External Iliac Vein Research Articles

External iliac vein compression and lower-extremity swelling caused by an iliopectineal ganglion: a case report

BackgroundA hip joint ganglion is a rare cause of lower-extremity swelling.Case presentationWe report a case of a Japanese patient with ganglion of the hip with compression of the external iliac/femoral vein that produced signs and symptoms mimicking those of deep vein thrombosis.ConclusionsNeedle aspiration of the ganglion was performed, and swelling of the lower extremity promptly decreased. At 7.5 years after aspiration, there was no recurrence of swelling of the leg. Although the recurrence rate for ganglions after needle aspiration is high, it is worthwhile trying aspiration first.

Predictors of symptomatic lymphocele after kidney transplantation

PurposeThe development of a symptomatic lymphocele (SL) is a frequent postoperative surgical complication after kidney transplantation. It may lead to pain and discomfort and cause transplant malfunction or even secondary graft loss. A large cohort of renal recipients was investigated to identify the possible risk factors for SL.MethodsAll renal transplant patients of a single centre were retrospectively analysed for SL between January 2010 and December 2017. The SL group was compared to a control group from the same cohort.Results45 out of 1003 transplanted patients developed an SL (incidence 4.5%), on average 50 days after kidney transplantation. SLs developed more in older patients, in those with a PD catheter and in ADKDP as primary diagnosis. Surgical predictors for SLs were venous anastomosis on the external iliac vein, concomitant PD catheter removal, perfusion defects, shorter operating time, splint > 7 days, double J stenting, discharge with drain, low initial drain production and ureteral obstruction. Opening of the peritoneum, re-operation for postoperative bleeding and previous nephrectomy seem protective for developing SL.ConclusionWe found multiple heterogeneous predictors for SL with a common denominator related to surgical management of the retroperitoneal space, peritoneum and the ureter. Future prospective studies are necessary to evaluate the influence of these variables on the development of SL.

Corona Mortis: the Abnormal Obturator Vessels in Filipino Cadavers

Objectives. This is a descriptive study to determine the origin of abnormal obturator arteries, the drainage of abnormal obturator veins, and if any anastomoses exist between these abnormal vessels in Filipino cadavers.
 Methods. A total of 54 cadaver halves, 50 dissected by UP medical students and 4 by UP Dentistry students were included in this survey.
 Results. Results showed the abnormal obturator arteries arising from the inferior epigastric arteries in 7 halves (12.96%) and the abnormal communicating veins draining into the inferior epigastric or external iliac veins in 16 (29.62%). There were also arterial anastomoses in 5 (9.25%) with the inferior epigastric artery, and venous anastomoses in 16 (29.62%) with the inferior epigastric or external iliac veins. Bilateral abnormalities were noted in a total 6 cadavers, 3 with both arterial and venous, and the remaining 3 with only venous anastomoses.
 Conclusion. It is important to be aware of the presence of these abnormalities that if found during surgery, must first be ligated to avoid intraoperative bleeding complications.

DANTE-SPACE: a new technical tool for DVT on 1.5T MRI

The aim of the study was to compare CE-MRV with DANTE-SPACE on a 1.5T MRI system for the diagnosis of DVT. The patients were diagnosed with deep venous thrombosis of the lower extremities based on swelling, pain, and superficial varicose veins of the lower extremities. MRI examination confirmed the diagnosis. DANTE-SPACE images were obtained before the conventional contrast-enhanced MRV, which uses gadolinium. The scanning field started from the end of the inferior vena cava to the end of the ankle, divided into five observation segments, namely, the common iliac vein, external iliac vein, femoral vein, popliteal vein, and calf vein. The DANTE-SPACE and CE-MRV results were used for a consistency analysis. For the DANTE-SPACE and CE-MRV images, the signal intensity ratios of the thrombus/cavity and thrombus/muscle were calculated, and the ratio difference was compared using the paired t test. Twenty-six patients completed the examination; one of the patients underwent a right lower limb amputation, yielding a total of 255 lower limb vascular segments. The analysis of the DANTE-SPACE images showed that there were 14 iliac vein thromboses, 18 external iliac vein thromboses, 23 femoral vein thrombi, 21 popliteal vein thromboses, and 18 calf vein thromboses; these findings were consistent with the diagnostic results of CE-MRV. The ratio of the thrombus/cavity signal intensity measured in the DANTE-SPACE and CE-MRV images were as follows: 20.51 ± 12.96 vs. 0.51 ± 0.46; P < 0.05, n = 51; the difference was statistically significant. The ratio of the thrombus/muscle signal intensity measured on the DANTE-SPACE and CE-MRV images were as follows: 1.74 ± 0.57 vs. 0.99 ± 0.53; P < 0.05, n = 51; the difference was statistically significant. Compared with CE-MRV, DANTE-SPACE showed no significant difference in the ability to detect deep venous thrombosis of the lower extremities. DANTE-SPACE did not use contrast-enhancing agents and showed no evidence of inflammatory enhancement, and the display effect of small diameter veins was slightly poor. However, deep venous thrombosis of the lower extremities presents different levels of high signal in the DANTE-SPACE images, making it easy to identify and diagnose. It can also indicate the different components and age of the thrombus and help with the selection of a more accurate clinical treatment plan. MRI DANTE-SPACE is the preferred imaging modality for patients with deep venous thrombosis who are unable or unwilling to use gadolinium contrast agents.

