Continued growth of and increased symptoms from a thrombosed giant aneurysm of the vertebral artery after complete endovascular occlusion and trapping: the role of vasa vasorum. Case report

A 58-year-old woman harboring a partially thrombosed giant aneurysm of the vertebral artery (VA) presented with lower cranial nerve palsies and cerebellar ataxia. The authors initially attempted to reduce the mass effect by obliterating the lumen of the aneurysm as well as by trapping of the parent artery with coils. Although there was no angiographically demonstrated evidence of filling, the aneurysm continued to enlarge. Magnetic resonance imaging revealed a marked enhancement around the packed coils close to the neck of the aneurysm. Aneurysmectomy and removal of the coils were performed and resulted in an almost complete cure of the patient's symptoms. Interestingly, at the time of resection, a marked development of vasa vasorum on the occluded VA and the neck of the aneurysm was noted. When the occluded VA was cut, there was blood oozing through the coils packed within its lumen on the side where the aneurysm lay. Histological examination showed the presence of inflammatory cells and neovascularization of a partially organized thrombus around the packed coils in both the aneurysm and occluded VA. The proliferation of vasa vasorum was also recognized histologically. This unique case provides insight into the growth mechanisms of a partially thrombosed giant aneurysm after an apparently complete occlusion by endovascular treatment, especially the role of vaso vasorum on the occluded parent artery in the dynamic process of neovascularization in the incomplete organization of thrombus around the packed coils.

[The role of vascular endothelial growth factor (VEGF)]

The authors present the role of VEGF in microaneurysm formation, blood-retinal barrier breakdown, development of capillary nonperfusion and retinal neovascularization in pathogenesis of diabetic retinopathy. Inhibitors of VEGF in treatment of diabetic retinopathy are presented.

Extensive dynamics in location, shape, and size of aneurysms in a patient with idiopathic retinal vasculitis, aneurysms, and neuroretinitis (IRVAN) syndrome. Idiopathic retinal vasculitis, aneurysms, and neuroretinitis

PURPOSE

To describe an unusual case of idiopathic retinal vasculitis, aneurysms, and neuroretinitis (IRVAN) syndrome with rapid dynamics in the number and appearance of the aneurysms.

DESIGN

Observational case report.

METHODS

Clinical and angiographic data of the patient were reviewed.

RESULTS

In the course of only 6 months, preexisting retinal aneurysms resolved while new ones appeared. Changes were observed in the shape and size of preexisting lesions. The resolution of lesions in eyes previously untreated by laser is reported for the first time.

CONCLUSIONS

Vascular lesions in IRVAN syndrome may show an unusually rapid turnover. The resolution of aneurysms is a part of the natural course of the disease and may occur without previous retinal laser photocoagulation.

Brain tissue oxygenation monitoring supplementary to somatosensory evoked potential monitoring for aneurysm surgery. Initial clinical experience

The object of the study was to evaluate brain tissue oxygenation (p(ti)O2) for intra-operative monitoring of critical ischemic events during early cerebral aneurysm surgery of the anterior circulation supplementary to somatosensory evoked potentials (SEPs). P(ti)O2 was continuously evaluated during surgery for an intracranial aneurysm in 28 patients. Standard cortical SEP monitoring was simultaneously performed. The two monitoring methods were compared by evaluating their respective responses to intra-operative events (particularly temporary vessel occlusion), clinical and neuroradiological outcome. P(ti)O2 and SEPs were reliably used for monitoring in 16 patients. Seven patients were excluded due to too high or too low p(ti)O2 readings or initial absence of SEPs (six patients). Of 64 intra-operative events 19 events (eight patients) were associated with a significant decrease in p(ti)O2 (below 10 mmHg), 22 events (13 patients) were associated with a significant change in SEP amplitude (< 50% decrease related to baseline). Temporary vessel occlusion (six SEP andp(ti)O2 changes each in eightpatients) and surgical dissection were most likely to be followed by significant changes in a monitoring method. Intra-operative p(ti)O2 was found to be a safe, rapid method for documenting ischemic events. P(ti)O2 was found to supplement SEP monitoring. The use of p(ti)O2 measurement as a routine monitoring method in aneurysm surgery is limited by its focal spatial resolution. Nevertheless, it might be helpful as an adjunct in situations when SEPs are absent at baseline, in aneurysms when parent vessel anatomy is complex or if temporary vessel occlusion is planned.

