External Iliac Vein Research Articles

Evaluation of 3-dimensional rotational venography for the diagnosis of non-thrombotic iliac venous lesion.

The purpose of this study was to determine the technical feasibility and safety of 3D rotational venography (3D-RV) in the diagnosis of non-thrombotic iliac vein lesions compared with traditional 2D-digital subtraction angiography (2-DSA). The general epidemiological data (including age, gender), clinical manifestations (including major symptom, affected extremity, CEAP classification, comorbidity, stenosis rate), and intra-operative findings (iliac vein indentation position, collateral circulation, procedure time, X-rays dose, contrast agent dosage) of 61 NIVL patients who were assessed by 3D-RV and traditional 2-DSA between October 2018 to October 2022 were obtained and analyzed. A total of 61 consecutive patients with symptomatic NIVL from our institution were enrolled in this study. With the aggravation of iliac vein stenosis, the proportion of indicators such as contralateral formation and iliac vein compression indentation reflecting the severity of compression under 3D-RV reconstruction increased significantly. Also, significant differences were observed between the 3D-RV and 2-DSA groups concerning procedure time (10.56 ± 0.09 s vs. 12.59 ± 0.37 s; p < 0.01), X-ray dose (41.25 ± 0.21 mGy vs. 81.59 ± 1.69 mGy; p < 0.01) and contrast agent dosage (21.48 ± 0.24 mL vs. 33.69 ± 0.72 mL; p < 0.01). Contralateral iliac vein imaging (p = 0.002), pelvic collateral vein imaging (p = 0.03), and external iliac vein indentation (p = 0.001) were found to influence the severity of iliac vein compression. 3D-RV can display dynamic stereo image information of NIVL, augmenting the information obtained from traditional 2-DSA. Contralateral iliac vein imaging, pelvic collateral vein imaging, and external iliac vein indentation can be used to evaluate the severity of iliac vein compression to some extent.

A rare case of KILT syndrome in Ireland: A case report

Venous thromboembolism (VTE), comprising deep vein thrombosis (DVT) and pulmonary embolism (PE), is associated with significant morbidity and mortality. Congenital absence of the inferior vena cava (IVC) is reported in current literature as a rare risk factor for DVT. The presence of kidney and IVC abnormalities on computed tomography together with lower limb thrombosis is collectively referred to as KILT syndrome (Kidney and IVC Abnormalities with Leg Thrombosis), an extremely rare cause of extensive bilateral lower limb DVT.We present a case of KILT syndrome, diagnosed for the first time after the age of 60 years and the first case reported in the Irish population. The patient presented to the emergency department with unilateral limb pain with a prior history of provoked DVT. Clinical gestalt, a high Wells Score, and raised D-Dimer strongly supported a diagnosis of DVT. Lower limb duplex ultrasound confirmed bilateral external iliac and femoral vein thrombus, with computed tomography venography revealing an absent infrarenal IVC and atrophy of the left kidney. The medical team subsequently admitted the patient for therapeutic anticoagulation and investigation. After review by haematology, the patient was discharged on an indefinite duration of anticoagulation with follow-up with our coagulation services. In any patient with bilateral lower limb DVT, comprehensive assessment and investigation, with particular emphasis on imaging, is imperative to exclude rare associated conditions.

Iliac vein stent failure in community practice and results of corrective reinterventions