Tigers in the Sidewall: Surgical Approaches to Excision of Lateral Deep Infiltrating Endometriosis

ObjectiveTo describe the surgical approaches and excisional techniques used in an extreme case of deep infiltrating endometriosis (DIE) affecting the lateral pelvic side wall. DesignA technical video showing the excision of advanced lateral DIE. SettingAn academic tertiary care hospital. InterventionsA 32-year-old woman, gravida 2, para 1, presented for definitive surgical management of endometriosis-associated pelvic pain. Intraoperative findings revealed severe retroperitoneal fibrosis tethering the external iliac vein, internal iliac artery, obturator nerve, medial umbilical ligament, and ureter. The patient underwent laparoscopic management of the DIE involving the lateral pelvic side wall. We demonstrate the surgical methods and tools required to overcome a unique endometriotic nodule that would not allow for traditional lysis of adhesions from the pelvic side wall. Instead, we used a nontraditional surgical approach by tunneling under the external iliac vascular to tackle the dissection from a lateral to medial direction to free the obturator nerve and internal iliac artery from the ureter and endometriotic nodule. ConclusionExtreme cases of DIE involving the pelvic side wall require surgical finesse when normal planes of dissection are obliterated. Knowledge of retroperitoneal anatomy is critical to overcome unexpected lateral pelvic side wall endometriosis because the disease is rarely confined to the surface. Innovative surgical thinking complemented by an array of surgical tools will ultimately allow the surgeon to master these difficult endometriotic resections.

Laterally extended endopelvic resection with external iliac vessels resection and crossover ileofemoral bypass

Involvement of major pelvic vessels is one of the traditional contraindications of surgical treatment for recurrent gynecologic cancers. In our experience, ligation of the external iliac vein is also feasible...

Clinical characteristics and risk factors of proximal deep venous thrombosis in patients with fractures

Objective To investigate the clinical characteristics and risk factors of perioperative deep venous thrombosis(DVT) in fracture patients. Methods A retrospective case control study was conducted to analyze the clinical data of 147 patients with DVT diagnosed by color Doppler ultrasound or lower extremity deep venography from July 2015 to November 2017 in Honghui Hospital Affiliated to Xi'an Jiaotong University College of Medicine. The patients were divided into proximal thrombosis group (including the popliteal vein) and distal thrombosis group according to the involvement site with the popliteal vein as reference. The proximal thrombosis group (56 patients) included 31 males and 25 females, aged 38-89 years, with an average age of 67.8 years. There were three patients with pelvic and acetabular fractures, 39 with hip fractures, 10 with femoral shaft fractures, three with periarticular fractures, and one with tibia and fibula fracture. According to the site of involvement, four patients had proximal vein thrombosis, and the other 52 patients had proximal combined with distal thrombosis. There were 44 patients with left thrombosis and 12 with right thrombosis. Thrombosis at femoral vein and above was found in 20 patients (7 with external iliac vein thrombosis), and thrombosis at popliteal vein was found in 36 patients. The distal thrombosis group (91 patients) consisted of 51 males and 40 females, aged 21-92 years, with an average of 63.6 years. There were 12 patients with pelvic and acetabular fractures, 39 with hip fractures, four with femoral shaft fractures, 16 with fractures surrounding knee joint, 12 with tibia and fibula fractures, and eight with ankle joint fractures. There were 43 patients with left thrombosis and 48 with right thrombosis. The gender, age, fracture location, time from injury to operation, operation time, blood transfusion rate, thrombus side, D-dimer level before and after operation, and internal medical diseases were compared between the two groups. The risk factors with statistical significance were screened for multivariate Logistic regression analysis. Results In proximal thrombosis group, 70% (39/56) had hip fracture and 18% (10/56) had femoral shaft fracture, while 43% (39/91) had hip fracture and 4% (4/91) had femoral shaft fracture in distal thrombosis group (P 0.05). Logistic regression analysis showed that hip fracture and femoral shaft fracture, left lower limb, blood transfusion, high D-dimer level before and after operation were risk factors for proximal thrombosis. Conclusions Proximal venous thrombosis is often combined with distal venous thrombosis. Hip fracture, femoral shaft fracture, left lower limb, blood transfusion, preoperative and postoperative high D-dimer levels have significant effects on proximal thrombosis. Key words: Venous thrombosis; Fractures, bone; Risk factors