Extracranial head and neck circulation aneurysms in a case of polyarteritis nodosa

Polyarteritis nodosa (PAN) is a rare systemic necrotising medium vessel vasculitis. The hallmark of this condition is aneurysms which are seen in visceral arteries. Aneurysms of extracranial neck and head vessels are rare. We describe a case of PAN who had such aneurysms together with characteristic aneurysms in the mesenteric circulation.

Reversal of pulmonary hypertension after ligation of a brachiocephalic arteriovenous fistula

The arteriovenous (AV) fistula is the access method of choice for long-term hemodialysis according to DOQI guidelines. Among the recognized complications of upper extremity AV fistulae fashioned for hemodialysis are infection, aneurysm formation, and high-output left ventricular failure. We describe a novel cardiopulmonary complication--secondary pulmonary hypertension resulting from an aneurysmal brachiocephalic AV fistula. The clinical presentation, investigation, management, and pathophysiology of this complication are discussed.

Changes of flow characteristics by stenting in aneurysm models: influence of aneurysm geometry and stent porosity

An endovascular technique using a stent has been developed and successfully applied in the treatment of wide neck aneurysms. A stent can facilitate thrombosis in the aneurysm pouch while maintaining biocompatible passage of the parent artery. Insertion of the stent changes the flow characteristics inside the aneurysm pouch, which can affect the intra-aneurysmal embolization process. The purpose of this study is to clarify the velocity and wall shear stress changes that are caused by stenting in fusiform and lateral aneurysm models. We used a flow visualization technique that incorporated a photochromic dye in order to observe the flow fields and measure the wall shear rates. The intra-aneurysmal flow motion was significantly reduced in the stented aneurysm models. Coherent inflow along the distal wall of the aneurysm was diminished and inflow was distributed along the pores of the stent wall in the stented models. Also, sluggish intra-aneurysmal vortex motion was well maintained in the stented aneurysm models during the deceleration phase. A less porous stent generally reduced the intraneurysmal fluid motion further, but the porosity effect was not significant. The magnitude and pulsatility of the wall shear rate were reduced by stenting, and the reductions were more significant in the lateral aneurysm models compared to the fusiform aneurysm models. The hemodynamic changes that were observed in our study can help explain the efficacy of in vivo thrombus formation caused by stenting.

True giant common hepatic artery aneurysm associated with obstructive jaundice: a case report

The appropriate treatment for extrahepatic hepatic artery aneurysms remains controversial, with arguments for and against embolization. We describe a case of a giant true aneurysm of the common hepatic artery associated with obstructive jaundice of nonhemobilia origin. The patient, a 49-year-old previously healthy man, presented with upper midepigastric pain, jaundice, and low-grade fever. The diagnosis of the aneurysm was mainly based on computed tomography scan findings. The aneurysm was successfully embolized using wire coils, and the patient was operated on for acute abdomen. Necrotizing acalculus cholecystitis was found, and cholecystectomy followed by aneurysmectomy without hepatic artery reconstruction was performed. The jaundice subsided spontaneously, and the patient was discharged in good condition. Giant common hepatic artery aneurysms can be managed by either surgery or embolization. In the absence of liver ischemia there is no need for common hepatic artery reconstruction unless a bilioenteric bypass has to be performed to resolve the issue of jaundice. If the latter is required, reconstruction of the hepatic artery might be justifiable to maximize the blood supply to the bile duct.

Intra-aneurysmal pressure after incomplete endovascular exclusion

PURPOSE

An endoleak results from the incomplete endovascular exclusion of an aneurysm. We developed an experimental model to analyze hemodynamic changes within the aneurysm sac in the presence of an endoleak, with and without a simulated open collateral branch.

