Abdominal collateral veins as an unconventional access site for hemodialysis after primary access failure

Introduction: Vascular access dysfunction and the depletion of access pathways are complications associated with morbidity and mortality in dialysis patients. As described in the literature, catheter insertion through small collateral veins or recanalized cervical and thoracic veins is an attractive option. Case Description: This article reports a case in which a collateral vein in the abdominal region was used as an access for hemodialysis. Conclusion: After multiple attempts with fistulas and catheters, the left abdominal wall collateral network proved to be a successful access site. Using unconventional veins can be an alternative in these patients.

A Rare Cause of Persistent Blood Loss after Continuous Ambulatory Peritoneal Dialysis Catheter Placement

The laparoscopic placement of a continuous ambulatory peritoneal dialysis (CAPD) catheter is a widely used method in patients with end stage renal disease (ESRD). The potential complications of this procedure include perforation of intra-abdominal organs, surgical site infection, peritonitis, catheter migration, catheter blockage, port site herniation, and bleeding. In most cases, bleeding is considered to be an early-onset complication because it mostly occurs within the first seven days after surgery. We report a case of a 68-year-old female patient with a previous history of diabetes mellitus, myelodysplastic syndrome, extensive collateral varices, anaemia, and ESRD due to obstructive uropathy caused by retroperitoneal fibrosis, who presented with persistent blood loss after the laparoscopic placement of a CAPD catheter. Duplex ultrasonography showed that the CAPD catheter was transfixing a superficial epigastric varicose vein, a collateral vein, due to the occlusion of the left external iliac vein. Persistent blood loss after inserting a CAPD catheter without previous imaging of abdominal wall vessels is an indication for further diagnostics.

Endovascular salvage of non-maturing autogenous arteriovenous fistulas by using angioplasty and competitive vein embolization

Introduction: The aim of this study is to evaluate the maturation and patency rates after endovascular treatment of non-maturing arteriovenous fistulas with percutaneous transluminal angioplasty, embolization of competitive veins, or a combination of both in a series of consecutive patients. Material and methods: Retrospective evaluation of patients with non-matured arteriovenous fistulas treated in our hospital was performed. Fistulography and ultrasonography was performed in all patients to evaluate the presence of stenosis and competitive veins. Significant stenoses (> 50%) were treated with balloon angioplasty and competitive veins (accessory and collateral veins) with coil embolization. Results: A total of 78 fistulas were treated. Angioplasty and coil embolization were performed in 73 and 51 patients, respectively. No major complications occurred. In 65 out of 78 arteriovenous fistulas (83%), successful cannulation with two needles was possible after endovascular treatment. Sixty-three arteriovenous fistulas (81%) were used successfully for at least 3 months. Accessory veins were the only lesion present in 14% of the arteriovenous fistulas; coil embolization of these accessory veins resulted in 100% successful maturation. The estimated 3, 6, and 12 months postintervention assisted primary patency rates were, respectively, 73%, 55%, and 45%. The estimated 3, 6, and 12 months postintervention secondary patency rates were, respectively, 81%, 78%, and 73%. Conclusion and discussion: Angioplasty and coil embolization are successful and safe procedures that can convert a non-mature fistula into a mature one in more than 80% of patients. Accessory vein embolization may be more important than collateral vein embolization in the presence of stenosis.

Endovascular Options for Nonmaturing Fistulas due to Collateral Flow

The “failing to mature” arteriovenous fistula (AVF) is a surgically created AVF that fails to properly dilate to become usable for hemodialysis within 8–12 weeks after its creation. Difficult cannulation and inadequate AVF flow are the clinical manifestations of the “failing to mature” fistula. Early thrombosis of a newly created fistula is a possible cause of a “failing to mature” AVF. Early AVF thrombosis has similar underlying derangements as the immature fistula and both can be salvaged using endovascular techniques, including embolization of collateral veins via coils or endovascular plugs. Complications of collateral vein embolization include local hematoma formation, inadvertent coiling of the outflow vein, pain, erythema at the site of collateral vein embolization, migration of the coils, and, rarely, skin erosion at the site of the embolized superficial collateral vein. Patients need to be followed up with a fistulagram within 1 month of embolization.

Direct versus indirect revascularization in the treatment of moyamoya disease

OBJECTIVEFor patients with moyamoya disease (MMD), surgical intervention is usually required because of progressive occlusion of the internal carotid artery. The indirect bypass method has been widely accepted as the treatment of choice in pediatric patients. However, in adult patients with MMD, the most effective treatment method remains a matter of debate. Here, the authors compared the clinical outcomes from MMD patients treated with either extracranial-intracranial arterial bypass (EIAB; 43 hemispheres) or modified encephaloduroarteriosynangiosis (mEDAS; 75 hemispheres) to investigate whether mEDAS is an effective surgical method for treating adults with symptomatic MMD.METHODSA comparative analysis was performed in patients treated using either mEDAS or EIAB. Collateral grading, collateral vein counting, and symptom analysis were used to assess the outcome of surgery.RESULTSSeventy-seven percent (58/75) of mEDAS cases and 83.7% (36/43) of EIAB cases in the analysis experienced improvement in their symptoms after surgery. Furthermore, patients in 98.7% (74/75) of mEDAS cases and those in 95.3% (41/43) of EIAB cases exhibited improved collateral grades. Increases in regions of perfusion were seen after both procedures.CONCLUSIONSModified EDAS and EIAB both result in positive outcomes for symptomatic adults with MMD. However, when considering the benefit of both surgeries, the authors propose mEDAS, a simpler and less strenuous surgery with a lower risk of complications, as a sufficient and safe treatment option for symptomatic adults with MMD.

Venous stent patency may be affected by collateral vein lumen size

Purpose Deep venous thrombosis causes blood flow deviation. It is hypothesized that with stent placement, developed collateral veins become redundant. This article evaluates the relation between the surface area of the collaterals and stent patency. Methods The azygos and hemiazygos veins were identified and the largest surface area was measured at thoracic level. Patency rates of stented tracts were evaluated and related to collateral vein lumen size. Results The vena cava occlusion and the azygos and hemiazygos vein surface area measurements were positive and statistically significant related (OR 1.01, 95% CI 1.003−1.019, p = 0.004) respectively (and OR 1.007, 95% CI 1.001−1.013, p = 0.004). An azygos surface area measurement of 23 (p<0.001) and hemiazygos surface area measurement of 40 (p = 0.008) was shown as cut-off point related to higher occlusion rates. Conclusions The surface area of major venous collateral pathways seems to be related to stent occlusion in deep venous interventions.

Suprapubic varicose vein formation during pregnancy following pre-pregnancy pelvic vein embolisation with coils, without any residual pelvic venous reflux or obstruction

Suprapubic varicose veins are usually indicative of unilateral iliac vein occlusion and venous collateralisation. We report two cases of suprapubic varicose veins following pelvic vein embolisation and subsequent pregnancy; both presented without residual pelvic venous reflux or pelvic venous obstruction. In both cases, there was no significant flow in the suprapubic veins indicating that they were not acting as a collateral post-pregnancy. One patient had this venous abnormality treated successfully with TRansluminal Occlusion of Perforators, followed by foam sclerotherapy to the main part of the suprapubic vein. This patient has since completed the reminder of her lower limb varicose vein treatment. We suggest that pregnancy may have caused prolonged intermittent compression of the left common iliac vein, and that this, together with the physiological impact of previous embolisation procedures, obstructed venous drainage from the left leg resulting in collateral vein formation within the 9-month gestation period.