Anatomical Variations of Iliac Vein Tributaries and Their Clinical Implications During Complex Pelvic Surgeries.

During high sacrectomies and lateral pelvic compartment exenterations, isolating the external and internal iliac veins within the presacral area is crucial to avoid inadvertent injury and severe hemorrhage. Anatomical variations of external iliac vein tributaries have not been previously described, whereas multiple classifications of internal iliac vein tributaries exist. We sought to clarify the iliac venous system anatomy using soft-embalmed cadavers. This is a descriptive study. This study was conducted in Chulalongkorn University, Thailand. We examined 40 iliac venous systems from 20 human cadavers (10 males, 10 females). Blue resin dye infused into the inferior vena cava highlighted the iliac venous system, which was meticulously dissected and traced to their draining organs. Iliac vein tributaries and their valvular system were documented and analyzed. The external iliac vein classically receives 2 tributaries (inferior epigastric and deep circumflex iliac) near the inguinal ligament. However, external iliac vein tributaries in the presacral area were found in 20 venous systems among 15 cadavers (75%). The mean diameter of each tributary was 4.0 ± 0.35 mm, with 72% arising laterally. We propose a simplified classification for internal iliac vein variations: pattern 1 in 12 cadavers (60%) where a single internal iliac vein joins a single external iliac vein to drain into the common iliac vein; pattern 2 in 7 cadavers (35%) where the internal iliac vein is duplicated; and pattern 3 in 1 cadaver (5%) where bilateral internal iliac veins drain into a common trunk before joining the common iliac vein bifurcation. This study is limited by the number of cadavers included. A comprehensive understanding of previously unreported highly prevalent external iliac vein tributaries in the presacral region is vital during complex pelvic surgery. A simplified classification of internal iliac vein variations is proposed. See Video Abstract at http://links.lww.com/DCR/A900.

Effect of venous access site on postintervention stent thrombosis for nonthrombotic iliac vein stenting

ObjectivePrior literature suggests that routine femoral vein (FV) puncture is necessary for interrogation of the iliac veins for stenosis to avoid missing common femoral vein (CFV) lesions. However, this can be technically challenging and poses small but increased risks. The purpose of this study was to compare the incidence of stent thrombosis after iliac vein stenting in the treatment of nonthrombotic iliac vein lesions with use of two discrete venous access sites—the CFV and FV. MethodsDuring 4 years, we performed 1605 lower extremity venography studies with intravascular ultrasound (IVUS). There were 372 men and 689 women with an average age of 66 years (range, 21-99 years; standard deviation [SD], ± 14.3 years). After IVUS interrogation, 1513 procedures resulted in venous stenting; 964 patients received stent placement in the common iliac vein, 513 in the external iliac vein, 24 involving the CFV, and 12 involving the FV. The venous puncture site, accessed by ultrasound guidance, varied between the CFV and FV per the surgeon's choice and was documented on the basis of the most distal vein area measured by IVUS during the procedure. Patients were followed up with iliocaval and lower extremity duplex ultrasound within 2 weeks and every 3 months thereafter for the first year. ResultsThere were 994 patients who received CFV puncture and 611 patients who received FV puncture. In 39 (4.2%) patients receiving CFV punctures with subsequent stent placement, any stent thrombosis developed within 30 days of the intervention; 27 (69.2%) were complete thromboses. In 21 (3.6%) patients who received FV punctures with subsequent stent placement, any stent thrombosis developed within 30 days of intervention; 17 (81.0%) were complete thromboses. There was no significant difference (P = .57) in ≤30-day thromboses between the CFV and FV cohorts. Any in-stent thrombosis developed >30 days after intervention in 18 patients, 11 in limbs that received CFV puncture and 7 with FV puncture (P = .98). Complete stent occlusion occurred in three cases of CFV puncture. No FV punctures led to >30-day complete stent thromboses. The median time to diagnosis of >30-day thrombosis was 11.1 months (range, 2.6-31.9 months; SD, ± 12.86 months). Median follow-up was 20 months (SD, ± 19.18 months). ConclusionsThere was no significant difference between in-stent thrombosis rate and location of initial venous puncture in the setting of outpatient IVUS-guided venography. Both the CFV and FV can be safely used as puncture sites for lower extremity venography.

