Anterior spinal fusion (ALIF/OLIF/LLIF) with lumbosacral transitional vertebra: A systematic review and proposed treatment algorithm

•Key anterior approaches differences in LSTV include vascular (aortic bifurcation/iliocaval confluence), muscular (psoas) and osseus anatomy (inter-crestal tangent/pubic symphysis), when compared to non-LSTV.•There are increased surgical deviations but not significantly greater complications for anterior approaches in LSTV.•Vascular awareness while accessing L45 will be in the presence of a more cephalad ABF and ICC with sacralized L5, and access to the deeper L56 level will be in the presence of a more caudal ABF and ICC in lumbarized S1.

Comprehensive mechanical & metabolic imaging of abdominal aortic aneurysm with 4D flow/ FDG PET on an integrated PETMRI: a feasibility study

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): NIHR Biomedical Research Centre, University College London Hospitals.

Background

A number of non-invasive imaging derived parameters have been implicated in the development and progression of abdominal aortic aneurysm, although the mechanism, and relationships of many of these are yet to be precisely determined.  Mechanical parameters can now be studied using 4D phase contrast magnetic resonance (PCMR), and inflammatory cellular activity can be detected with FDG PET.

Purpose

It may be postulated that inflammation of the aortic wall may be the intermediary at the tissue level linking mechanical wall shear stress (WSS) to aneurysm progression. It may be feasible to study 4D PCMR and FDG PET at the same patient visit on a PETMRI platform, with the potential to enhance temporal and spatial co-registration and improving the understanding of any relationship between these two parameters.  Our study aims to assess feasibility of studying these on an integrated PETMRI system.

Methods

7 patients with known aortic aneurysm were recruited in a vascular ultrasound screening follow up clinic.  During a single visit following 6 hours fasting, all patients underwent FDG injection and 60 minutes uptake period.  With quiet breathing, list mode PET acquisition and concurrent 4D PCMR was acquired using stacks of spiral acquisition, with ECG trace information for retrospective gating.  Images from the 4D PCMR and FDG PET were assessed qualitatively for image quality and visual matching.

Results

All 7 patients completed the study.  Overall image quality was adequate to good.  There is qualitatively a good concordance with impression of positive correlation between wall shear stress and inflammatory signal (see attached image).

Conclusion

We have demonstrated feasibility of combined assessment of mechanical and metabolic imaging parameters using an integrated PETMRI system.  Initial findings show there to be a broad concordance of wall shear stress and inflammatory signal in the abdominal aneurysm.

The ‘Wound Boot’: A Preliminary Assessment of a Novel Device for the Management of Leg Ulcers

Objective:

A preliminary assessment of a novel device, the ‘wound boot’, in the management of leg ulcers.

Procedures:

Eight subjects with ulcers wore the boot for 5–14 days. Ulcers were cleaned with saline only. No other dressings were applied. Questionnaires examined comfort and ease of use and asked for suggestions for modifications. Additionally, nurses examined ‘time taken to clean and dress ulcers’ in comparison with standard dressings. Although not a primary end-point, ulcer healing was noted.

Results:

For all, the boot was comfortable, easy to use and preferable to standard dressings. Ulcer-associated odour was eliminated entirely. A significant reduction was seen in the nursing time taken to clean and dress ulcers. Occasionally, excess exudate was problematic, with the boot's absorptive materials insufficient. In two cases, where the ‘boot’ was applied for 14 days, significant wound healing was seen.

Conclusions:

The prototype ‘boot’ helped significantly in leg ulcer management. Modifications based upon this assessment will allow a second prototype to be evaluated fully.

Effect of stockings on calf muscle oxygenation in patients with venous insufficiency

Background

The mechanism of action of stockings in symptom relief and treatment of venous insufficiency is still inadequately understood. Near-infrared spectroscopy (NIRS) provides continuous non-invasive monitoring of changes in tissue oxygen reserves and availability, by monitoring oxyhaemoglobin (HbO2), deoxyhaemoglobin (HbD) and cytochrome oxidase (CtO2). This study investigated the effect of stockings on calf muscle oxygenation during exercise using NIRS in patients with venous insufficiency.