METHODS

With a latex aneurysm model connected to a pulsatile pump, pressures were measured simultaneously within the system (systemic pressure) and the aneurysm sac (intrasac pressure). The experiments were performed without endoleak (control group) and after creating a 3.5-mm (group 1), 4.5-mm (group 2), and 6-mm (group 3) diameter orifice in the endograft, simulating an endoleak. Pressures were also registered with and without a patent aneurysm side branch.

RESULTS

In each endoleak group, the intrasac diastolic pressure (DP) and mean pressure (MP) were significantly higher than the systemic DP and MP (P =.01, P =.006, and P =.001, respectively), although the pressure curve was damped. The presence of an open side branch significantly reduced the intrasac DP and MP.

CONCLUSION

In this model, intrasac pressures were significantly higher than systemic pressures in the presence of all endoleaks, even the smallest ones. Intrasac pressures higher than systemic pressure may pose a high risk for aneurysm rupture. Although patent side branches significantly reduce these pressures, the aggressive management of an endoleak should be pursued.

Multi-detector row CT angiography of lower extremity arterial inflow and runoff: initial experience

PURPOSE

To assess the patterns of lower extremity arterial inflow and runoff opacification with four-channel multi-detector row computed tomographic (CT) angiography in a cohort of patients with disease warranting imaging of the lower extremity arterial system.

MATERIALS AND METHODS

Twenty-four patients with symptomatic lower extremity arterial occlusive or aneurysmal disease underwent imaging with four-channel multi-detector row CT from the supraceliac abdominal aorta through the feet. Transverse sections were acquired with a 2.5-mm nominal detector width and pitch of 6.0 (3.2-mm effective section thickness) following intravenous injection of 174-185 mL of iodinated contrast medium (300 mg iodine per milliliter). In each patient, attenuation measurements were recorded in 16 arterial and 16 venous locations. In 18 patients, two radiologists assessed the detectability and stenosis degree of 21 arterial segments per patient relative to these features at conventional angiography.

RESULTS

A mean scanning time of 66 seconds was required to cover a mean of 1,233 mm, resulting in a mean of 908 transverse reconstructions. All 504 arterial segments were depicted and analyzable. Mean arterial attenuation ranged from 253 HU in the midabdominal aorta to 357 HU in the popliteal artery and 253 HU in the dorsalis pedis or posterior tibial artery measured inferior to the tibiotalar joint. Maximum mean venous enhancement (99 HU) was observed in the saphenous vein at the ankle, with all other venous stations measuring less than 74 HU.

CONCLUSION

The arteries of lower extremity inflow and runoff can be reliably depicted with minimal venous enhancement by using multi-detector row CT.

Effect of Guglielmi detachable coil placement on intraaneurysmal pressure: experimental study in canines

BACKGROUND AND PURPOSE

Treatment of ruptured aneurysms with Guglielmi detachable coils (GDCs) has been shown to prevent repeat bleeding. To assess whether GDC coiling alters aneurysmal pressure, we measured intraaneurysmal pressure in two canine types of carotid artery aneurysms before and after GDC placement.

METHODS

A 0.014-inch guidewire with a pressure transducer was inserted into parent arteries and domes of surgically created aneurysms. Intravascular static pressures were recorded before and during saline power injections (10, 20, and 30 mL over 1 and 2 s), before and after GDC placement. Common femoral arterial pressure was monitored.

RESULTS

Saline power injections reproducibly and abruptly increased pressure in parent arteries and aneurysms. Mean intraaneurysmal pressure varied (18 +/- 4 [10 mL] to 75 +/- 15 mm Hg [30 mL]), independent of injection duration. Intraaneurysmal baseline pressures were higher after GDC placement (111 +/- 10 versus 93 +/- 15 mm Hg; P =.05). Aneurysmal pressure increases with saline injections were slightly higher after GDC placement, which dampened intraaneurysmal pressure amplitude at baseline (26.5 +/- 5.6 versus 19.6 +/- 7.4 mm Hg; P =.003) and during hypertension (25.3 +/- 5.4 versus 19.8 +/- 7.5 mm Hg, P =.002). The pressure increase slope with saline injection was delayed with GDC placement (0.24 +/- 0.1 versus 0.38 +/- 0.19 s; P <.001).

