Peter Waldenberger

PTA versus Palmaz Stent Placement in Femoropopliteal Artery Obstructions: A Multicenter Prospective Randomized Study

PURPOSE To evaluate if stent placement is superior to percutaneous transluminal angioplasty (PTA) in the treatment of chronic symptoms in short femoropopliteal arterial lesions. MATERIALS AND METHODS One hundred fifty-four limbs in 141 patients who ranged in age from 39 to 87 years (mean age, 67 years) were randomized to PTA (n = 77) versus PTA followed by implantation of Palmaz stents (n = 77). Inclusion criteria were patients with intermittent claudication (n = 108, Society of Vascular Surgery/International Society of Cardiovascular Surgery [SVS-ISCVS] categories 1-3) or chronic critical limb ischemia (n = 46 with either ischemic rest pain [category 4] or minor tissue loss [category 5]), short stenosis or occlusion (lesion length < or = 5 cm), and at least one patent run-off vessel at angiography. Follow-up included clinical assessment, measurement of ankle/ brachial index (ABI), color duplex ultrasound, and/or angiography at 6 or 12 months. Angiographic follow-up between 12 and 36 months was available in 46 limbs (29.9%). RESULTS In the PTA group, initial technical success was achieved in 65 of 77 limbs (84%) versus 76 of 77 (99%) limbs in the stent group (chi2 value = 0.009). Overall, major complications occurred in 3.9% (n = 6); n = 4 in the PTA group compared to n = 2 in the stent group. There was no difference between groups of treatment: hemodynamic/clinical success at 1 and 2 years in the PTA group was 72% and 65% versus 77% and 65% in the stent group (Gehan P value = .26). The cumulative 1- and 2-year angiographic primary patency rates were 63% and 53%, respectively, for both groups. The secondary 1- and 2-year angiographic patency rates were 86% and 74% in the PTA group versus 79% and 73% in the stent group (P = .5). CONCLUSION After stent placement, the primary success rate was significantly higher than after PTA. However, 1-year angiographic and clinical/hemodynamic success was not improved.

Sonographic detection of radial nerve entrapment within a humerus fracture.

Radial neuropathy is frequently associated with fracture of the middle third of the humerus owing to the course of the nerve adjacent to the humeral shaft. The prevalence varies from 2 to 18% of humeral fractures. The therapeutic management is still controversial. Some authors recommend initial surgical exploration, whereas others prefer observation and intervention only if the injured nerve failed to recover after a period of more than 4 months. According to the literature, verification of an entrapped radial nerve in a fracture gap requires surgical exploration, but diagnostic tools to verify the existence of a pathologic condition are limited. We describe the sonographic findings of an entrapped radial nerve and review the literature regarding diagnosis and treatment of entrapped radial nerve in cases of humeral fracture.

Serial CT Volume Measurements after Endovascular Aortic Aneurysm Repair

Purpose: To evaluate the efficacy of transluminal stent-graft placement in aortic aneurysms using postoperative enhanced spiral computed tomographic (CT) volumetric measurements of the aneurysm sac, the intra-aneurysmal vascular channel (IAVC), the thrombus, and the stent-graft. Methods: Among 53 patients (45 men; mean age 74 years, range 59–85) who underwent elective endovascular aortic aneurysm repair, 37 patients with 27 abdominal and 10 thoracic aortic aneurysms completed at least a 6-month follow-up that included computerized CT volumetric analysis prior to discharge and at 3, 6, 12, 24, and 36 months. A variety of bifurcated (n = 23) and tube (n = 14) stent-grafts were observed for signs of endoleak and aneurysm enlargement. Results: Mean follow-up was 16 months (range 6–48). Total aneurysm volumes and thrombus volumes decreased, whereas IAVC and stent-graft volumes increased over time. Between the postoperative and 12-month imaging studies, reductions in total aneurysm (p = 0.011) and thrombus (p < 0.001) volumes were significant. No statistically significant difference in volume changes for the aneurysm sac (p = 0.555) or the thrombus (p = 0.920) was found when comparing the 24 patients without primary leak to the 12 with primary type-II leak. In all 5 cases with secondary leak, the volume of the aneurysm sac increased after initial shrinkage. Conclusions: Postoperative CT volumetric analysis is an effective tool for evaluating the outcome of endovascular aortic aneurysm repair. Thrombus volume measurements are more accurate than total aneurysm volumes. In patients in whom contrast agents are contraindicated, volume measurements can also be obtained without the use of contrast.