Is it necessary to dilate stents in management of nonthrombotic iliac vein lesions?

ObjectiveIliac vein stenting is an evolving treatment option for chronic venous insufficiency and management of nonthrombotic iliac vein lesions (NIVLs). Currently described protocols recommend deployed stents to be dilated with balloon venoplasty before completion of the procedure, based on previous literature established from management of arterial lesions. The objective of the study was to investigate the role of balloon venoplasty after stent deployment in the management of NIVLs. MethodsDuring the course of 6 months, 71 balloon venoplasties with stenting of iliac veins (34 right and 37 left limbs) were performed. Intraoperatively, we used intravascular ultrasound to measure and to record area of iliofemoral veins. The measurement of stenosis was compared with adjacent nonstenotic iliofemoral veins. If >50% cross-sectional area or diameter reduction was found, it was treated with an appropriate balloon size (range, 10 × 40 mm to 16 × 60 mm) and Wallstent (Boston Scientific, Natick, Mass; 12-24 mm in diameter by 40-90 in mm length). All stents were dilated with a balloon after deployment. Intravascular ultrasound was used to measure the preoperative area of stenotic lesion, area of lesion after stenting, and area after balloon dilation of the stent. ResultsThe mean age of the patients was 65.34 years (range, 36-99 years; standard deviation [SD], ±13.52 years), with 27 female and 20 male patients. The location of the targeted stenosis was the common iliac vein (31), external iliac vein (36), and common femoral vein (4). The mean area of the stenotic lesion was 99.06 mm2 (range, 28-318 mm2; SD, ±45.87 mm2). The mean area after stenting was 151.51 mm2 (range, 28-303 mm2; SD, ±55.82 mm2). The mean area after dilation of the stent was 162.72 mm2 (range, 86-367 mm2; SD, ±51.94 mm2; P = .22). No statistically significant correlation was found between difference in areas and age of the patient, clinical class (C2-C6), sex, lesion, laterality, and location of targeted lesion. One patient developed an intraluminal partial thrombus within 30 days of intervention. ConclusionsOur preliminary data show no significant clinical or technical benefit with use of balloon venoplasty to dilate stents after deployment in NIVLs. Postdilation should thus be limited to only those with suboptimal self-expansion of stent after initial deployment on fluoroscopic imaging.

A comparison between intravascular ultrasound and venography in identifying key parameters essential for iliac vein stenting

ObjectiveDeep venous stenting has become the primary treatment option for obstructive venous disease. Precise identification and quantification of the disease as well as localization of optimal landing zones are key elements to success. Compared with venography (anteroposterior projection), intravascular ultrasound (IVUS) seems to be more sensitive in determining those parameters. This study was a blinded comparison of the relative accuracy of venography compared with IVUS in determining key parameters essential for iliac vein stenting. MethodsBetween October 2013 and November 2015, there were 155 limbs (152 patients) that underwent an endovascular intervention for chronic iliofemoral vein stenosis. Venography and IVUS data were reviewed by vascular surgeons and radiologists, respectively, each blinded to the other to identify location and severity of maximal stenosis, location of iliac-caval confluence, and optimal distal landing zone. Data from venography were compared with data from IVUS. Maximal stenosis was defined as the most severe stenosis found among the four segments—common iliac vein, external iliac vein, common femoral vein, and infrarenal vena cava. IVUS was the “gold standard” for comparisons. ResultsVenography failed to identify lesion existence in 19% of limbs. The median maximal area stenosis was significantly higher with IVUS than with venography (69% vs 52%; P < .0001). Furthermore, venographic correlation with IVUS for the anatomic location of maximal stenosis was present in only 32% of the limbs; venography missed the location of maximal stenosis in more than two-thirds of limbs. The iliac-caval confluence location on venography correlated with IVUS findings in only 15% of patients. In 74%, it was located higher with IVUS than with venography. The mean difference was one vertebral body. Agreement between venography and IVUS on location of the distal landing zone was only 26%. The distal landing zone defined with IVUS was lower than with venography in 64% of limbs. ConclusionsCompared with IVUS, venography substantially and significantly misses stenotic lesions—their location and severity; venography also misidentifies the location of the iliac-caval confluence and the distal landing zone in the majority of limbs. Those differences between IVUS and venography suggest that IVUS is the better diagnostic and procedural tool in iliac-caval stenting.