ObjectiveThe goal of endovenous stenting is to relieve venous obstruction and reduce peripheral venous hypertension by using large caliber venous stents in the presence of adequate venous inflow and outflow for the stented conduit. The aim of this report is to describe the technical reasons and outcomes for reinterventions in a subset of patients who had a history of iliac vein stenting and were now referred to us at a specialty venous clinic for further care. MethodsFrom January 2016 to December 2021, records of all patients who were referred to us with a history of iliac vein stenting performed at an outside facility and who had a reoperation performed at our center were retrospectively analyzed. ResultsA total of 149 limbs underwent a deep venous reintervention after a failure of a trial of conservative therapy. The mean age of the sample was 57 ± 16 years. The ratio of non-thrombotic iliac vein lesions to post-thrombotic lesions was 1:2.5. The majority of the patients (84%) were CEAP class C4 or higher. The most common reason for reintervention was stent occlusion (74%), followed by iatrogenic stenosis (53%) and in-stent restenosis/shelving (38%). There was a trend for improvement in all clinical parameters (venous clinical severity score, visual analog scale for pain, and edema grade) after the reintervention. Poor inflow was present in 70% of limbs with stent occlusion. The median diameters of stented common femoral vein, external iliac vein, and common iliac vein prior to reintervention were 12, 12, and 13 mm, respectively. The median diameters of stented common femoral vein, external iliac vein, and common iliac vein after reintervention were 14, 15, and 16 mm, respectively. Eighty-eight percent of limbs required at least one further reintervention after initial reoperation. ConclusionsVenous reoperations are generally infrequent and required in a small number of patients. Poor inflow appeared to be a common cause of stent occlusion. Iatrogenic stenosis is another common reason for venous reoperation and is difficult to fully rectify through current endovascular techniques and tools. Use of intravascular ultrasound planimetry routinely in every deep venous intervention and thorough knowledge of the principles of venous stenting outlined in this report may help forestall the need for reoperative deep venous surgery in some cases.

SJLA_2024_A16: Unusual Complications of Open Preperitoneal Tension-Free Inguinal Hernia Repair

Background: The purpose of this study is to report two patients referred to our hospital after developing unusual complications attributed to prior open preperitoneal tension-free inguinal hernia repair. Methods: Case # 1 A 75-year-old male developed a left proximal thigh abscess requiring incision and drainage 5 years after open prosthetic, preperitoneal inguinal hernia repair with single-layer mesh. A pelvic computed tomography (CT) scan demonstrated an abscess in the left inguinal preperitoneal space as well as diverticulosis but no diverticulitis. A colonoscopy was negative for any additional findings. The patient underwent groin exploration, debridement of the inguinal canal and sinus tract, and mesh resection followed by JP drain placement. The inguinal defect was repaired utilizing the should ice technique. Intraoperative cultures revealed penicillin-resistant Staphylococcus aureus. The drain was removed on postoperative day nine, and his recovery remains uneventful without hernia recurrence or infectious complications at 11-month follow-up. Case # 2 An 82-year-old man developed progressive left lower extremity edema and disabling claudication 1 month after open prosthetic inguinal hernia repair with a bilayer disc mesh. Venous duplex imaging revealed compression of the left common femoral and external iliac veins. A CT angiogram demonstrated left external iliac and common femoral artery thrombosis and a 5.2 cm fluid collection consistent with hematoma. An inferior vena cava filter was placed. The common femoral artery was controlled after initial exploration revealed a common femoral artery pseudoaneurysm. The mesh was densely adherent to the external iliac vein and was thus not resected. The common femoral artery pseudoaneurysm was repaired and the profunda femoris artery over sewn. An external iliac to superficial femoral artery 8 mm Polytetrafluoroethylene bypass graft was placed. The patient was discharged on systemic anticoagulation without claudication on postoperative day thirteen. Results: Laparoscopic inguinal hernia repair and novel, open techniques and mesh devices have popularized the placement of mesh in the preperitoneal space. Acute, severe vascular complications and latent infectious complications can occur after open, preperitoneal tension-free inguinal hernia repair and may require remedial surgery. CT scans and angiogram pictures are available. Discussion: Laparoscopic inguinal hernia repair and novel, open techniques and mesh devices have popularized the placement of mesh in the preperitoneal space. Acute, severe vascular complications and latent infectious complications can occur after open, preperitoneal tension-free inguinal hernia repair and may require remedial surgery. CT scans and angiogram pictures are available. Conclusion: Laparoscopic inguinal hernia repair and novel, open techniques and mesh devices have popularized the placement of mesh in the preperitoneal space. Acute, severe vascular complications and latent infectious complications can occur after open, preperitoneal tension-free inguinal hernia repair and may require remedial surgery. CT scans and angiogram pictures are available.