Serial CT Volume and Thrombus Length Measurements after Endovascular Repair of Stanford Type B Aortic Dissection

Purpose: To evaluate the outcome of stent-graft placement in Stanford type B aortic dissection using contrast-enhanced spiral computed tomographic (CT) measurements of true and false lumen volumes and thrombus length. Methods: Among 18 consecutive patients (13 men; mean age 60 years, range 44–79) who underwent endovascular repair of Stanford type B dissection, 12 completed at least a 12-month follow-up, which included CT measurements of true and false lumen volumes and thrombus lengths prior to discharge and at 6 and 12 months postimplantation. Volumes were assessed in 3 different aortic segments (A1, A2, A3) extending from the proximal attachment site of the prosthesis to the aortic bifurcation. In addition, thrombus length was measured to evaluate the influence of clot formation on outcome of the false lumen volume. Results: Mean follow-up was 27 months (range 12–60). Within 12 months, mean true lumen volumes showed statistically significant increases in the A1 (p<0.001) and A2 (p=0.003) segments; false lumen volumes showed a significant decrease in the A1 segment (p=0.002) but an insignificant increase in the A2 segment. No substantial volume changes were observed in the A3 segment. Extension of clot formation in the false lumen varied among patients and over time. Length of stent-grafts, percentage of stented dissection length, or visceral arteries originating from the false lumen did not significantly influence thrombus development, nor did these parameters or thrombus formation distal to the prosthesis have a relationship to false lumen volumes. Conclusions: Volumetric analysis after endovascular repair of Stanford type B dissection shows optimal technical outcome in the stented segment, whereas the false lumen in the segment immediately adjacent to the stent-graft seems to be a vulnerable area. Extension of clot formation beyond the endograft seems to be no reliable predictor of outcome.

Does stent overlap influence the patency rate of aortoiliac kissing stents

Purpose: To determine if the position of kissing stents in the distal aorta has any influence on the patency rate. Methods: A retrospective review was conducted of 41 patients (22 men; median age 60.8 years, range 44–86) electively treated for atherosclerotic aortoiliac occlusive disease with angioplasty and kissing stents between January 1997 and January 2005. Two patient groups were defined by reviewing postinterventional anteroposterior radiograms: (1) patients in whom the proximal end of the kissing stents overlapped more than half of their angiographic width within the aorta (“crossing” group) and (2) patients in whom the proximal ends of the stents overlapped half of their width or less (“non-crossing” group). Results: At 2 years, the primary and assisted primary patency rates by life-table analysis were 60.8% and 69.4%, respectively, for the 35 patients included in the life-table analysis. There was no significant difference between the 16-patient “crossing” group and the 19-patient “non-crossing” group in terms of the baseline demographic, morphological, and procedural variables. The primary and assisted primary patency rates at 2 years for the “non-crossing” group were significantly higher (94.1% and 100%, respectively) compared to 33.2% and 45.3%, respectively, for the “crossing” group (p=0.01). Conclusions: Failure of kissing stents in the aortic bifurcation may be significantly increased by the overlap of the free proximal stent ends in the distal aorta.

Percutaneous management of a hepatic artery aneurysm: bleeding after liver transplantation.

In this artical we present an unusual case of hepatic artery aneurysm bleeding due to a hepatic artery thrombosis after liver transplantation. The patient developed a recurrent hepatic artery thrombosis leading to severe graft failure in four consecutive liver transplantations. While being evaluated for a fifth transplant, stabilization of the clinical situation was attempted by interventional therapy. The first intervention was to place a stent into the hepatic artery to prevent further ischemic damage. This failed to improve graft function, but unfortunately led to the development of a pseudoaneurysm at the distal end with a subsequent rupture into the biliary tree. Bleeding was treated successfully by direct puncture and coil embolization of the aneurysm. In addition, the patient demonstrated a hemodynamically relevant portal vein stenosis on the CT scan. Stenting of the portal vein markedly improved graft function. After extensive investigations, a paroxysmal nocturnal hemoglobinuria was found to be the underlying cause of the recurrent hepatic artery thrombosis. Here we suggest that hepatic artery aneurysm bleeding is a rare but potentially fatal complication that can be successfully treated by percutaneous coil embolization. Additionally, we propose that stenting of the portal vein can lead to a significant improvement of the graft perfusion even though the hepatic artery remained occluded.

