altered significantly in arteries with stenosis of both aetiologies with respect to normal arteries, the alterations of pulsatility and resistance indices being, however, less pronounced than those of acceleration and acceleration time, particularly in atherosclerotic stenosis. With the cut-off limits of 0.93, 0.59 and 7.4 m/s2 and 60 ms, respectively, for pulsatility and resistance indices, acceleration and acceleration time, their diagnostic accuracies were 80, 73, 93 and 92%. In stenotic arteries, only the acceleration time was correlated with the degree of arterial narrowing, whereas, in normal arteries, only pulsatility and resistance indices were directly correlated with the age of patients. CONCLUSIONS: Acceleration and acceleration time are more accurate indices than pulsatility and resistance to screen for renal artery stenosis, probably because their alterations are less attenuated by the counterbalancing effects of age and of atherosclerosis.

Prevention of variceal rebleeding and treatment of liver carcinoma by consecutive transjugular intrahepatic portosystemic shunt and hepatic artery chemoembolization.

Variceal bleeding and hepatocellular carcinoma are two severe complications of cirrhosis. One of our patients who bled from oesophageal varices was found to have a malignant hepatic nodule. As the patient refused liver transplantation, a transjugular intrahepatic portosystemic stent was carried out for portal hypertension, and transcatheter arterial chemoembolization for cancer. Both procedures were successful and one year later liver function has not deteriorated. This case shows that intrahepatic stent placement and selective arterial chemoembolization can be safely performed in cirrhotic patients with a solitary hepatocarcinoma nodule and a good liver function reserve.

[Percutaneous angioplasty (PTA) in the treatment of non-penetrating injuries to the subclavian artery. A clinical case]. / Trattamento con angioplastica percutanea (PTA) di lesione da trauma non penetrante dell'arteria succlavia. Caso clinico.

Non penetrating injuries to the subclavian vessels are uncommon. We present a case of a young patient with an isolated blunt trauma of the right subclavian artery. The patient, a 25 year-old woman, was admitted to our Institute after a motor-vehicle accident, with a physical findings of absent peripheral pulses and right clavicular fracture, confirmed by non-invasive vascular evaluation and X-ray of the chest. Diagnosis was established by an urgent selective angiography that showed a subintimal hematoma with occlusion of the vessel and peripheral ischemia of the arm. The patient clinical status (hemodynamically stable) permitted a conservative management and a transluminal percutaneous angioplasty (PTA) with a trans-femoral catheter balloon. After radiologic treatment, the patient showed good palpable peripheral pulses. Clavicular fracture was treated by esternal stabilization. We believe that in selected patients, without other serious life-threatening injures, the intimal artery injury can be treated by a conservative and now also radiologic Therapy; PTA treatment avoids morbidity and mortality associated with surgical intervention.

[The physiopathology, clinical picture and therapy of chronic intestinal ischemia]. / Fisiopatologia, clinica e terapia dell'ischemia intestinale cronica.

Between January 1982 and April 1993, 8 patients suffering from a typical clinical picture of chronic intestinal ischemia, have been observed. All these patients were symptomatic and 7 cases presented stenosing or occlusive lesions of at least 2 of the 3 splanchnic trunks. 5 of these 7 patients underwent a corrective surgical procedure. 2 patients underwent percutaneous transluminal angioplasty. One patient affected by stenosis of the coeliac trunk due to external compression caused by the median arcuate ligament of the diaphragm was not operated because the symptomatology was atypical and the other 2 splanchnic trunks were perfectly patent. Three patients died following the therapeutic procedure: a woman in whom an aorto-mesenteric bypass graft was inserted, underwent, 4 months after, an intestinal infarction due to thrombosis of the graft; another woman, whose coeliac trunk and superior mesenteric artery were thrombosed and whose inferior mesenteric artery was reimplanted on the common iliac artery, died for acute hepatic failure, after 12 months of total parenteral nourishment; a third patient, successfully submitted to PTA of the superior mesenteric artery, died after 4 months due to the occurrence of acute renal insufficiency.

[Reconstructive surgery of the abdominal aorta in a case of left-positioned inferior vena cava. Clinical case and review of the literature]. / Chirurgia ricostruttiva dell'aorta sottorenale con vena cava inferiore sinistroposta. Caso clinico e revisione della letteratura.

An unsuspected left-sided inferior vena cava (IVC) can present a formidable challenge for the surgeon attempting abdominal aortic surgery. The incidence of congenital anomalies of the post-renal (infrarenal) vena cava is approximately 3%, with double inferior vena cava most frequently occurring. The authors refer to a case of isolated left-sided vena cava in a 53 year old man who underwent an aorto-femoral bypass graft for aorto-iliac occlusive disease. On the basis of a literature review the authors recall the incidence and the embryology of this anomaly, and analyze its surgical implications, with particular reference to abdominal aortic surgery.

[The surgical prevention of pulmonary embolism. Comments on 100 patients treated by different methods]. / Prevenzione chirurgica dell'embolia polmonare. Considerazioni su 100 pazienti trattati con diverse metodiche.

A series of 100 patients suffering from deep venous thrombosis with prior episodes of pulmonary embolism or ilio-caval floating thrombi, submitted to surgery for the prevention of new embolic episodes, is analysed. Indications are discussed together with the various prevention techniques adopted over the past 5 years. Special attention is paid to the analysis of 11 patients operated on in the last 2 years by thrombectomy of the infra- and suprarenal vena cava.