Left Common Iliac Vein Research Articles

Acute left iliofemoral vein thrombosis: Comparison between simple and bony May-Thurner syndrome in CT venography.

To explore the etiology of May-Thurner syndrome (MTS) with acute iliofemoral deep vein thrombosis (DVT) regarding imaging findings and clinical features. We retrospectively analyzed 57 patients with acute left iliofemoral DVT from 2015 to 2020. The diameter of left common iliac vein (LCIV) at the maximal compression site and its percent compression regarding the average diameter of the uncompressed iliac vein were recorded in central and distal portions of the LCIV according to the location in the quadrant of lumbar vertebral body. Compression was categorized into simple and bony MTS; Simple MTS as LCIV compressed by the right common iliac artery (RCIA) versus Bony MTS as LCIV by lower lumbar degenerative changes regardless of RCIA compression. Initial computed tomographic venography (CTV) regarding chronic change of LCIV such as fibrotic atrophy or cordlike obliteration, extent of thrombus, and lumbar degenerative changes were evaluated. Therapeutic effect after initial therapy was assessed in follow-up CTVs after 3-6months. All patients showed LCIV compression with 19 simple MTS (mean age, 42.8 ± 14.1years [23-67years]; 12 females; symptom for 4.4 ± 5.5days) and 38 bony MTS (mean age, 73.0 ± 10.2years [49-85years]; 26 females; symptom for 5.5 ± 4.8days). There was significant difference in age (p < .001) and no significant difference in sex or symptom duration between two groups (p = .691 and 0.415, respectively). All simple MTS showed compression only in the central LCIV and half of bony MTS showed compression in both central and distal LCIV (p < .001). Among the lumbar degenerative changes, symmetric anterolateral osteophyte (p < .001) and asymmetric osteophyte (p < .001) were significantly associated with bony MTS, but not scoliosis (p = .799), compared to simple MTS. Although there was no significant difference in chronic change of LCIV, thrombosis extent, and therapeutic effect between two groups (p > .05), chronic change of LCIV showed significant difference between single and dual compression (23.7% vs. 57.9%, p = .024) and residual thrombus after initial therapy was occurred in 21.1% of single compression and 47.4% in dual compression with non-significant trend (p = .082). Bony MTS related to lumbar degenerative changes with acute iliofemoral DVT occurs in older patients, presenting more than one stenosis at LCIV, inducing more chronic change with possibly weaker therapeutic effect than simple MTS.

May-Thurner Syndrome and Lymphedema Reconstruction.

Background:May-Thurner syndrome (MTS) is an anatomical variant that results in compression of the left common iliac vein by the right common iliac artery. Although often asymptomatic, lower extremity swelling/edema, deep venous thrombosis, post-thrombotic syndrome, and eventual lymphedema (due to long-standing venous obstruction) can develop. The clinical management of patients presenting for lymphedema surgery with concomitant or undiagnosed MTS is not well described.Methods:This review investigates two patients who were evaluated for unilateral lower extremity lymphedema, both of whom were subsequently diagnosed with MTS. Standard imaging (including lymphoscintigraphy, indocyanine green lymphangiography, and magnetic resonance venography) were performed to identify proximal venous obstruction. Treatment was accomplished using vascular surgical management, including stenting of the iliac vein before lymphedema reconstruction with vascularized lymph node transfer and multiple lymphovenous bypass.Results:Both patients we examined in this review had improvement of lymphedema with vascular surgical management. Literature review reveals that MTS has an incidence as high as 20% in the population, although commonly unidentified due to lack of symptomatology.Conclusions:There are no studies documenting the incidence of MTS in patients referred for lymphedema surgical management. Routine studies should be obtained to screen for proximal venous obstruction in patients presenting for surgical management of lower extremity lymphedema. Additional research is needed regarding the approach to managing patients with both MTS and lymphedema. Careful observational and prospective studies may elucidate the appropriate time interval between venous stenting and lymphedema microsurgical reconstruction.

A Murine Model of Hemodialysis Access-related Hand Dysfunction.

Chronic kidney disease is a major public health problem, and the prevalence of end-stage renal disease (ESRD) requiring chronic renal replacement therapies such as hemodialysis continues to increase. Autogenous arteriovenous fistula (AVF) placement remains a primary vascular access option for ESRD patients. Unfortunately, approximately half of the hemodialysis patients experience dialysis access-related hand dysfunction (ARHD), ranging from subtle paresthesia to digital gangrene. Notably, the underlying biologic drivers responsible for ARHD are poorly understood, and no adequate animal model exists to elucidate the mechanisms and/or develop novel therapeutics for the prevention/treatment of ARHD. Herein, we describe a new mouse model in which an AVF is created between the left common iliac artery and vein, thereby facilitating the assessment of limb pathophysiology. The microsurgery includes vessel isolation, longitudinal venotomy, creation of arteriovenous anastomosis, and venous reconstruction. Sham surgeries include all the critical steps except for AVF creation. Iliac AVF placement results in clinically relevant alterations in central hemodynamics, peripheral ischemia, and impairments in hindlimb neuromotor performance. This novel preclinical AVF model provides a useful platform that recapitulates common neuromotor perturbations reported by hemodialysis patients, allowing researchers to investigate the mechanisms of ARHD pathophysiology and test potential therapeutics.