May-Thurner Syndrome: a case of unilateral left lower limb deep vein thrombosis

The May–Thurner Syndrome (MTS) is a rare anatomical condition in which the compression of the left common iliac vein by the right common iliac artery causes an outflow obstruction, presenting frequently as chronic venous insufficiency or deep venous thrombosis (DVT). This variant is rarely considered when investigating DVT, especially in patients with other risk factors. MTS requires careful workup and management to avoid complications such as chronic venous insufficiency, post-thrombotic syndrome, and primary lymphedema. The authors present a 63-year-old woman admitted to the emergency department with a 24-hour history of left lower limb pain and edema. Initial assessment, with computed tomography of the lower left limb and pelvis, showed compression of the left common iliac vein with an extensive thrombus of the left common iliac and external iliac veins, as well as femoral and popliteal left veins, consistent with MTS. Therapeutic enoxaparin initially implemented, was then switched to oral anticoagulation. At 6 months reevaluation, venous duplex ultrasound showed only partial recanalization of the femoral vein. Investigation for May-Thurner Syndrome in patients with left lower limb venous thrombotic events, regardless of risk factors, should always be present since the establishment of an effective therapeutic plan and eventually, endovascular treatment can minimize the long-term sequelae of deep vein thrombosis.

Клиническое наблюдение травмы магистрального сосуда при имплантации трехкомпонентного фаллопротеза

Injury of iliac vessels is one of the most disastrous complications of penile prosthesis implantation. There are no detailed descriptions of such cases in world literature. In this article, we present the clinical case of injury to the external iliac vein during the implantation of a three-piece penile prosthesis with particular emphasis on the consequences of such complication in the postoperative period. The article comprises a brief review of the literature on the methods of ectopic placement of the penile prosthesis reservoir.

Intravascular Ultrasound in Treating Iliac Vein Compression With Endovascular Stenting: A Necessary Tool for Optimal Outcomes.

Symptomatic compression of the left common iliac vein between the right common iliac artery and spinal vertebrae is referred to as May-Thurner Syndrome (MTS). Atypical cases of MTS including compression of the left external iliac vein, right iliac vein or the inferior vena cava can also coexist and cause double vein compression. Current literature suggests that endovascular treatment including thrombolysis, thrombectomy, venoplasty and stent placement to correct the mechanical obstruction together with anticoagulation therapy is safe and a reasonable management for patients with MTS. Intravascular ultrasound (IVUS) can aid in the diagnosis and the operative planning of MTS, especially regarding sizing and precise deployment of venous stents. Here we present 2 unique atypical cases of MTS with double left iliac vein compression treated endovascularly with stent placement along the common and external iliac vein with the assistance of IVUS.

Controversies in the management of proximal deep vein thrombosis.

Controversies in the management of proximal deep vein thrombosis.

Spontaneous Left External Iliac Vein Rupture.

Spontaneous rupture of the Iliac Vein is very rare in practice. In over 90% of cases, the venous lesion is located on the left side. The exact etiology of this condition is unknown. Spontaneous injury of the iliac vein is thought to be favored by intense exercise, constipation, cough, labor, May-Thurner syndrome or pre-existing inflammatory changes in the venous wall are also implicated. We present the case of an 83-year-old woman who is brought to the Emergency Department for abdominal pain located in the left flank and in the left iliac fossa, which appeared after a medium physical exertion. After an emergency contrast-enhanced abdominal CT scan, the diagnosis of spontaneous rupture of the left external iliac vein is established. Surgery is performed with extreme urgency by retroperitoneal approach and due to the very precarious condition of the patient, venous ligation is done, wishing to perform a Palma-Dale venous bypass at a later time. Although a rare cause of spontaneous retroperitoneal hematoma, a non-traumatic rupture of the common or external iliac vein should be considered in patients in shock with massive retroperitoneal bleeding, accompanied by a high mortality rate.

