Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.554047
Title: Minimally invasive treatment of venous insufficiency using endovenous laser ablation
Author: Carradice, Daniel
Awarding Body: University of Hull
Current Institution: University of Hull
Date of Award: 2011
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Abstract:
Background: Venous insufficiency is very common and causes significant quality of life (QoL) impairment. Conventional open surgery featuring junction ligation, stripping of the axial vein and phlebectomy is known to offer significant benefits over conservative management; resulting in improved QoL. Additionally this treatment has been shown to be highly cost-effective. Despite these advantages, surgery is associated with significant post-operative morbidity; in the form of pain and immobility, even in the absence of complications. Additionally, in the long term; high recurrence rates have marred these promising early results, eventually returning patients to their pre-operative state. Unsurprisingly recurrence is unpopular with patients and patient satisfaction has been observed to be disappointingly low. At the end of the 20th century, new minimally invasive endovenous interventions were developed. Rapidly gaining popularity; it was hoped that they could address some of the limitations of surgery. Following initial cases series; the endothermal technique of endovenous laser ablation (EVLA) appeared to have the highest technical efficacy with a good safety record. Objectives: Three studies were performed with the aim of perfecting the ablative procedure and evaluating it against the gold standard of conventional surgery. Study 1 was designed to establish the optimal management of saphenous tributaries and perforators following ablation of the saphenous axis. Study 2 was designed to directly compare the outcomes of EVLA with surgery to establish whether EVLA can match the effectiveness of surgery, whilst addressing its limitations. Study 3 was designed to explore the association between the magnitude of energy delivered during EVLA, procedural safety and periprocedural morbidity; in the context of evidence suggesting lower recanalisation rates following more aggressive use of laser energy. Methods: Studies 1 and 2 were randomised clinical trials. Participants had primary, symptomatic, unilateral venous insufficiency, with isolated saphenofemoral junction incompetence, leading to reflux into the great saphenous vein (GSV). Study 1 randomised 50 patients to EVLA alone (Control) or EVLA with concomitant ambulatory phlebectomies (EVLTAP). Study 2 randomised 280 patients equally into groups receiving either surgery or EVLA. Outcomes were: QoL, Venous Clinical Severity Score (VCSS), technical success, requirement for secondary procedures, pain scores, time taken to return to normal function, recurrent varicose veins on clinical examination, patterns of reflux on duplex ultrasound examination, and the effect of recurrence on quality of life. Assessments were at 1, 6, 12 and 52 weeks after the procedure. Study 3 used linear and logistic regression models to study the effect of energy delivery on outcome. The models controlled for age, gender, BMI, pre-operative QoL and vein dimension. The outcomes were QoL, complications, recovery time, pain scores and analgesia requirements. The sample size calculation established that 115 patients would be required to detect any significant relationship. Results: Study 1: EVLTAP took longer, but significantly decreased the requirement for subsequent interventions. There was no impairment in immediate post-procedural pain or QoL with EVLTAP. Median (IQR) Venous Clinical Severity Score (VCSS) at 3 months was lower (better) for EVLTAP than for Control (0 (0-1) versus 2 (0-2); P < 0.001), with lower (better) disease specific QoL (Aberdeen Varicose Vein Questionnaire (AVVQ) scores) at 6 weeks (7.9 (4.1-10.7) versus 13.5 (10.9-18.1); P < 0.001) and 3 months (2.0 (0.4-7.7) versus 9.6 (2.2-13.8); P = 0.015). At 1 year, there were no differences in VCSS or AVVQ scores. Study 2: Both groups had significant improvements in VCSS after treatment (P < 0.001), which resulted in improved disease-specific QoL (AVVQ, P < 0.001) and quality-adjusted life year (QALY) gain (P < 0.001). The pain and disability following surgery impaired normal function, with a significant decline in five of eight SF-36 domains (P < 0.001 to P = 0.029). Periprocedural QoL was relatively preserved following EVLA, leading to a significant difference between the two treatments in pain scores (P < 0.001), six of eight SF-36 domains (P = 0.004 to P = 0.049) and QALYs (P = 0.003). As a result, surgical patients took longer to return to work and normal activity (14 versus 3 days; P < 0.001). Complications were rare. Initial technical success was greater following EVLA: 99.3 versus 92.4% (P = 0.005). Surgical failures related mainly to an inability to strip the above-knee GSV. The clinical recurrence rate at 1 year was lower after EVLA: 4.0 versus 20.4% (P < 0.001). The number of patients needed to treat with EVLA rather than surgery to avoid one recurrence at 1 year was 6.3 (95 per cent confidence interval 4.0 to 12.5). 12 of 23 surgical recurrences were related to an incompetent below-knee GSV and ten to neovascularisation. Of five recurrences after EVLA, two were related to neoreflux in the groin tributaries and one to recanalisation. Clinical recurrence was associated with worse QoL (AVVQ scores) (P < 0.001). Study 3: 232 patients were included. The mean (range) age was 50 (18-83) years. 63% were women. The mean (range) energy delivery was 89.8 (44.5-158.4) Jcm-1. There was no significant effect on any outcome related to increasing energy delivery. Conclusions: Concomitant phlebectomy with EVLA prolonged the procedure, but reduced the need for secondary procedures and significantly improved quality of life and the severity of venous disease. This supports a recommendation that phlebectomy is performed routinely in conjunction with EVLA. EVLA was as effective as surgery for varicose veins, but importantly had lower periprocedural morbidity as evidenced by less negative impact on early post-intervention QoL and furthermore clinical recurrence rates were also significantly lower than observed following conventional surgery. This suggests that EVLA with phlebectomy is superior to conventional surgery in the management of primary superficial venous insufficiency. Study 3 clearly confirms that EVLA is a safe procedure and that for the range of energies studied, there was no evidence demonstrating an increase in complication rates or the periprocedural morbidity of EVLA. These findings support the adoption of EVLA and concomitant phlebectomy as the gold standard treatment for primary superficial venous insufficiency.
Supervisor: Chetter, Ian. Sponsor: Diomed (Firm) (Sponsor) ; Angiodynamics (Firm) (Sponsor)
Qualification Name: Thesis (M.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.554047  DOI: Not available
Keywords: Medicine
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