Abstract No. 394 May-Thurner iliac venous compression and clinical presentation with evaluated with 4D Flow MRI

May-Thurner Syndrome (MTS) is caused by compression of the left common iliac vein (LCIV). While imaging findings and clinical manifestations may be associated, these relationships are complex. We aimed to determine whether hemodynamic significance of LCIV compression and related clinical manifestations could be assessed by measuring the relative blood flow in the proximal LCIV and proximal right common iliac vein (RCIV). 4D Flow MRI quantified LCIV and RCIV blood flow and LCIV/RCIV flow ratio was calculated in patients with LCIV compression compared with control patients with no vascular abnormalities (NVA).

Comprehensive anatomy of the superior hypogastric plexus and its relationship with pelvic surgery landmarks: defining the safe zone around the promontory.

Pelvic surgery carries an inherent risk of autonomic nerve injury leading to genitourinary and bowel dysfunction due to the close proximity of the superior hypogastric plexus (SHP). The aim of this study was to define the detailed anatomy of SHP and identify its relationship with the vascular landmarks and ureters for pelvic autonomic nerve-preserving surgery. A cadaveric study on the detailed anatomy of the SHP was conducted in our surgical anatomy research unit. Between 02/2019 and 10/2019, macroscopic anatomical dissections were performed on 45 fresh adult cadavers (39 male, 6 female). Distances between the SHP, major vascular structures, and other anatomical landmarks were measured. Three types of SHP morphology were observed: mesh (64.8%), single nerve (24.4%), and fiber (10.8%). SHP bifurcation was located inferior to the aortic bifurcation in all cases; however, it was observed cranial to the promontory in 80% of the cases, whereas 18% were caudally and 2% were over the promontory. The closest vessels to the left and right of the SHP bifurcation were the left common iliac vein (LCIV) (86.2%, the mean distance was 8.49 ± 7.97mm) and the right internal iliac artery (RIIA) (48.2%, mean distance was 13.4 ± 9.79mm), respectively. At SHP bifurcation level, the lateral edge of the SHP was detected on the LCIV in 22 cases and on the RIIA in 10 cases for the left and right side of the plexus, respectively. The distance between the SHP bifurcation and the ureter was 27.9mm on the right and 24.2mm on the left. The width of the left (LHN) and right hypogastric nerves (RHN) were 4.35mm and 4.62mm at 2cm below the SHP bifurcation, respectively. LHN was on the vascular structures in 13 cases, whereas RHN in only 1 case, 2cm below the SHP bifurcation. Understanding the location of the SHP, including its relationship with important anatomical landmarks, might prevent iatrogenic injury and reduce postoperative morbidity in the pelvic surgery setting.