Assessment of flow mechanics in the lower extremity venous system

BackgroundThe Reynolds number (Re) is a dimensionless parameter that describes fluid flow mechanics. Veins are compliant and collapsible vascular conduits that can accommodate large volume changes in response to small pressure changes. However, only sparse information is available about flow parameters such as the Re in the venous system. MethodsBilateral duplex ultrasound examination of 15 healthy volunteers (30 limbs) was performed before and after exercise (four flights of stairs) of the veins of the lower extremity (left and right sides) and inferior vena cava. These volunteers had been confirmed to not have any signs or symptoms of lower extremity venous disease via focused history and physical examination findings. ResultsMost of the volunteers were women (73%). Their mean age was 37 ± 12.8 years. The Re was highest in the inferior vena cava among all the veins examined (470 ± 144 before exercise and 589 ± 205 after exercise; P = .04). The association between the change in Re before and after exercise and the specific vein examined was also significant for the right and left external iliac veins, right and left common femoral veins, right and left profunda femoris veins, right and left femoral veins, and right common iliac vein. Resistance and velocity maps for the lower extremity venous system were also created. The velocity increased and the resistance decreased as one moved up the venous tree toward the right atrium. ConclusionsThe Re increased for most of the lower extremity veins after exercise in our healthy volunteers. However, the critical value for turbulent flow was not reached despite the exercise.

Robotic-Assisted Resection of Pelvic Arteriovenous Malformation Utilising Intraoperative Video Angiography with Indocyanine Green

<h3>Study Objective</h3> Surgical resection of pelvic arteriovenous malformations (AVM) can be challenging, and pre-operative imaging may not clearly identify feeding vessels. We describe a case of pelvic AVM in a young woman and demonstrate the robotic surgical resection utilising video angiography with indocyanine green (ICG). <h3>Design</h3> Case report and surgical video. <h3>Setting</h3> Four-arm robotic assisted laparoscopy. <h3>Patients or Participants</h3> A nullipara with pelvic AVM. <h3>Interventions</h3> Robotic-assisted resection of pelvic AVM guided by intraoperative ICG angiography. <h3>Measurements and Main Results</h3> A 22-year-old woman presented with progressively worsening left pelvic pain. Pelvic ultrasound demonstrated a 7cm left adnexal vascular mass and magnetic resonance angiogram confirmed a left pelvic AVM. The patient was counselled regarding the risks of embolization versus surgery and decided on the latter. Using a robotic surgical system, the left pelvic side wall was opened at the pelvic brim and careful dissection of the retroperitoneal alveolar tissue was performed. 3mL of a 2.5mg/mL solution of ICG was injected peripherally, followed by 10mL bolus of normal saline. Using the near infra-red imaging of the robotic system, the ICG demonstrates small efferent vessels arising from the left ovarian vessels and a large vein communicating with the left external iliac vein. Vascular clips were applied to the aberrant vein prior to ligation. The AVM was carefully dissected away from the surrounding tissues, with use of bipolar diathermy for coagulation of smaller vessels. A further dose of ICG was injected after resection to ensure haemostasis and to confirm the perfusion of remaining organs. Mesosalpinx and pelvic side wall peritoneum were closed with 2-0 barbed suture. The patient was discharged the following day with complete resolution of left pelvic pain and normal pelvic ultrasound scan 6 weeks later. <h3>Conclusion</h3> Robotic surgical resection of pelvic AVM is enhanced with guidance from intraoperative ICG video angiography to ensure haemostasis and complete excision.

Manual Compression of External Iliac Vein to Increase the Size of Femoral Vein for Femoral Central Venous Catheter Insertion in Small Children: Pilot Experimental Study and Randomized Trial