Assessing Therapeutic Angiogenesis in a Murine Model of Hindlimb Ischemia.

Critical limb ischemia (CLI) is a serious condition that entails a high risk of lower limb amputation. Despite revascularization being the gold-standard therapy, a considerable number of CLI patients are not suited for either surgical or endovascular revascularization. Angiogenic therapies are emerging as an option for these patients but are currently still under investigation. Before application in humans, those therapies must be tested in animal models and its mechanisms must be clearly understood. An animal model of hindlimb ischemia (HLI) has been developed by the ligation and excision of the distal external iliac and femoral arteries and veins in mice. A comprehensive panel of tests was assembled to assess the effects of ischemia and putative angiogenic therapies at functional, histologic and molecular levels. Laser Doppler was used for the flow measurement and functional assessment of perfusion. Tissue response was evaluated by the analysis of capillary density after staining with the anti-CD31 antibody on histological sections of gastrocnemius muscle and by measurement of collateral vessel density after diaphonization. Expression of angiogenic genes was quantified by RT-PCR targeting selected angiogenic factors exclusively in endothelial cells (ECs) after laser capture microdissection from mice gastrocnemius muscles. These methods were sensitive in identifying differences between ischemic and non-ischemic limbs and between treated and non-treated limbs. This protocol provides a reproducible model of CLI and a framework for testing angiogenic therapies.

EARLY PHASE POSTMORTEM REDISTRIBUTION OF LIDOCAINE AND MIDAZOLAM IN ADULT ALBINO RATS

Background: Postmortem redistribution (PMR) is the changes that occur in drugconcentrations after death. Lidocaine is the most popular local anesthetic used worldwideand midazolam is a widely used pre-anesthetic anxiolytic and sedative. Aim of theWork: This work was performed to study potential early phase postmortemredistribution of lidocaine and midazolam, as well as, the influence of storagetemperature on it in adult albino rats. This was done by measuring their concentrations inblood (cardiac blood and external iliac vein blood) and tissues (heart, lungs and liver).Calculation of cardiac blood to peripheral blood ratio (C/P) and Liver to peripheral bloodratio (L/P) was performed. Materials and Methods: This study was carried out on 36adult male albino rats which divided into two main groups (18 rats each). Group I(Lidocaine): Rats received a single SC injection of 2% lidocaine HCL (67 mg/kg), andsacrificed 30 minutes later. This group was subdivided into three equal groups; AMcontrol (L-AM), 15 minutes PM at 4oC (L-PM4) and 15 minutes PM at 21oC (L-PM21).Group II (Midazolam): Rats received single IV injection of midazolam (75 mg/kg), andsacrificed 30 minutes later. This group was subdivided into three equal groups; AMcontrol (M-AM), 15 minutes PM at 4oC (M-PM4), 15 minutes PM at 21oC (M-PM21).Results: There were significant changes in lidocaine and midazolam concentrations inboth tissues and blood samples as compared to those of corresponding AM controlgroups. Markers of PMR revealed early phase PMR of lidocaine by L/P ratios > 20 at 21oC. Storage temperature at 4oC arrested lidocaine PMR as recorded by both C/P ratios <1 and L/P ratios < 5. Midazolam was prone to postmortem degradation that interferedwith PMR assessment. Midazolam revealed minimal early phase postmortemredistribution as demonstrated by C/P ratios just above 1 at 4 oC. L/P ratio was a morereliable marker for PMR than C/P ratio. Conclusion: Lidocaine was highly liable toundergo early phase PMR as demonstrated by L/P ratios above 20 at 21 oC. However,storage at 4oC retarded lidocaine PMR. Midazolam was subjected to postmortemdegradation and had minimal early phase PMR as demonstrated by C/P ratios just above1 at 4 oC. Recommendation: it is recommended to increase forensic toxicologists'awareness about PMR of lidocaine and midazolam, and their influence on theinterpretation of PM toxicological analysis.

