Preliminary results of Anaconda aortic endografts: a single center study.

OBJECTIVE: To evaluate the peri-operative results of Anaconda endograft in the first 49 cases treated in a single centre. METHODS: The study was carried out prospectively on cases of infrarenal abdominal aortic aneurysm (AAA) treated with Anaconda endograft. The characteristics of the proximal aortic neck and of the iliac access vessels were considered. The following operative results were assessed: the main body oversizing, the need to correct the positioning of the main body, the use of iliac extensions, the use of ballooning, the covering of patent hypogastric arteries, the presence of endoleaks and the need for conversion. Peri-operative (30 days) mortality and morbidity were also considered. RESULTS: Of the 49 cases treated, 44 were males with a mean age of 73 years (range: 55-89 yrs; SD+/-7 yrs). The mean diameter of the AAA was 56 mm (range 45-91 mm; SD+/-11); 4 cases had common iliac aneurysms with a diameter >3 cm. The mean neck diameter and length were 23 mm (range 19-28 mm; SD+/-3) and 25 mm (range 15-50 mm; SD+/-10) respectively. An aortic neck angle between 40 degrees and 70 degrees was present in 10 cases (20%) (mean 58 degrees; SD+/-15 degrees), and 20 cases (41%) had iliac tortuosity with an angle greater than 60 degrees (mean 85 degrees; SD+/-25 degrees). There were no cases of conversion or intra-operative death. One (2%) peri-operative death occurred, for reasons not related to the endograft. There were two cases of iliac limb thrombosis. CT at one month showed 12 cases (25%) of type II endoleak. There were no cases of type I or type III endoleaks. CONCLUSIONS: The preliminary data of this series demonstrates that the Anaconda endograft has good peri-operative results in the treatment of infrarenal AAAs with a neck length not less than 15 mm.

[Refractory hypertention in a female patient with renal failure]. / Un caso di ipertensione refrattaria in donna con insufficienza renale.

We report one sixty-seven years-old female who presented with hypertension refractory to antihypertensive drugs. She had an elevated BP for approximately 15 years. In the last 8-10 months her hypertension had become difficult to control. Her BP ranged between 180/100 mmHg and 220/1220 mmHg on atenolol 100 mg once daily, methyldopa 500 mg three times daily, furosemide 25 mg twice daily, doxazosine 4 mg twice daily. When she was referred to our unit serum creatinine was 2.3 mg/dL and she had a mild proteinuria (70 mg/dL) without microematuria. Ultrasonography showed a left kidney size in the low-normal range (LD 11 cm) and a small right kidney (LD 9 cm). Renal angiography showed a severe, ostial stenosis of the left renal artery and a total thrombosis of the right renal artery with a blood supply to the right kidney provided by collateral channels. An ACE-I was added to the therapy but a sharp increase in serum creatinina (up to 6.4 mg/dL) prompted us to withdraw the drug. She underwent a renal angioplasty on the left side and a Palmaz stent was placed. The control angiography showed a good anatomical result. Three months after the manoeuvre the patient was again referred to our unit with headache, nausea vomiting and hyper-tension refractory to amlodipine 10 mg/day, doxazosine 4 mg twice a a day, atenolol 50 mg/day, furosemide 50 mg/day. A doppler ultrasonography and a magnetic resonance angiogram showed no restenosis on the treated artery. An ACE-I was again administered and BP on this drug was 145/90 mmHg after one month and 130/85 after three months. Headache, nausea and vomiting disappeared. Serum creatinina kept unchanged (2.2 mg/dL). Comment. In this case the benefit of angioplasty on blood pressure control was indirect. Apparently the manoeuvre showed no effect on blood pressure, but the angioplasty allowed us to use of an ACE-Inhibitor, without any negative effect on renal function, and thus to adequately control blood pressure.

Fluidodynamic evaluation of arteriovenous fistulae for hemodialysis.