Highlights Abstract Aim: Pediatric femoral central venous catheter insertion is sometimes difficult due to small vein size. External iliac vein (EIV) compression may provide a tourniquet effect to the femoral vein (FV) and may facilitate catheterization. This study was conducted to determine the effect of EIV compression on FV size and femoral venous catheterization success rates. Methods: This study had 2 parts. The first part was a single-arm experimental study. The second part was a randomized controlled trial. Children weighing 2.5–15.0 kg were included. First part: All patients received the same intervention and measurements. FV anteroposterior and medial-lateral diameters were measured by ultrasound without EIV compression, after which EIV was compressed using the assistant’s finger, and FV diameters were measured. Second part: Patients were randomized into compression and control groups. The compression group received EIV compression during femoral venous catheterization. The control group did not receive the compression. Results: A total of 30 patients (15 in each group) participated. EIV compression significantly increased FV anteroposterior diameter (3.36 ± 1.01 mm with compression, 2.39 ± 0.76 mm without compression, mean difference = 0.97 mm, 95% CI = 0.73, 1.21, P &amp;lt; 0.001) and medial-lateral diameter (4.58 ± 1.40 mm with compression, 3.86 ± 1.32 mm without compression, mean difference = 0.72 mm, 95% CI = 0.43, 1.01, P &amp;lt; 0.001). Catheterization success rates were not different between groups. Conclusions: EIV compression increased FV size, but the effect on femoral venous catheterization success rates was inconclusive due to a small sample size.

External iliac vein dimensions can change after placement of a more proximal iliac vein stent

ObjectiveWe have occasionally observed during vein stenting for proximal iliac vein stenosis, the appearance of a more distal stenosis in the iliac vein that had not been initially observed before placement of the more proximal vein stent. In the present retrospective study, we aimed to document this observation. MethodsWe identified patients in whom changes in the area measurement and linear dimensions of the external iliac vein (EIV) were observed on venography and/or intravascular ultrasound (IVUS) after stent placement for chronic nonthrombotic iliac stenosis in the common iliac vein (CIV). The images of these IVUS scans were subsequently analyzed to determine the cross-sectional area, major axis, and minor axis measurements in the EIV, before and after placement of a proximal CIV stent. ResultsA total of 32 limbs with complete and quality IVUS and venography images available that allowed for measurement of the EIV before and after vein stent placement in the CIV were evaluated. The patient cohort was 55% men, with a mean age of 63.8 ± 9.9 years and a mean body mass index of 27.8 ± 7.8 kg/m2. Of the 32 limbs, 18 were left sided and 14 were right sided. Most (n = 12 [60%]) of the limbs had presented with venous-related skin changes (C4 disease). The remainder of the cohort had had active (C6 disease; n = 4 [20%]) or recently healed (C5 disease; n = 1 [5%]) venous ulceration and isolated venous-related edema (C3; n = 3 [15%]). The minimal CIV area before and after CIV stenting was 28.47 ± 23.53 mm2 and 196.34 ± 42.62 mm2, respectively. The minimal mean EIV cross-sectional area before and after CIV stenting was 87.44 ± 38.55 mm2 and 50.69 ± 24.32 mm2, respectively, a statistically significant reduction of 36.75 mm2 (P < .001). The mean EIV major axis and minor axis had both decreased similarly. The minimal mean EIV major axis before and after CIV stenting was 15.22 ± 3.13 mm and 11.13 ± 3.58 mm, respectively (P < .001). The minimal mean EIV minor axis before and after CIV stenting was 7.26 ± 2.40 mm and 5.84 ± 1.42 mm, respectively (P < .001). ConclusionsThe results from the present study have shown that the dimensions of the EIV can change significantly after placement of a proximal CIV stent. Possible explanations include masked stenosis due to distal venous distention resulting from the more proximal stenosis, vascular spasm, and anisotropy. The presence of proximal CIV stenosis can potentially lessen the appearance, or completely mask the presence, of an EIV stenosis. This phenomenon appears unique to venous stenting, and the prevalence is unknown. These findings underscore the importance of completion IVUS and venography after venous stent placement.

Effects of different routes of administration and doses of Sulodexide on leukocyte-endothelium interaction and tissue perfusion on an animal model of low flow and high pressure in veins.