SS16. A Novel Technique for Iliocaval Extravascular Reconstruction and Associated Outcomes in Patients With Inferior Vena Cava Agenesis

Congenital absence of the inferior vena cava is a rare deep venous malformation associated with venous stasis ulceration. Endovascular recanalization is limited as patients lack normal anatomic pathways required for endovascular repair. The purpose of this study was to report outcomes of a novel retroperitoneal technique for iliocaval extravascular reconstruction (TIER) using re-entry techniques for the treatment of C5 to C6 disease in patients with iliocaval agenesis. A prospectively maintained single-institution database was used to observe patients who underwent TIER for management of C5 to C6 venous disease. Reconstruction was performed by sharply exiting the deep venous system and entering the retroperitoneum at or above the renal confluence and the bilateral external iliac veins. Cone beam computed tomography was used to exclude potential injury to adjacent structures during retroperitoneal transcatheter dissection. Reconstruction was performed using self-expanding Elgiloy stents. The Villalta clinical scoring system for post-thrombotic syndrome was used to assess symptomatic improvement preoperatively and postoperatively. Postoperatively, patients with C6 venous disease underwent continued compression therapy and were monitored for wound healing. Twelve patients underwent TIER for complete absence of the inferior vena cava resulting in C5 to C6 disease during the study period (Fig 1). Technical success was 100%, with primary patency achieved in all patients (Fig 2). There were no significant intraoperative complications, and the 30-day mortality was 0%. Mean contrast agent volume used was 87 mL, mean fluoroscopy time was 143 minutes, and mean reference air kerma was 6239 mGy. A minimum of six stents were used in all cases. At follow-up intervals of 1, 3, and 6 months, primary patency was 100%. Symptomatic and sustained improvement was seen in all patients with an average decrease in Villalta score of 13. Nine patients had C6 venous disease with ulcers on 15 limbs due to the presence of bilateral disease. Thirteen limbs had complete ulcer resolution during the follow-up period. The remaining limbs demonstrated >75% ulceration size reduction. Iliocaval extravascular reconstruction using novel re-entry techniques appears to be a safe and effective endovascular approach for the treatment of symptomatic congenital absence of the inferior vena cava. The TIER procedure can be performed with excellent patency, minimal morbidity, improved Villalta scores, and improved healing.Fig 2View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Arteriovenous Fistula Is a Rare but Significant Finding After Endovenous Thermal Ablation

Endovenous thermal ablation (EVTA) has become the mainstay of treatment for symptomatic varicose veins in the setting of saphenous vein insufficiency. We observed 5 iatrogenic arteriovenous fistulas (AVFs) following thermal ablation of the great saphenous vein (GSV). Postprocedure duplex ultrasound (DUS) results were analyzed for the presence of AVF in any location along or adjacent to the treated saphenous veins. Cases were prospectively followed. English literature was reviewed for any other published reports of AVF after EVTA. Data were compiled using our 5 cases, 2 cases were shared with us by colleagues and 20 cases were reported in the literature. Our center has performed more than 4000 (4155) cases of EVTA over the past 15 years. Five cases of AVFs were detected, 3 were found in asymptomatic patients during routine post-EVTA surveillance. The additional 2 cases presented with signs or symptoms which prompted a DUS after ablation. Including cases in the literature, we were able to identify 2 different types of AVFs. The first type of AVF was demonstrated in 13 cases where the AVF occurred along the treated vein. All of these cases involved ablation of the GSV and 90% of these showed signs of recanalization. The second type of AVF was seen in 14 additional cases where the AVF involved a vein segment adjacent to or remote from the ablated vein. The second type occurred in the GSV in 5 cases, external iliac vein (EIV) in 3 cases, and in the popliteal vein in 5 cases. There is 1 reported case of AVF involving the sural artery after perforator vein EVTA. Three of the type 1 cases were followed and spontaneously resolved; 3 of the type 1 cases were treated with surgical ligation with unreported outcomes. Seven cases did not report any follow-up information. Seven of the type 2 cases were treated, and had spontaneous resolution and 7 were not treated. The follow-up on these cases ranged from 1 month to 6 years. Thermal ablation can result in AVF either along the length of the treated vein or adjacent to the area of ablation. Further study would help elucidate the cause and treatment algorithms.

