Long-term outcome of cervical artery dissection

OBJECTIVE

The aim of the study is to evaluate the natural history of extracranial cervical artery dissection (CAD) including comorbidities, symptoms at presentation, recurrence of symptoms, and long-term outcome following different treatment approaches.

METHODS

A retrospective review of patients treated for acute CAD was performed over a 5-year period from January 2017 to April 2022.

RESULTS

Thirty-nine patients were included in the study, 25 (64.1%) with acute internal carotid artery dissection and 14 (35.9%) with acute vertebral artery dissection. Thirty-four patients (87.1%) had spontaneous CAD, and five patients (12.8%) had traumatic CAD. The mean age of the cohort was 54.2 years. The mean time from symptom onset to presentation was 4.34 days. The most common symptoms in internal carotid artery dissection were unilateral weakness (44%), headache (44%), slurred speech (36%), facial droop (28%), unilateral paraesthesia (24%), neck pain (12%), visual disturbance (8%), and Horner's syndrome (8%). The most common symptoms in vertebral artery dissection were headache (35.7%), neck pain (35.7%), vertigo (28.57%), ataxia (14.28%), and slurred speech (14.28%). The imaging modalities used for diagnosis included computed tomography angiography (48.7%), magnetic resonance angiography (41%), and duplex ultrasound (10.2%). In patients with carotid artery dissection, 57% had severe stenosis, 24% had moderate stenosis, and 20% had mild stenosis. All patients treated were managed conservatively with either anticoagulation or antiplatelets. Long-term clinical follow-up was available for 33 patients (84.6%). Thirty patients (90.9%) reported complete resolution of symptoms, and three patients (9%) reported persistent symptoms. Anatomic follow-up with imaging was available for 17 patients (43.58%). Thirteen patients (76.47%) had complete resolution of dissection, two patients (11.76%) had partial resolution of dissection, and two patients (11.76%) had persistent dissection. There was one death unrelated to CAD in a multi-trauma patient. There were four early recurrent symptoms in the first 3 to 8 weeks post discharge. The mean follow-up time was 308.27 days.

CONCLUSIONS

The majority of CADs can be managed conservatively with good clinical and anatomical outcome and low rates of recurrence.

The Presence of a High Peak Feature Within Low-Average Shear Stimuli Induces Quiescence in Venous Endothelial Cells

Wall shear stress (WSS) is an important stimulus in vascular remodelling and vascular lesion development. The current methods to assess and predict the risk associated with specific unsteady WSS consider the WSS mean values or the presence of reverse phases described by the oscillatory shear index. Recent evidence has shown that the accuracy of these methods is limited, especially with respect to the venous environment. Unsteady WSS are characterised by several features that may individually affect endothelial cells. Consequently, we assessed the effects of averaged WSS (TAWSS), temporal WSS gradient (TWSSG), maximum WSS (WSS peak) and reverse phase (OSI) by applying different WSS profiles to venous EC in-vitro, using a real-time controlled cone-and-plate cell-shearing device for 24 h. We found that TWSSG and WSS peak affect cell elongation and alignment respectively. We also found that the WSS waveforms with a peak of 1.5 Pa or higher significantly correlate with the induction of a protective phenotype. Cell phenotype induced by these high peak waveforms does not correlate to what is predicted by the hemodynamic indices currently used. The definition of reliable hemodynamic indices can be used to inform the computational models aimed at estimating the hemodynamic effects on vascular remodelling.

On the effect of computed tomography resolution to distinguish between abdominal aortic aneurysm wall tissue and calcification: A proof of concept

PURPOSE

The purpose of this study is to determine the optimal target CT spatial resolution for accurately imaging abdominal aortic aneurysm (AAA) wall characteristics, distinguishing between tissue and calcification components, for an accurate assessment of rupture risk.

MATERIALS AND METHODS

Ruptured and non-ruptured AAA-wall samples were acquired from eight patients undergoing open surgical aneurysm repair upon institutional review board approval and informed consent was obtained from all patients. Physical measurements of AAA-wall cross-section were made using scanning electron microscopy. Samples were scanned using high resolution micro-CT scanning. A resolution range of 15.5-155μm was used to quantify the influence of decreasing resolution on wall area measurements, in terms of tissue and calcification. A statistical comparison between the reference resolution (15.5μm) and multi-detector CT resolution (744μm) was also made.

RESULTS

Electron microscopy examination of ruptured AAAs revealed extremely thin outer tissue structure <200μm in radial distribution which is supporting the aneurysm wall along with large areas of adjacent medial calcifications far greater in area than the tissue layer. The spatial resolution of 155μm is a significant predictor of the reference AAA-wall tissue and calcification area measurements (r=0.850; p<0.001; r=0.999; p<0.001 respectively). The tissue and calcification area at 155μm is correct within 8.8%±1.86 and 26.13%±9.40 respectively with sensitivity of 87.17% when compared to the reference.