To assess the effects of different doses and routes of Sulodexide on leukocyte-endothelium interaction and tissue perfusion in a model of venous hypertension and low blood flow. Six weeks after venous hypertension induction, through external iliac vein ligature male hamsters (Mesocricetus auratus) received Sulodexide at 1, 2, or 4mg/kg/day or saline (placebo) by subcutaneous or intramuscular routes during 2 or 4weeks. After treatments, leukocyte rolling and adhesion, functional capillary density (FCD), and venular diameter were evaluated on the affected hindlimb. Subcutaneous and intramuscular treatments with Sulodexide after 2 and 4weeks, significantly reduced leukocyte rolling and adhesion and increased FCD. Sulodexide did not affect venular diameter and intramuscular treatment was more effective in reducing leukocyte adhesion than the subcutaneous one. This preliminary study demonstrated that Sulodexide significantly decreased leukocyte-endothelium interaction and improved tissue perfusion in hamsters subjected to venous hypertension and low blood flow.

INTRACEREBRAL HEMORRHAGE POSTPHARMACOMECHANICAL CATHETER-DIRECTED THROMBOLYSIS: CAN WE PREVENT IT?

INTRACEREBRAL HEMORRHAGE POSTPHARMACOMECHANICAL CATHETER-DIRECTED THROMBOLYSIS: CAN WE PREVENT IT?

S2692 Abscess-Enteric Fistula of Failed Kidney Transplant Presenting With Gastrointestinal Bleeding

Introduction: Lower gastrointestinal (GI) bleeding is a common occurrence, with the vast majority of cases being due to diverticula, vascular ectasias, cancers, and hemorrhoids. In rare cases, a large vessel can form a fistula with the GI tract, causing bleeding. We present a case where an abscess surrounding a failed transplant kidney eroded into the external iliac vein and presented as a slow lower GI bleed. Case Description/Methods: A 65-year-old man with a failed renal transplant and known colovesicular fistula presented with hypotension. Labs showed a significant leukocytosis, an elevated lactate, and a hemoglobin of 6.3 g/dL. He was started on broad spectrum antibiotics, and then developed intermittent episodes of small-volume bright red blood per rectum. The patient had an upper endoscopy and colonoscopy one month prior for GI bleeding which had not identified a source. Computed tomography angiography of the abdomen and pelvis revealed a fistulous communication between the sigmoid colon and a multiloculated right lower quadrant collection (Figure). The collection encased the transplanted kidney and right iliac vasculature. Extraluminal extravasation of intra-arterial contrast was noted, concerning for either active arterial bleed or pseudoaneurysm. The patient underwent emergent exploratory laparotomy which revealed a necrotic transplant kidney densely adhered to the surrounding colon and a right external iliac artery pseudoaneurysm. Bleeding was noted from a defect in the right external iliac vein. The kidney was removed, the pseudoaneurysm was stented, and the vein defect was oversewn. Unfortunately, the patient had a complicated post operative course and died. Discussion: In patients with evidence of small-volume rectal bleeding but a clinical picture concerning for a more significant bleed, cross-sectional imaging can be necessary to make the appropriate diagnosis. In this case, imaging identified the abscess-enteric fistula, and laparoscopy revealed that the bleeding was due to a defect in the iliac vein. Abscess-enteric fistulas are associated with post-surgical states or small localized perforations. This patient likely developed a microperforation that infected the failed transplant kidney, creating an abscess which eroded into the iliac vein. GI bleeding was only intermittent and a source was not identified on prior luminal imaging, possibly due to the small size of the fistula tract. This pathology is unfortunately not amenable to endoscopic intervention and often requires surgery.Figure 1.: Computed tomography angiography of the abdomen and pelvis with a multiloculated right lower quadrant collection encasing a transplanted kidney and right iliac vasculature.

Pharmacomechanical Aspiration Thrombectomy of Iliofemoral Deep Venous Thrombosis to Salvage the Transplanted Kidney - A Case Report