May-Thurner Syndrome in Pregnancy [7K

INTRODUCTION: Thromboembolic disease is responsible for approximately 11% of maternal deaths in the United States. May-Thurner syndrome occurs when compression by the right common iliac artery against the fifth lumbar vertebra causes left common iliac vein obstruction and thrombosis. The incidence is 22-24%. It increases the risk for deep vein thrombosis. Pregnancy and oral contraceptives are risk factors. Diagnosis is by CT, MRI and venography. If anticoagulation therapy is not effective, angioplasty and endovascular stenting are needed. If undiagnosed and untreated, the patient can develop post-thrombotic syndrome with chronic edema, pain, hyperpigmentation, varicosities and skin ulcerations. METHODS: A 34 year old female G3 P0020 at 27 weeks gestation presented with left thigh, groin and gluteal region swelling and pain. Doppler studies were negative. Symptoms persisted and MRI/MRV diagnosed thrombosis of the left common and external iliac veins. The only antecedent precipitating event was a 2.5 hour plane flight 10 days prior. Screening for hypercoagulable disorders was negative. The patient was placed on Lovenox antepartum, anti Xa levels followed and continued postpartum for 6 weeks. MRV 2 months postdelivery revealed partial recanalization of vessels. In her second uneventful pregnancy, the patient initiated early care, was started on Lovenox, and delivered vaginally. CONCLUSION: May-Thurner syndrome is a rare condition with significant morbidity and mortality. Apart from pregnancy, this patient had no risk factors. The continuing symptoms prompted an appropriate diagnosis by MRV. Immediate anticoagulant treatment helped to prevent post-thrombotic syndrome. A high index of suspicion is needed to avoid misdiagnosis.

Defining the utility of anteroposterior venography in the diagnosis of venous iliofemoral obstruction

BackgroundIntravascular ultrasound (IVUS) is the current standard for the diagnosis of obstruction in the iliac and femoral veins. However, multiple venographic findings including collaterals, pancaking, and contrast thinning have been suggested to improve the sensitivity of venography. The objective of our study was to further elucidate where and how anteroposterior venography may successfully guide the diagnosis of venous obstruction. MethodsA retrospective review of patients with chronic venous insufficiency who received iliofemoral stenting by a single practitioner at a tertiary medical center between January 2014 and August 2016 was performed. Patients who had records of anteroposterior venography and IVUS were included. Patients who underwent reoperation, did not have complete records of venography and IVUS, or had preoperative acute deep vein thrombosis were excluded. All patients with a greater than 50% luminal area reduction by IVUS underwent balloon angioplasty and stent placement. The locations of stenosis, collaterals, pancaking, and contrast thinning with venography, the locations of stenosis with IVUS, and the location of each stent placed were recorded. ResultsThere were 107 patients who underwent venous stenting guided by venography and IVUS in this study. Six patients who underwent reoperation, 1 patient who had an acute preoperative deep vein thrombosis, and 14 patients who had incomplete records were excluded. Thus, 86 patients with 77 left lower extremity and 68 right lower extremity studies were available for analysis. The sensitivity by stenosis on venography was 4% in the left common iliac vein (CIV), 44% in the left external iliac vein (EIV), and 44% in the common femoral vein (CFV). The sensitivity by stenosis on venography in the right CIV, EIV, and CFV was 21%, 46%, and 40%, respectively. Combined, pancaking and collaterals had a sensitivity of 97% in the left CIV. IVUS resulted in a change in plan in 2%, 32%, and 48% of patients in the left CIV, EIV, and CFV, and in 26%, 35%, and 48% of patients in the right CIV, EIV, and CFV, respectively. ConclusionsAnteroposterior venography can indirectly diagnose obstruction of the left CIV through the identification of collaterals and pancaking. The combination of low sensitivity and a high rate of change of plan owing to IVUS precludes complete reliance on anteroposterior venography for the diagnosis of lesions in the left EIV and CFV and the right CIV, EIV, and CFV. IVUS must be used to comprehensively identify all venous iliofemoral lesions.

Deep vein thrombosis in patient with pulmonary tuberculosis: a rare and interesting causative link?