V06-03 VARIATIONS IN PROMONTORY ANATOMY COMPLICATING ROBOTIC SACROCOLPOPEXY

You have accessJournal of UrologyCME1 May 2022V06-03 VARIATIONS IN PROMONTORY ANATOMY COMPLICATING ROBOTIC SACROCOLPOPEXY Colby P. Souders, Ramy Goueli, Hersh Trivedi, Gaurav Khatri, and Philippe E. Zimmern Colby P. SoudersColby P. Souders More articles by this author , Ramy GoueliRamy Goueli More articles by this author , Hersh TrivediHersh Trivedi More articles by this author , Gaurav KhatriGaurav Khatri More articles by this author , and Philippe E. ZimmernPhilippe E. Zimmern More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002586.03AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Due to the recognized failure rate of some native tissue repairs, the number of robotic-assisted abdominal sacrocolpopexy (rASC) procedures performed is increasing. However, the anatomy of this presacral space can be variable and closely surrounded by critical structures. METHODS: Our video presents fours cases, which highlight our experience with aberrant or challenging anatomy in the presacral space. In particular, we highlight how preoperative MRI with defecography (MRdef) assisted in identifying these anatomic challenges preoperatively. RESULTS: The first patient is a 70-year-old female with vault prolapse. Her pre-operative MRdef found a bulging disc at L5-S1 and a large amount of fat overlying the promontory. With the help of the suction tip and the tip of the scissors, the area of the promontory was finally identified and exposed, despite difficulty due to the thickness of the adjacent fatty meso-colon.The second is a 74-year-old female with vault prolapse. Her MRdef illustrated a large amount of fat over the sacrum. During the rASC, we were unable to identify the precise location of the promontory due to excess fatty tissue. Due to these challenges, our dissection location was too medial. We encountered the left common iliac vein, which, fortunately, was not injured. However, this anatomic landmark did help us redirect our dissection. The third is a 77-year-old female with vault eversion, her pre-operative MRdef study demonstrated a loop of colon in front of the promontory. During the rASC procedure, the colon was identified to be directly over the promontory, which we gently retracted and dissected to adequately expose the anterior longitudinal ligament underneath. Finally, our last patient was a 69-year-old female with vault prolapse with a history of a back fusion. Unfortunately, no operative notes to confirm the location of her hardware were available. Discussion with our orthopedic colleagues reviewing her plain films concluded that the anterior longitudinal ligament would likely not be intact in this area. This impression was reinforced by the MRdef, which revealed artifact from the hardware directly over the promontory. In such a scenario, one could consider a lower presacral anchoring site or an alternative fixation technique such as the peritoneal colpopexy, as previously described [2]. CONCLUSIONS: Knowledge of the presacral anatomy, and the potential variants, is critical to safely perform a rASC. MRdef is an important tool in both defining the pelvic floor support defects prior to surgery, but also in highlighting difficult anatomy at the sacral promontory to assist with operative planning. Reference Lee D, Zimmern PE. Abdominal mesh sacrocolpopexy without promontory fixation: initial results of the peritoneocolpopexy technique. J Urol. 2015 Jun;193(6):2089-93. doi: 10.1016/j.juro.2015.01.085 Source of Funding: N/A © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e565 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Colby P. Souders More articles by this author Ramy Goueli More articles by this author Hersh Trivedi More articles by this author Gaurav Khatri More articles by this author Philippe E. Zimmern More articles by this author Expand All Advertisement PDF DownloadLoading ...

P147 Venous fibrosis and stenosis in IgG4-related disease

Abstract Background/Aims IgG4-related disease (IgG4-RD) is a multi-system fibro-inflammatory disease. Common presentations involve salivary and lacrimal glands, orbital disease, autoimmune pancreatitis, retroperitoneal fibrosis and tubulointerstitial nephritis. The main histopathological features are a dense, polyclonal, lymphoplasmacytic infiltrate rich in IgG4+ plasma cells, storiform fibrosis and obliterative phlebitis. Cases of retroperitoneal fibrosis resulting in venous compression with DVT are well described, however to our knowledge venous fibrosis and stenosis confirmed with IVUS in IgG4-RD RPF has never been described. Methods An 82-year-old lady presented with bilateral lower leg oedema. She had a past diagnosis of IgG4 disease made on the basis of retroperitoneal fibrosis (confirmed on PET-CT), raised serum IgG4 levels (IgG4 2.38; normal 0.04-0.86 g/l) a supportive tissue biopsy (fibro-lymphocytic tissue with non-diagnostic IgG4 plasma cells) and raised inflammatory markers (CRP 104, ESR 120). Disease responded well to prednisolone and azathioprine, resulting in regression of RPF. She presented with left leg pitting oedema 4 months after presentation which progressed to chronic leg venous ulceration. D-dimer testing, albumin, liver function, and renal function tests were normal. There were no signs of lymphoedema. Venous Doppler studies of the left lower leg showed a patent and compressible left common femoral, superficial femoral and popliteal vein excluding a DVT and Baker’s cyst. A repeat CT pelvis showed no compressive mass. An intravascular ultrasound showed that the wall of the IVC was stiff and of dampened amplitude with respiratory motion. There was also increased echogenicity of the left common and external iliac vein wall with significant stenosis of the distal left common iliac vein and the external iliac veins. On the right side, there was increased echogenicity of the right common iliac vein, but the lumen was well preserved. Results These findings indicated fibrosis of the IVC wall and left common iliac vein with resulting venous stenosis. The patient underwent bilateral iliac vein stenting with improvement of leg swelling and eventual healing of the venous ulcer. Conclusion This case demonstrates that venous fibrosis and stenosis may occur in the absence of compressive lesions leading to leg swelling. Further diagnostic information may be identified by IVUS and radiological intervention with venous stents may be required. Disclosure R. Baslas: None. D. Condurache: None. D. Greenstein: None. L. Patrone: None. S. Hamdulay: None.

