Primary varicose veins are due to either predisposed weakness in the mesenchymal tissue or due to valve incompetence that is presumed idiopathic or potentiated by physical and lifestyle factors of the patients. Owing to their impact on the affected populations different management modalities have been proposed for intervention in primary varicose veins either surgical or less invasive techniques that proved to be of the upper hand in terms of efficacy, less complications, less hospital stay and most importantly with a reported success rate of approximately 90%, in previous studies in the literature [3–7] and declined recurrence rates [ 8, 9, 10] long-term durability of a procedure is the main factor of choosing one intervention over the other and the most important key outcome to assess this durability is recurrence [11, 12]. The great saphenous receives blood from three main vessels which are the superficial epigastric, superficial circumflex and superficial external pudendal which are normally ligated during surgical interventions for primary varicosities however in EVLA management is targeted only for catheter ablation of the great saphenous ,many studies have denoted a hydrostatic backflow in these draining veins following the ablation of the great saphenous vein in EVLA leading to their enlargement and incompetence .though this drawback of EVLA in comparison to surgery could increase incidence of recurrence. total risk of recurrence after EVLA compared to surgery is markedly lower [13–15].
Recurrence incidence increases with the length of time after the procedure [16–18]. Recurrence after EVLA mostly occur in several tributaries veins of GSV below the saphenofemoral junction (SFJ), one of which is the anterior accessory vein (AASV) or in the perforators [8, 21].
Possible explanations for new AASV insufficiency are that once the GSV is ablated, flow is then directed to the AASV either with its inherited defects in the vein wall or valves causing insufficiency [19, 20] or causing recanalization of the previously treated GSV [14].
Moreover, a true relationship between recurrent GSV insufficiency and incompetent postoperative calf perforators was documented in the REVATA study and concluded that ablation should begin at the mid-calf level below these perforators to reduce the chance of future new insufficiency in untreated segments in addition to ablation of calf perforators [19].This reinforces our findings that preoperative patent AASV and postoperative residual perforators could play a major role in the prediction of recurrence through new retrograde flow in AASV after GSV ablation and enlargement of calf and thigh perforators "arterialization" [19] mainly which enhances GSV recanalization rates and new GSV reflux [22].
Medium-term follow-up studies suggested equivalent recurrence rates and quality of life at 2 to 5 years after treatment between different management modalities [19], Neovascularization has been reported more frequently following surgery [23] ;on the other hand, recanalization was reported more with EVLA demonstrating that recanalization of the GSV occurred in 29% of limbs [20]. Determinants of this recurrence after EVLA have not been studied in previous literature. In Our study, Effects of variable determinants on the recurrence rates and patterns after EVLA during midterm (2-year) follow-up. Age, Gender, BMI, pre-operative dilated GSV (≥ 5.5 mm), preoperative AASV and postoperative remaining perforators were the major determinants studied in each patient and the patients were standardized to the same device (1470 nm diode laser, 15 W) and used a standard LEED (linear endovenous energy density) for ablation. VCSS and CEAP classification were used for perioperative clinical assessment.
Although no evidence was found in the literature to explain the male predominance in the risk of recanalization, it could be hypothesized that the vein wall of males is thicker than the vein wall of females. Also although pre-operative dilated GSV (≥ 5.5 mm) was seen 88.6% of recurrent patients compared to 66.7% of non-recurrent patients in our study, it was found to be statistically insignificant, and it became a controversial issue to treat patients with very large GSV diameter<) 12 mm) using EVLA, However GSV diameter may predict the risk of early recanalization after the EVLA especially if the diameter < 10 mm [24–27].As we used standard LEED for above-knee GSV segment (100 j/cm) and for the below-knee segment (80 j/cm) and one of the two patients with preoperative GSV diameter < 8 mm developed recurrence in our study, we suggest that large GSV diameter could play a role in recanalization rates after EVLA although it was not confirmed in our study.
Upon assessment of the BMI of patients in our study, it was found to have fair to good predictive value for recurrence after EVLA with cutoff < 30.5 kg/m2. In the comparison of this statistically significant finding in our study to previous studies: A retrospective cohort study by Merchant and Pichot documented an association between high body mass index (BMI) and recurrence after five years. The mechanism by which a high BMI results in anatomical failure remains unclear [28] while it can be due to increased femoral venous pressure [29] or increase in intraabdominal pressure [30], On the other hand, Theivacumar et al. reported no influence of BMI on early truncal occlusion rates after laser ablation [23].
The presence of AASV and postoperative residual thigh and calf perforators in addition to BMI < 30 kg/m2 are major determinants of recurrence after EVLA and are documented in most previous studies. The gender and preoperative GSV diameter are still controversial and need to be addressed in further studies, also Optimum prevention of recurrence in a previously ablated GSV is tailored to the identification of many potential risk factors: higher VCSS score, GSV diameter, saphenofemoral junction reflux, length of the ablated vein, type of device & male sex have all been reported to increase risk of Recurrence. However, most studies of endovenous ablations neither report potential risk factors for reflux recurrence nor identify significant differences in recurrence rates of both endovenous and surgical ablations [25, 26]. The question of whether these specific determinants impact a certain recurrence pattern should be assessed and further studies should be undertaken either to study determinants of recurrence and their potential impact on rates and patterns of recurrence to formulate recurrence prevention guidelines by addressing those determinants.