Pulmonary tuberculosis is a devastating disease affecting millions of people in developing countries such as India. Many complications of this disease are known, however only few of its hematological complications have been reported. Discovery of its unknown thrombogenic potential is one such disturbing new entity. Tuberculosis can induce a hypercoagulable state and can lead to thromboembolic complications and deep vein thrombosis. Here we report an interesting and rare case of 20-year-old male, newly diagnosed case of Pulmonary Tuberculosis presenting with complaints of acute onset right lower limb swelling and pain. He was diagnosed with thrombosis of external iliac vein. All possible causes for a provoked deep vein thrombosis were evaluated for and ruled out. The patient was started with first line anti tubercular treatment-rifampicin, isoniazid, pyrizinamide, ethambutol along with anti-thrombotics injection enoxaparin and warfarin and followed up for 6 months. He made complete recovery of both his pulmonary and limb disease.

Lower Extremity Blood Flow Velocity in Obese versus Nonobese Pregnant Women.

Obesity and pregnancy are risk factors for venous thromboembolism (VTE). In nonpregnant individuals, abdominal obesity is associated with venous insufficiency. This study aimed to compare venous Doppler volume flow and velocity in the lower extremities of obese versus nonobese women. A prospective cohort study was performed. Duplex ultrasound examined bilateral lower extremity venous flow and velocity (time-averaged mean velocity, TAMV). Flow was analyzed at the superficial femoral (SFV), distal external iliac (DEI), common femoral, profunda femoris, and popliteal veins. Mann-Whitney U-test, Spearman's correlation, and chi-square tests were used, with a significance of p < 0.05. Left SFV TAMV and volume flow were higher in the obese group (5.1 [4.1-5.7] vs. 2.8 [1.7-3.4] cm/second; p < 0.001) and (89 [73-119] vs. 48 [26-62] cm/minute; p = 0.005). Significant differences were noted for right DEI flow (obese 326 [221-833] vs. nonobese 182 [104-355] cm/minute; p = 0.049). The right femoral profunda flow was also higher in obese (49 [40-93] cm/minute) compared with nonobese (31 [22-52] cm/minute; p = 0.041). Volume flow and TAMV in the lower extremities of obese gravidas are higher compared with nonobese ones. Thus, the increased risk of VTE among obese pregnant women may not be caused by venous stasis.

In-Stent Restenosis After Iliocaval Stenting–Characteristics and Outcomes

With increasing use of iliocaval stenting, complications of such stenting have also become more common. In-stent restenosis (ISR), an outcome that is responsible for a majority of reinterventions, is one that has not been studied in detail. Characteristics of ISR in addition to outcomes after reintervention are evaluated. A retrospective review of contemporaneously entered electronic medical record data on 372 limbs with initial unilateral iliocaval stents (247 left and 125 right) placed during a 3-year period from 2015 to 2017 was performed. ISR was estimated from stent and flow channel diameters measured using duplex ultrasound. Characteristics evaluated included onset of ISR after stent placement and progression over time. Regression analysis was performed to evaluate risk factors for development of ISR. Outcomes after reintervention for ISR were also appraised. Kaplan-Meier analysis was used to assess stent patency afater intervention; paired t-test was used to examine preintervention and postintervention outcomes. There were 361 limbs that underwent stenting for stenotic lesions, whereas 11 underwent stenting for chronic native vein occlusions. ISR was noted as early as postintervention day 1. It progressed to a maximal value by 6 months and stabilized thereafter. The overall median ISR across stented common femoral, external iliac, and common iliac segments at 12 months was 43.75%. The segment most commonly affected by ISR was the external iliac vein (77.5%). Up to 89% of stents can have some degree of ISR at 12 months. Variables evaluated as predictors for ISR included age, sex, thrombophilia, thrombotic or nonthrombotic lesion, inflow, stent compression, shear rate, and flow rate. Of these, only lack of stent compression was a significant predictor of ISR at 6 and 12 months. During a median follow-up of 13 months, 50 of 372 (13%) limbs underwent reintervention for ISR and 12 (3%) underwent reintervention for stent occlusion (8 acute [<30 days] and 4 chronic [>30 days]). After reintervention, the Venous Clinical Severity Score improved from 6 to 4 for the ISR cohort (P < .001). Median primary, primary assisted, and secondary patencies after reintervention for ISR were 37, 38, and 17 months, respectively. ISR occurs early after iliocaval stenting but stabilizes around 6 months. Progression of ISR to stent occlusion is rare. No statistically significant, modifiable predictor for ISR was noted. After reintervention for ISR, good clinical outcomes and stent patencies can be expected.