Arteriovenous fistulae (AVF) are commonly used in dialysis treatment of uremic patients. However, many AVF create problems and have to be re-examined. Problems arise in the cannulation site and must be treated with antibiotics, and stenosis, both in the arterial and in the venous side of the AVF. In the worst case, the AVF must be replaced for treatment to continue. However, this can only be repeated once before the AVF site is no longer viable. This increases the discomfort, the morbidity and the mortality of the dialysis patient. Several kinds of AVF were studied to determine whether flow disturbances give rise to these complications. Many studies have already demonstrated the importance of hemodynamic factors in vascular disease pathogenesis. These factors include: the pulsatility of flow, the elasticity of the vessel, the non-Newtonian blood, flow behavior and, very importantly for AVF, the vessel geometry. In model studies, intimal changes have been observed in bends and bifurcations, regions of vessel construction and vessel stenosis. In these regions, blood flow changes abruptly and this contributes to arterial disease. We prepared several one-to-one, true-to-scale elastic silicon rubber models of different AVF. The AVF models were based on angiographic studies of chronic dialysis patients and on AVF from the arms of cadavers. The models had a similar compliance to that of the human blood vessel. Flow was visualized using photoelasticity apparatus and a birefringent blood-like fluid. This method is suitable to analyze the spatial configuration of flow profiles, to differentiate laminar flow from disturbed flow, and to visualize flow separation, vortex formation and secondary flow. It was found that AVF create disturbances that are not found under normal physiological flow conditions. The X-formed AVF was very unsatisfactory, creating significant flow disturbances. The AVF had high velocity fluctuations. These could lead, for example, to aneurysm formation. A better configuration would be an end-to-end AVF. However, this formation creates other complications. For example, there is not enough blood to the hand and parts of the hand lose feeling. The recommended AVF would be an end-to-side anastomosis. In this case, attention is needed for placement geometry, to minimize additional flow disturbances. Several models as well as patient angiographic studies are discussed.

Tratamiento antibiótico intratecal intraventricular en meningitis infecciosa postquirúrgica / Intrathecal-intraventricular antibiotic treatment in postoperative infectious meningitis

Realizamos una revisión de datos clínicos y microbiológicos de tres pacientes que desarrollaron infecciones postoperatorias, (dos cirugías craneales y una espinal). El tratamiento antibiótico intravenoso aislado falló, y debimos recurrir a la vía intraventricular-intratecal con buenos resultados. El tratamiento antibiótico intraventricular-intratecal aparece como una modalidad útil, en aquellas infecciones postoperatorias en que la terapia sistémica no da resultado.

Tratamiento antibiótico intratecal intraventricular en meningitis infecciosa postquirúrgica / Intrathecal-intraventricular antibiotic treatment in postoperative infectious meningitis

Realizamos una revisión de datos clínicos y microbiológicos de tres pacientes que desarrollaron infecciones postoperatorias, (dos cirugías craneales y una espinal). El tratamiento antibiótico intravenoso aislado falló, y debimos recurrir a la vía intraventricular-intratecal con buenos resultados. El tratamiento antibiótico intraventricular-intratecal aparece como una modalidad útil, en aquellas infecciones postoperatorias en que la terapia sistémica no da resultado. (AU)

Renovascular disease in diabetes mellitus: treatment by percutaneous transluminal renal angioplasty.

BACKGROUND: Diabetes mellitus is an important cause of end-stage renal failure (ESRF). Although classic diabetic nephropathy accounts for the majority of patients reaching ESRF, renovascular disease, which is frequent in such patients, plays an increasingly important role. Percutaneous transluminal renal angioplasty (PTRA) has been proven to be an efficacious measure for renal revascularization. METHODS: Ninety-nine patients with diabetes mellitus and renal artery stenosis, corresponding to 16.6% of the entire population of diabetic patients, were treated by PTRA or with the Palmaz-Schatz stent in our clinic. Technical success was achieved by PTRA in 92/99 patients, in 10 patients a Palmaz-Schatz stent was implanted. RESULTS: Hypertension was cured in eight and improved in 44 patients. In 47 patients, there was no impact on blood pressure. An improvement in renal function was evident 1 month after PTRA in 8/27 patients. A further improvement occurred in another four patients after 6 months. The re-stenosis rate was 22% after 5 years. Serious complications occurred in seven patients (one patient required surgery and two patients had regular dialysis treatment). CONCLUSIONS: Renovascular disease is an important cause of ESRF in diabetic patients. PTRA is a valid tool to revascularize renal artery stenosis and improve blood pressure control and renal function both in diabetic and non-diabetic patients.