Ipsilateral acute iliofemoral deep venous thrombosis (DVT) after a renal transplantation, although rare, has a high morbidity, causing complications such as allograft failure, rupture, or death. Treatment modalities are limited due to the risk of bleeding and impaired renal function. We report successful treatment of a case of iliofemoral DVT in a 58-year-old male recipient of a living donor renal transplantation. The immediate postoperative course of the patient was uneventful, and he was discharged on 6th postoperative day (POD) with serum creatinine of 0.8 mg/dl. On POD 26, the patient was admitted with diarrhea, dehydration, and decreased urine output. His serum creatinine rose from 0.8 mg/dl to 2.6 mg/dl and he developed pain and swelling of the right lower extremity. Duplex ultrasonography was suggestive of acute DVT with noncompressible right distal external iliac vein, common femoral, superficial femoral and popliteal veins, absence of color flow from the right femoral vein to the common iliac vein, dilatation of allograft renal vein and an increased renal graft resistive index of 0.97. After inferior vena cava filter insertion, initial treatment with percutaneous balloon angioplasty and catheter-directed thrombolysis could not restore blood flow. Subsequently, percutaneous transluminal pharmacomechanical aspiration was performed with complete removal of the thrombus leading to restored renal allograft vein patency and normalization of allograft function and Duplex findings.

A practice audit of short-term outcomes of Wallstents versus Venovo stents for the treatment of nonthrombotic iliac vein outflow stenoses

ObjectiveThe Wallstent (WS; Boston Scientific, Malborough, MA) is currently the standard of care for comparisons of clinical efficacy for new stent devices in the treatment of iliac vein outflow disease. Many vein-specific Nitinol-based stents have been now approved by the Food and Drug Administration for use in the iliofemoral venous system. However, few comparisons of these devices to the current standard have been reported. The purpose of this investigation was to compare the complication and reintervention rates between the WS and Venovo stent (VS; BD, Franklin Lakes, NJ). MethodsA random sample of 100 WS and 100 VS cases performed from April 2018 through December 2020 were selected for retrospective analysis. The demographics, presenting symptoms, and CEAP (Clinical, Etiology, Anatomy, Pathophysiology) class were assessed. The complication logs and 90-day follow-up data were reviewed for every case to assess the incidence of postoperative deep vein thrombosis, stent thrombosis, in-stent restenosis, bleeding, and transient back pain. ResultsWSs had been placed more often in the left common iliac vein segment (52 vs 1), and VSs had been placed more often in the left common iliac vein and external iliac vein segments (36 vs 63; P = .0069). The average diameter and length of the WSs and VSs were 19.7 ± 2.2 mm vs 15 ± 1.4 mm (P = 2.4∗10−44) and 80.8 ± 9 mm vs 117.6 ± 20.4 mm (P = 2.4∗10−38), respectively. The average number of stents per patient was 1.05 for the WSs and 1.03 for the VSs (P = .47). The reintervention rates were similar between the two groups: WS, n = 5; and VS, n = 4 (P = .74). Four of the five WS reinterventions were stent extensions to treat in-stent restenosis and recurrence of symptoms, and one was secondary to occlusion requiring ipsilateral venoplasty and stenting. Two of the four VS reinterventions were venoplasty for in-stent restenosis and two were stent extensions for symptom recurrence. Transient back pain was the most common complication (WS, 37%; VS, 47%; P = 0.28). Insertion site deep vein thrombosis had developed in the three patients in the WS group and four patients in the VS group (P = .71). No patient had experienced bleeding requiring hospitalization, and no stent fractures, stent migration, or deaths had occurred. ConclusionsThe complication and reintervention rates between the WS and VS groups were similar. Both stents demonstrated evidence of in-stent stenosis requiring reintervention. Implanted VSs tended to be smaller in diameter and longer in length and covered the common and external iliac veins more often compared with the WSs. Therefore, one VS can be used to cover two territories compared with the WS for which two stents will be required to cover the same vein territory length.

Thromboembolic events after Ad.26.COV2.S COVID-19 vaccine: Reports to the Vaccine Adverse Event Reporting System.