CONCLUSION

The inclusion of AAA-wall measurements, through the use of high resolution-CT will elucidate the variations in AAA-wall tissue and calcification distributions across the wall which may help to leverage an improved assessment of AAA rupture risk.

True Ulnar Artery Aneurysm in the Proximal Forearm: Case Report and Literature Review

BACKGROUND

Ulnar artery aneurysms are rare with less than 150 previously reported. Previously ulnar aneurysms have been most commonly noted as occurring in the distal ulnar artery close to the palmar arch.

METHODS

We present the case of a 47-year-old male with a background history of human immunodeficiency virus (HIV) who attended our outpatient clinic with symptoms of distal embolization from a proximal ulnar artery aneurysm.

RESULTS

Preoperatively, the aneurysm was thought to arise from the distal brachial artery, and only intraoperatively was the diagnosis of ulnar aneurysm made. The aneurysm was excised, and a reverse vein bypass graft anastomosed end to side on the brachial artery, and end to end on the distal ulnar. True ulnar artery aneurysms also involving the more proximal ulnar artery have been previously reported associated with vasculitic disorders. HIV has been previously associated with aneurysm formation in a number of anatomical locations. This case is noteworthy as it reports on the presentation and successful operative management of a true ulnar artery aneurysm arising in the proximal forearm in the setting of HIV, which has not been previously reported in medical literature.

CONCLUSIONS

We present successful operative management of a true ulnar aneurysm in the proximal forearm using a reverse venous interposition bypass. Diagnosis of a proximal ulnar artery aneurysm may represent a diagnostic challenge given its rarity as it may mimic brachial artery aneurysm.

Patient knowledge of peripheral vascular disease in an outpatient setting: an Achilles heel?

Peripheral vascular disease (PVD) has numerous modifiable risk factors. This study aimed to establish patients' awareness of risk factors and causes of PVD and their understanding of mechanisms of secondary prevention. A prospective survey of awareness of PVD among patients attending a tertiary vascular clinic for management of peripheral vascular disease was undertaken. Institutional review board approval was granted. Statistical analysis was performed using SPSS version 18.0 software. There was a 100% response rate, with 97 participants (53 male). Seventeen patients (19%) reported an interval of greater than six months from the onset of symptoms to first seeking medical attention with their General Practitioner. Only 19 (20%) could correctly identify 3 or more risk factors for peripheral vascular disease. Patients have limited awareness of PVD and its consequences. Educational initiatives are needed to encourage patients to seek early medical attention and raise awareness of modifiable risk factors in the community.

Acute aortic occlusion in a patient with heparin-induced thrombocytopenia treated by thrombectomy

INTRODUCTION

Heparin-induced thrombocytopenia syndrome (HITS) is an infrequent complication of heparin anticoagulation.

CASE REPORT

We present the case of a 44-year-old male who was admitted with acute ischaemia of his right lower limb. He was initially treated with unfractionated heparin and thrombolysis, but subsequently developed acute aortic thrombosis 8 days following initiation of heparin therapy. This was treated with bilateral per-femoral thrombectomy with curative result.

CONCLUSION

This case report draws the attention of surgeons to the difficulties in diagnosing HITS and highlights the multidisciplinary management of a complicated case of acute ischaemia.

Femoral shaft perforation at arthroplasty: to treat or not to treat

Femoral shaft perforation at total hip arthroplasty is a complication that is being noted more frequently, and it is often associated with femoral shaft fracture below the prosthesis. This study examines the anatomic and biomechanical effects of femoral shaft perforation at arthroplasty, and the effects of supporting the perforated bone with Partridge plates and bands. Two models, pig femora and Pedilen cylinders, were employed. Testing the bone models to failure in tensile mode showed that the perforations weakened the bone and that the Partridge plates and bands decreased the weakening effects of the perforation. The strengthening effect of the Partridge plates and bands on the bone with a perforation, allied with the presence of an internal splint in the event of a fracture through the perforation, suggests the benefit of using Partridge plates and bands if a cortical perforation is found at arthroplasty and revision is not feasible.

The mechanical effects of femoral shaft perforation at total hip replacement

Perforation of the femoral shaft at total hip arthroplasty is a complication which is being reported more frequently. It has been suggested that the presence of bone cement in the perforation decreases the weakening effect of the perforation, but the mechanical basis for this belief is dubious. The anatomy of perforation was studied by cadaver dissection and its mechanical consequences were assessed in two models using Pedilen, a polyurethane foam, and pig femora. It was found that cement in a hole in bone decreased the weakening effect of the hole to tensile stress.