Renal artery angioplasty for renovascular hypertension and preservation of renal function: long-term angiographic and clinical follow-up.

OBJECTIVE: Percutaneous transluminal angioplasty of stenoses of the renal artery can be used to treat hypertension and renal insufficiency. Although many studies have been published on the short-term results of this procedure, few long-term studies are available. SUBJECTS AND METHODS: One hundred ninety-five patients (123 men and 72 women 19-79 years old; mean age, 56 years) with stenosis of the renal artery and hypertension underwent renal percutaneous transluminal angioplasty at our institution. The stenosis was unilateral in 66% of patients, bilateral in 26%, and in a solitary functioning kidney in 8%. Renal insufficiency was present in 31% of patients. After renal percutaneous transluminal angioplasty, long-term clinical and angiographic follow-up was evaluated by life-table analysis. RESULTS: In patients with fibromuscular disease, blood pressure returned to normal in 57%, improved in 21%, and was unchanged in 21%. In patients with atherosclerotic stenosis, blood pressure returned to normal in 12%, improved in 51%, and was unchanged in 37%. After percutaneous transluminal angioplasty, renal function improved in 48% of patients with renal insufficiency due to bilateral stenosis or stenosis in the single functioning kidney, whereas none of the patients with unilateral stenosis of renal artery and renal insufficiency had any notable improvement. Long-term follow-up showed a high rate (82%) of patency of revascularized arteries and a low rate (21%) of hypertension recurrence at 5 years. CONCLUSION: Renal percutaneous transluminal angioplasty is useful for treating hypertension and for reestablishing renal function. Its effects on blood pressure and renal function are long-lasting in the large majority of patients.

[Color-Doppler and angioplasty in renovascular hypertension]. / Color-Doppler e angioplastica nell'ipertensione renovascolare.

Renovascular hypertension is defined as a kind of hypertension secondary to altered renal perfusion with the activation of the renin-angiotensin system. Since a large number of these patients benefits from treatment--be it medical, surgical or angioplastic--a non-invasive low-cost method allowing accurate screening was looked for. Color-Doppler was employed by many authors to evaluate renovascular hypertension, for both the early diagnosis of the condition and the evaluation of treatment results in renal artery stenoses. However, the authors agree that color-Doppler cannot play a major role in the screening of renovascular hypertension due to the various qualitative and quantitative variables not being adequately codified, to the lack of a single color-Doppler method and to the difficult comparison of the results from the different units. Nevertheless, improved results are promised by technological evolution, together with the possibility to codify color-Doppler variables more easily repeatable. B-mode units with 3.5 and 5 MHz probes were employed in the thinnest subjects. In 5-25% of cases accessory renal arteries were observed. After identifying the vessel to be studied with several spatial scans, the smallest possible sample volume (usually 3-5 mm) was positioned. The normal flowmetric range was 0.07-0.1 s: it must not exceed 0.16 s, with persistence of high diastolic flow. Some authors' criteria were followed to define either stenosis or renal artery obstruction; moreover, pulsatile flow index was considered, together with the resistive index, pulsatility index and stenosis index.

[Renal artery stenosis. Doppler color study before and after angioplasty]. / Stenosi delle arterie renali. Studio color-Doppler prima e dopo angioplastica.