PurposeThe Food and Drug Administration (FDA) has identified a potential safety concern for thromboembolic events (TEEs) after Ad.26.COV2.S COVID‐19 Vaccine. We sought to characterize the frequency, severity, type, and anatomic location of TEEs reported to the Vaccine Adverse Event Reporting System (VAERS) following Ad.26.COV2.S.MethodsReports of TEEs after Ad.26.COV2.S were identified in VAERS, and demographics, clinical characteristics, and relevant medical history were summarized. For a subset of reports, physicians reviewed available medical records and evaluated clinical presentation, diagnostic evaluation, risk factors, and treatment. The crude reporting rate of TEEs was estimated based on case counts in VAERS and vaccine administration data.ResultsThrough February 28, 2022, FDA identified 3790 reports of TEEs after Ad.26.COV2.S. Median age was 56 years, and 1938 individuals (51.1%) were female. Most reports, 2892 (76.3%), were serious, including 421 deaths. Median time to onset was 12 days post‐vaccination. Obesity and ischemia were among the most commonly documented risk factors. Thrombocytopenia (platelet count less than 150 000/μl) was documented in 63 records (11.5%) and anti‐platelet 4 antibodies in 25 (4.6%). Medical review identified cases of severe clot burden (e.g., bilateral, saddle, or other massive pulmonary embolism with or without cor pulmonale; lower extremity thrombus involving the external iliac, common femoral, popliteal, posterior tibial, peroneal, and gastrocnemius veins). The crude reporting rate was ~20.7 cases of TEE per 100 000 doses of Ad.26.COV2.S administered.ConclusionsLife‐threatening or fatal TEEs have been reported after Ad.26.COV2.S, including bilateral massive pulmonary embolism or other severe clot burden.

422.11: Instant Post-reperfusion Thromboinflammation in Clinical Kidney Transplantation and Its Possible Impact on Outcome

Introduction: During the process of transplantation, detrimental events such as ischemia inflict harm to, and change the cell phenotype of organs, which increases the susceptibility to an early innate immune attack post-reperfusion. Here, we present data on a detailed systematic characterization of this early response post-reperfusion and its possible impact on outcome after kidney transplantation. Method: Sixty-three consecutive kidney transplant recipients were included. Twenty-six (41%) and 37 (59%) patients received kidneys from living (LD) and deceased donors (DD), respectively. Fifteen DD-kidneys (41%) were preserved with hypothermic machine perfusion (DDmp) and 22 (59%) were preserved in cold storage (DDcs). Four venous EDTA blood samples were collected intra-operatively at baseline (pre-reperfusion from the external iliac vein) and at 1-, 10- and 30-minutes post-reperfusion from the proximal portion of the transplant vein. Samples were handled according to a meticulous and standardized routine including immediate and sustained cooling with subsequent storage of plasma samples at -80 °C. Biomarkers for the complement, coagulation and contact cascade systems were measured. Clinical outcome data for a total of 24 months were collected. Non-parametric analysis of variances on aligned rank transformed data and receiver operating characteristics (ROC) analyses were used. Results: Patient and graft survival did not differ between DD and LD by 24 months. There were no differences in donor age/BMI between LD and DD recipients. The median kidney-donor-risk-index did not differ between DDcs and DDmp (1.56 vs 1.5). Median cold ischemic times in DDcs and DDmp were 11.4 and 13 hours, respectively. Overall, 6 patients (9.5%, all DD-recipients) experienced delayed graft function (DGF). Thromboinflammation, defined as co-activation of complement (sC5b-9), coagulation (FXIa, thrombin) and contact (FXIIa, KK) cascade systems, was detected instantly post-reperfusion in DD-kidneys (predominantly in DDcs), while being largely absent in LD-kidneys. Analyzing the slopes for serum-creatinine and eGFR between 3 to 24 months post-transplant, the release of sC5b-9 at 30 min post-reperfusion correlated with a higher serum-creatinine and lower GFR slope in DDcs, but not in LD and DDmp. Thrombin, sC5b-9, FXIa and FXIIa were predictive for DGF, de novo DSA and rejection. Conclusion: Instant post-reperfusion thromboinflammation (IPRT) occurs in DD-kidneys exposed to ischemia, while being largely absent in LD-kidneys. This early innate immune response may be associated with impaired mid-term graft function, even in the current population with a low burden of ischemia. Furthermore, markers of IPRT were predictive for outcome measures such as DGF and rejection. Lastly, hypothermic machine perfusion seems to reduce IPRT.