Methods

Ten patients (mean(s.e.m.) age 56(5) years, seven women) with venous insufficiency participated in the study. Patients rested in a supine posture for 20 min. NIRS probes were attached to the calf at interoptodes spacing of 4 cm and initialized to zero. Calf oxygenation was continuously monitored during standing followed by a 5-min slow walk at 1·6 km h−1 with and without stockings chosen at random. A 30-min rest in the supine position was allowed between stockings. Pulse rate and peripheral oxygen saturation were monitored continuously by a pulse oximeter.

Results

Mean HbO2 concentration, HbD and mitochondrial oxygenation (CtO2) increased significantly with stockings during exercise.

Conclusion

Graduated compression stockings may achieve beneficial effects by improving calf muscle oxygenation during exercise in patients with venous insufficiency.

Decreased endothelin binding and receptor density in varicose veins

Background

The primary cause of venodilatation and reduced contractility in varicose veins is unclear. Endothelin (ET) 1 acts on smooth muscle cell ET A/ET B receptors to induce contraction and growth, and on endothelial cells to induce production of the vasorelaxant and growth inhibitors nitric oxide and prostacyclin. These factors may be involved in the aetiology of varicose veins. This study investigated ET-1 binding and ET A/ET B receptor density in varicose and non-varicose veins.

Methods

Proximal long sapheous vein (LSV) sections from nine patients undergoing surgery for varicose veins were compared with normal LSV from nine patients undergoing coronary artery bypass surgery. Slide-mounted sections were incubated in [125I]-radiolabelled ET-1 and ET A/ET B binding sites were identified using subtype-selective radioligands. Receptor density and distribution was quantified on autoradiographs by densitometry and binding was localized at the cellular level by nuclear emulsion.

Results

ET-1 binding and ET B receptor density decreased significantly in the varicose group. There was no significant difference in ET A receptor density.

Conclusion

Decreased ET-1 binding may contribute to venodilatation and poor contractility in varicose veins. This may be due to decreased tunica media ET B receptor density.

Endothelin receptors in the aetiology and pathophysiology of varicose veins

INTRODUCTION

varicose veins are tortuous and poorly contractile. Their aetiology remains unclear. Neovascularisation has been suggested as a possible explanation. Endothelins are mitogenic, promoting proliferation and migration of endothelial cells via endothelin-B receptors. We hypothesise that endothelial cells and endothelin receptor density and distribution may play a role in the development of varicosis.

METHODS

saphenous vein segments from nine patients with varicose veins were compared to six controls. Slide-mounted sections were incubated in radioactive labelled endothelin-1 and receptor subtype-selective ligands and binding sites assessed using autoradiography. Endothelin-1 and endothelial cells were identified by immunohistochemistry and CD31-positive staining cells counted.

RESULTS

radioactive labelled endothelin-1 and endothelin-B receptor binding was reduced in varicose compared to control veins (p=0.04). Endothelin-A receptor binding was diffuse, with no difference in density in both groups (p=0.58). Endothelin-B receptor binding was diffuse with superimposed clusters. Although the density of medial endothelin-B receptor binding was reduced in the varicose group, more clusters were identified in this group compared to controls (p=0.005). CD-31 staining identified these clusters as endothelial cells.

CONCLUSION

the reduced endothelin-1 binding and endothelin-B receptor density may be partially responsible for the reduced vasocontractility in varicose veins. We speculate that the increase in endothelin-B receptor binding CD31-positive endothelial cells in varicose veins may potentially stimulate mitogenesis and migration, leading to new vessel formation.

Graduated compression stockings in the prevention of venous thromboembolism

BACKGROUND

Surveys still show a wide variation in routine use of deep vein thrombosis (DVT) prophylaxis despite its established place in current patient management. This article reviews the mechanism of action, efficacy and complications of stockings in preventing DVT.

METHODS

Relevant publications indexed in Medline (1966-1998) and the Cochrane database were identified. Appropriate articles identified from the reference lists of the above searches were also selected and reviewed.

RESULTS AND CONCLUSION

Graduated compression stockings reduce the overall cross-sectional area of the limb, increase the linear velocity of venous flow, reduce venous wall distension and improve valvular function. Fifteen randomized controlled trials of graduated compression stockings alone were reviewed. Stockings reduced the relative risk of DVT by 64 per cent in general surgical patients and 57 per cent following total hip replacement. The effect of stockings was enhanced by combination with pharmacological agents such as heparin; the combination is recommended in patients at moderate or high risk of DVT. Knee-length stockings are as effective and should replace above-knee stockings. Complications are rare and avoidable.