Doppler flowmetry can be successfully employed to assess arterial patency after percutaneous transluminal angioplasty (PTA). The aim of this study was to assess color Doppler sensitivity in detecting renal artery stenosis prior to percutaneous angioplasty (PTRA) and vessel patency after it. Eleven patients (7 males and 4 females) affected with renal artery stenosis, unilateral in 9 cases and bilaterally in 2, underwent color-Doppler evaluation 1 day before and 7 days after PTRA. The operator was unaware of dilatation results. A total of 13 stenoses were treated. The qualitative and quantitative parameters we employed were: a) broadening of the spectrum, b) peak systolic frequency > 4000 Hz, c) stenosis index > 50%. Before PTRA, mean systolic peak at the stenosis was 7978 (range 4050-12500 Hz), while stenosis index was 71.9% (range 48-89%). After PTRA complete recovery was observed in 5 cases, no improvement in 1 and incomplete recovery in 7. Doppler results were in agreement with those of angiography in 6/13 while partial agreement only was seen in 7/13. Our results, although obtained in a small and highly selected group of patients, would seem to support the value of color-Doppler for the follow-up of patients after PTRA.

Prognostic value of captopril renal scintigraphy in renovascular hypertension.

This study evaluates the prognostic value of captopril renal scintigraphy in hypertensive patients undergoing renal artery revascularization. Preoperative studies of 51 patients were correlated with blood pressure results at 6- and 12-mo follow-up. Captopril-renal scintigraphy was carried out 1 hr after oral administration of 50 mg of captopril, using either 220 MBq of 99mTc-DTPA or 74 MBq of 99mTc-MAG3, followed by a baseline study in case of abnormal results. Evidence of amelioration or normalization in relation to captopril study was considered predictive of blood pressure control following treatment. Blood pressure response was favorable in 37 patients, but failed to show any improvement in 14. The scintigraphic test was positive in 33 patients (15 cured, 17 improved, 1 failed) and negative in 18 (3 cured, 2 improved, 13 failed). Sensitivity and specificity for renovascular hypertension was 86.5% and 93%, respectively. For blood pressure cure and improvement, the test had positive and negative predictive values of 97% and 72%, respectively. A positive preoperative captopril renal scintigraphic result is a strong predictor of hypertension curability by renal artery revascularization.

Evaluation by captopril renal scintigraphy and echo-Doppler flowmetry of hypertensive patients at high risk for renal artery stenosis.

Sixty-three hypertensive patients with probability of obstructive renal artery disease underwent both Captopril renal scintigraphy (CRS) and echo-Doppler flowmetry (EDF) before undergoing renal angiography. Angiography revealed renal artery stenosis (RAS) in 42 patients (unilaterally in 26 and bilaterally in 16). The sensitivity and specificity in the identification of RAS > or = 50% were 90% and 94%, respectively for Captopril renography, and 85% and 78% for echo-Doppler flowmetry. Captopril renography correctly identified stenoses greater than 50%, which is usually held to be the limit of hemodynamic significance. While the Doppler examination was more sensitive than Captopril renography (sensitivity 79% versus 64%) in the detection of all degrees of RAS, less information on the functional significance of RAS was provided. Both CRS and EDF could be usefully employed to assess kidney perfusion, but their appropriate clinical use must take into account inherent differences between the two techniques.

[Percutaneous nephrostomy in neoplasm patients: when?]. / Nefrostomia percutanea nei pazienti neoplastici: quando?

The management of cancer patients with a lesion in its end stage is a clinical problem a satisfactory solution to which has not been found yet, because of the ethical and legal problems involved. The authors analyzed the survival rates of 218 patients with advanced neoplastic disease and obstructive renal failure who had undergone external/internal urinary diversion. One month after the procedure 20% of the patients were dead. The figure rose to 75% at 6 months and reached 98% at one year. Urinary diversion in cancer patients with renal failure is aimed not only at avoiding death and assuring a prolonged survival, but also at providing a good quality of life. Several clinical criteria are therefore analyzed which are used in the selection of patients to submit to nephrostomy. The most important factors seem to be the actual stage of the tumor, its primary location, the possibility of an effective antineoplastic therapy, and the patient's consent. Randomized long-term studies are still necessary to analyze not only survival rates but also quality of life after urinary diversion for obstructive renal failure.