CONCLUSION

Graded saline power injections into parent arteries can rapidly increase intraaneurysmal pressure. GDC treatment did not attenuate mean intraaneurysmal pressures, but both dampened the pressure amplitude and delayed pressure increases during locally induced hypertension.

Venous aneurysms of the wrist

We describe 2 cases of primary atraumatic venous aneurysm affecting the wrist. Both aneurysms were in branches of the cephalic vein in close proximity to the radial artery. The definitive treatment for these venous aneurysms was surgical excision. There was no recurrence after 9 years in case 1 and after 11 years in case 2. Modern diagnostic modalities were used, including physical examination, Doppler ultrasonography, aspiration, magnetic resonance imaging, and venography. The pathologic analysis was consistent with those venous aneurysms reported in other parts of the body. The hand surgeon should be aware of this rare condition when formulating a differential diagnosis for soft tissue masses of the wrist.

Examination of the apoptotic pathway and proteolysis in the pathogenesis of popliteal artery aneurysms

OBJECTIVES

to investigate the role of apoptosis, expression of death-promoting molecules and mediators of apoptosis in the development of popliteal artery aneurysms.

METHODS

ten popliteal artery aneurysm (PAA) specimens were obtained from patients undergoing elective surgical repair. Normal controls were popliteal arteries obtained from patients without PAA undergoing infrainguinal bypass surgery (n=8). Standard histochemistry techniques were used to assess elastic lamellae fragmentation and inflammatory infiltrate in PAA. Vascular smooth muscle cells (VSMC), macrophages, T lymphocytes, death-promoting molecules, CPP-32, Fas, p53, perforin, apoptosis-mediating Bcl-2 family proteins and apoptotic death substrate, poly(ADP-ribose) polymerase (PARP) were detected immunohistochemically. Detection of apoptosis was by TUNEL assay. Proteolytic activity was determined by 10% gelatin gel zymography.

RESULTS

there is a conspicuous disruption and fragmentation of elastic lamellae in PAA as compared to normal arteries. Increased gelatinolytic activity was observed at 92, 84, 72 and 67 kDa in PAA tissues. There is a significant decrease of VSMCs in the PAA walls (p=0.02). The control arteries had fewer CD68+ macrophages and CD3+ T cells in their media (p<0.01). There was a significant increase in the number of cells undergoing apoptosis in aneurysmal tissue than in the normal vessels, (p<0.02) as well as an increased expression of Bax, CPP-32, Fas, p53 and perforin.

CONCLUSIONS

the data confirm the architectural disruption of the PAA wall and illustrate an apparent biological response involving inflammatory infiltrate, apoptosis and signalling molecules capable of initiating cell death. In addition to compromising the mechanical integrity of the vessel wall, VSMC loss may contribute to imbalance in the protein profile, accelerating extracellular matrix degradation that could favour PAA development.

The fate of small aneurysms of the internal iliac artery following proximal ligation in abdominal aortic aneurysm repair

To assess the natural history of small internal iliac artery aneurysms (IIAA) measuring 2.0-3.0 cm in diameter, proximally ligated in association with abdominal aortic aneurysm (AAA) repair, we examined 9 of 12 patients who underwent this type of surgery. Postoperative computed tomography scanning demonstrated that three IIAAs were still patent and the other six were thrombosed. An increase in the maximum diameter from that at the time of surgery was seen in four IIAAs. One patient suffered serious complications in that a dilated IIAA caused right ureteral obstruction and subsequent hydronephrosis accompanied by unilateral renal dysfunction. This was successfully treated by resection of the IIAA. The findings of this analysis led us to conclude that small IIAAs associated with AAA repair should be treated by either endoaneurysmorrhaphy or resection of the aneurysm after both proximal and distal ligation.