Transjugular intrahepatic portosystemic shunt (TIPS) augments hyperinsulinemia in patients with cirrhosis

BACKGROUND/AIMS Cirrhosis of the liver is characterized by glucose intolerance and hyperinsulinemia. Both increased insulin secretion and decreased insulin clearance appear to contribute to hyperinsulinemia in cirrhotic patients. A decrease in hepatic insulin extraction rate may be due either to hepatocellular dysfunction or to portosystemic shunting with decreased first-pass insulin clearance. METHODS To specifically address the contribution of portosystemic shunting to the pathogenesis of hyperinsulinemia in cirrhotic patients, we analyzed glycemic control and insulin levels in fasting serum in 23 cirrhotic patients before and after transjugular intrahepatic portosystemic shunt (TIPS). RESULTS Compared to respective values in healthy controls, C-peptide, insulin and proinsulin concentrations at baseline were increased by 340%, 120% and by 100% in cirrhotic patients (all p<0.05). In cirrhotic patients insulin levels before TIPS averaged 104+/-73 pmol/l and increased by more than 50% to 163+/-118 pmol/l after TIPS (p<0.01), whereas levels of C-peptide and proinsulin showed no significant change. Glucose and fructosamin levels also remained unchanged after TIPS. CONCLUSION Our data demonstrate that TIPS does not impair glycemic control in cirrhotic patients and that an increase in portosystemic shunting augments hyperinsulinemia, most likely by decreasing hepatic insulin clearance.

Investigation of cerebrovascular disease with mr angiography: comparison of volume rendering and maximum intensity projection algorithms: initial assessment

Abstract. We assessed the clinical utility of the volume-rendering (VR) algorithm as a postprocessing technique of intracranial magnetic resonance angiography (MRA) for the evaluation of cerebrovascular disease in comparison with the maximum intensity projection (MIP) algorithm. VR and MIP images were compared with digital subtraction angiography (DSA). Volume-rendered views improved the perceptibility of intracranial vasculature and consequently augmented diagnostic confidence, improved the characterization of underlying vascular pathologies, and facilitated image interpretation. Volume rendering has the potential to expand the role of cerebral MRA in the diagnostic investigation and treatment planning of cerebrovascular disease.

Emergency endovascular treatment of traumatic aortic arch rupture with multiple arch vessel involvement.

Purpose: To report successful endovascular stent-graft placement for emergency treatment of a complex traumatic injury involving the aortic arch and multiple arch vessels. Case Report: An 81-year-old man underwent stent-graft placement for a complex traumatic vascular injury. Computed tomography on admission documented a dissection along the course of the aortic arch, intramural hematoma along the ascending aorta, dissection of the innominate artery, and a right subclavian artery pseudoaneurysm. The dissection of the aortic arch and the pseudoaneurysm of the right subclavian artery were treated immediately, the dissection of the innominate artery 7 days later. The patient did not develop any complications. Follow-up studies performed prior to discharge and at 6 and 12 months after the interventions showed successful repair of the complex vascular injuries. Conclusions: Traumatic injury of the aortic arch with multiple arch vessel involvement can be treated effectively by means of stent-graft placement.

Hyperperfusion Syndrome of the Left Hand after Percutaneous Transluminal Angioplasty and Stent Placement in a Subclavian Artery Stenosis

PERCUTANEOUS transluminal angioplasty (PTA) has been described as an effective and safe procedure for treatment of symptomatic subclavian artery stenosis. The complication rate is low, the most frequent complication being embolism to the vertebral and digital arteries (1–5). Hyperperfusion syndrome (HS) and hyperemia are well known in reconstructive arterial surgery in chronic arterial occlusive disease, in particular carotid endarterectomy and bypass surgery of the lower limb (6–9). This phenomenon was also described after PTA of carotid and superficial iliac arteries, respectively (10,11). Clinical symptoms regarding the lower limb consist of unspecific swelling developing between day 1 and 7 after PTA. Clinical symptoms in PTA of carotid arteries develop from increased blood flow and present as headache and vomiting. We report a case of HS of the left hand and fingers after successful PTA and stent placement in a symptomatic highgrade stenosis of the subclavian artery.