[Duplex and Doppler color echocardiography for the study of renovascular hypertension. Comparison with arteriography]. / Eco-duplex e color-Doppler nello studio dell'ipertensione reno-vascolare. Confronto con l'arteriografia.

Doppler US was employed to examine 46 patients with suspected renovascular hypertension (RVI) to detect stenosis/occlusion of the renal artery. In 25 cases duplex-Doppler technique was used, in 19 color-Doppler US, and 2 patients were examined with both methods. Doppler US was always performed before angiography which was considered as the reference gold standard. Using duplex-Doppler US, the diagnosis of renal artery stenosis was based on qualitative (spectral analysis of the waveform and absence of flow signal in cases of renal artery occlusion), and semiquantitative parameters (resistive index). Diagnostic accuracy of duplex US--which was compared with that of angiography--was 83%, its sensitivity was 91.6%, and specificity was 85%. With color-Doppler, two additional quantitative parameters were used (peak systolic frequency shift at the stenosis and stenosis index). In this group of patients sensitivity was 70%, specificity was 100%, and accuracy 85%. The good diagnostic yield of the method is counter-balanced by some limitations--e.g., operator dependence and long examination time (30-40 minutes, especially with duplex US). In the authors' opinion, Doppler technique can be used in the diagnosis of RVI, even though further study is necessary to exactly define diagnostic parameters, and to verify reproducibility and both inter- and intra-observer repeatibility. Technological progress may in the future reduce both difficulty and time of the examination.

Use of technetium-99m-MAG3 for renal scintigraphy after angiotensin-converting enzyme inhibition.

Technetium-99m-mercaptoacetyltriglycine (99mTc-MAG3) was tested in 82 hypertensive patients submitted to renal scintigraphy 1 hr after oral premedication with 50 mg of Captopril. Baseline studies were obtained only for those patients showing abnormal findings in the provocative study. All patients underwent renal arteriography. Sensitivity and specificity for the detection of renal artery stenosis (RAS) greater than 50% were 89% and 91%, respectively. After Captopril administration, tracer parenchymal transit time increased significantly in ischemic kidneys (334 +/- 93 sec in baseline conditions versus 468 +/- 96 sec after Captopril, p less than 0.001) but not in kidneys with no RAS or RAS less than 50% (243 +/- 46 sec versus 271 +/- 95 sec, p = ns). False-positive responses were mostly bilateral and associated with a marked decrease in blood pressure. Technetium-99m-MAG3 is an effective compound for detecting RAS greater than or equal to 50% with Captopril renal scintigraphy. Performing the provocative test as a first step considerably reduced the number of scintigraphic studies required.

Evaluation of hypertensive patients by means of captopril enhanced renal scintigraphy with technetium-99m DTPA.

One-hundred five hypertensive patients underwent conventional renal scintigraphy followed 2 or 3 days later by Captopril-enhanced renal scintigraphy, performed 1 hr after premedication with 50 mg of Captopril per os. All patients were then submitted to renal arteriography, performed within 15-30 days. Fifty-five patients had no renal artery stenosis, 29 had unilateral disease, and 21 bilateral. Overall, 34/37 patients were diagnosed by the provocative test as having at least one renal artery affected by a stenosis greater than 50%. Of those with no stenosis (n = 55) or stenosis less than 50% (n = 13) only two cases were falsely positive. Thus sensitivity was 92% and specificity 97%. For single kidney identification with stenosis greater than 50%, sensitivity of renal scintigraphy after Captopril administration was 94% and specificity 98%. Captopril enhanced renal scintigraphy is thus suggested as the first test to be performed in hypertensive patients referred for renal scintigraphic studies. Only those cases with equivocal results require a baseline study for better assessment.