Real-time observation of hemodynamic changes in glomerular aneurysms induced by anti-Thy-1 antibody

BACKGROUND

Blood flow in the microvasculature plays a pivotal role in determining the outcome of injury and repair in inflamed tissue. Real-time observation of the kidney microvasculature, including the glomerular capillary tufts, is extremely difficult because of the methodological limitations of currently available microscope optics. In the present study, we attempted to analyze hemodynamic events that occurred in vivo during microvascular regeneration following destruction of the glomerular capillary tuft, functionally and quantitatively by the use of a real-time confocal laser-scanning microscope (CLSM) system.

METHODS

A polyethylene catheter was inserted into the carotid artery to allow blood pressure measurement. Mesangiolytic lesions producing microaneurysms were induced by the injection of anti-Thy-1.1 antibody. On days 3 and 7 after antibody injection, we examined hemodynamic changes under an intravital microscope equipped with real-time CLSM in combination with a high-speed CCD video camera. To measure vessel diameter and erythrocyte velocity, rats were injected with fluorescein isothiocyanate (FITC)-labeled dextran and FITC-labeled red blood cells (RBCs).

RESULTS

On day 3 of the disease, mean arterial blood pressure was 112 +/- 5 mm Hg, which was significantly higher than that of normal rat or of rats on day 7 (93 +/- 1 and 101 +/- 9 mm Hg, respectively). Within mircroaneurysms on day 3, RBC velocity was greatly suppressed. By day 7, RBC velocity, in glomeruli with normal appearances, recovered to about half of the level seen in normal controls (430.6 +/- 284.7 microm/sec), while in narrowed glomerular tufts, it was still only 104.6 +/- 35.1 microm/sec.

CONCLUSIONS

The noninvasive procedure, using CLSM in combination with a high-speed video camera, allowed us to examine hemodynamic events quantitatively and to analyze microvascular architecture three dimensionally in the kidney. It is useful for estimating hemodynamic response and vascular regeneration in vivo and may be promising for clinical application.

Aneurysmal dilatation of the paraumbilical vein in an infant

The paraumbilical veins are one of the most common collateral pathways developing in portal hypertension. Aneurysmal dilatation of a patent paraumbilical vein is a very unusual finding. We report the first infant case of a paraumbilical vein aneurysm and its Doppler ultrasound findings.

Vascular pathology in the throwing athlete

Vascular pathology in the upper extremity of a throwing athlete comprises a spectrum of serious disorders apt to threaten the patient's career and the viability of the involved parts. Such pathology includes digital vessel thrombosis, proximal thrombosis with distal embolization, vessel aneurysm, and vessel compression, such as in thoracic outlet syndrome and quadrilateral space syndrome. This article provides a description of vascular disorders prone to result from sports activities and a review of published data relevant to throwing athletes. Recognition of vascular compromise as a cause for dead arm syndrome or painful digital dysfunction among athletes is essential to prevent the grave consequences of progressive ischemia.

Asymptomatic aneurysm of the proximal right subclavian artery: a rare ultrasound diagnosis

True aneurysms of otherwise normal subclavian arteries are uncommon peripheral vascular anomalies. Most patients with subclavian artery aneurysms are symptomatic by presenting neurologic signs. We report a young woman who had an asymptomatic true aneurysm of the right subclavian artery assumed to be of congenital origin. This case is unique in that the aneurysm was in the extremely rare anatomic location of the right supraclavicular fossa between the origins of the right subclavian artery and the vertebral artery. Aneurysms of the right subclavian artery may represent a potential pitfall in conventional gray-scale ultrasound of the neck particularly the supraclavicular fossa. Differential diagnosis includes cervical cyst, pharyngo-esophageal diverticulum, vascular anomalies, struma, enlarged lymph node, as well benign or malignant neoplasms. Color duplex ultrasound should be performed as the method of choice for further analysis of suspected aneurysms. In this report the role of B-mode ultrasound and color duplex ultrasound is discussed in relation to digital subtraction- and MR angiography in confirmation of the diagnosis.