May-Thurner Syndrome in Pregnancy: A Case Report

May-Thurner Syndrome, left iliac vein compression by the right iliac artery, is a congenital permissive lesion that requires an additional insult prior to the onset of symptoms. We present a case of a 31-year-old gravida 1 para 0 at 28.6 weeks who presented to the emergency room with a 2-month history of progressive lower left leg swelling since 21.2 weeks’ gestation. The patient endorsed incidence of domestic violence at 17 weeks’ gestation. The patient had a twin sister who was also pregnant and had not experienced these symptoms. Physical exam revealed 3+ pitting edema in the left lower extremity from ankle to groin. There was left calf tenderness with negative Homan’s sign bilaterally. Overall finding on magnetic resonance angiography revealed severe compression of the upper left common iliac vein and lower inferior vena cava by gravid uterus. Conservative management and anticoagulation is instrumental in preventing veno-thromboembolic events in pregnancies complicated by MTS.

Importance of Surgical Order for Minimizing Vascular Injury During the L5-S1 Approach in Multilevel Oblique Lateral Interbody Fusion Surgery.

In oblique lateral interbody fusion (OLIF) surgery at the L5-S1 level (OLIF51), anatomical complexity and the possibility of vascular injury during retraction of the common iliac vein (CIV) make the surgery challenging. We radiologically evaluated patients who underwent OLIF surgery to determine approaches that can make OLIF51 surgery easier during multilevel OLIF. We retrospectively analyzed 275 consecutive patients who underwent OLIF surgery between September 2014 and December 2019. The distance between the left and right CIVs (dCIV) was measured using an axial image at the L5 lower endplate level, and the height of the iliocaval junction (hCIV) was measured from the L5 lower endplate to the iliocaval junction in the sagittal image. The sum of anterior disc height of each level (sADH) was calculated. Eighty-two patients (33 males and 49 females) were enrolled. The number of three- (L2-3-4-5), two- (L3-4-5), and one-level (L4-5) fusions was 13, 21, and 48, respectively. Changes between the pre- and postoperative sADH, dCIV, and hCIV values were 17.1±4.7, 7.7±3.5, and 13.1±4.7 mm in three-level fusion; 10.6±4.1, 5.6±3.7, and 7.0±3.1 in two-level fusion; and 4.3±2.5, 3.3±2.7, and 3.0±2.0 mm in one-level fusion, respectively. As the number of surgical levels increased, the changes in sADH, dCIV, and hCIV significantly increased. The dCIV and hCIV values increased when the upper segment underwent surgery before OLIF51 during multilevel OLIF.

Left lower limb deep venous thrombosis, May-Thurner syndrome and endovascular management.

Objectives:To determine the prevalence of May-Thurner syndrome (MTS) in left lower limb deep venous thrombosis (DVT) cases and to analyze the outcome of endovascular intervention in these patients.Methods:A record-based descriptive study was carried out in Radiology Department, King Fahad Military Medical Complex, Dhahran, Saudi Arabia, including patients who underwent lower limb duplex ultrasounds between January 2015-2021. Patients with bilateral DVTs, known pelvic masses, and pelvic surgeries were excluded. All patients positive for DVTs were identified and further imaging was reviewed. Left common iliac vein compression of 50% or more on computed tomography (CT) was considered positive for MTS. Endovascular interventions (venoplasty alone or with stenting) were evaluated and success recorded by observing patency of vein on follow-up imaging or improvement of symptoms on follow-up visits.Results:Of 182 patients with left lower limb duplex studies, 51 patients were positive for DVTs. A total of 37 patients had CTs and 21 patients had MTS (17 females, 3 males). A total of 15 patients underwent endovascular interventions, 2 patients had venoplasties alone (one successful) and 13 patients had venoplasties with stenting (10 successful).Conclusion:Patients with MTS as cause of DVT may benefit from early endovascular intervention.

Double Inferior Vena Cava with Major Predominance of the Left Inferior Vena Cava: A Cadaver Case Report.

We encountered a case of a double inferior vena cava with major predominance of the left inferior vena cava during an anatomical dissection course for medical students in 2015. The right inferior vena cava (normal inferior vena cava) was 2.0 mm wide, and the left inferior vena cava was 23.2 mm wide. The fine right inferior vena cava began at the right common iliac vein, ascended along the right side of the abdominal aorta, and then joined the left inferior vena cava at the level of the lower margin of the first lumbar vertebra. The dominant left inferior vena cava started from the left common iliac vein and ascended along the left side of the abdominal aorta. Most patients with a double inferior vena cava are asymptomatic, and these variants are incidentally detected by computed tomography or magnetic resonance imaging. Their presence may have significant implications for surgery, particularly abdominal surgery in patients with paraaortic lymphadenopathy and in those undergoing laparoscopic radical nephrectomy or inferior vena cava filter placement. We herein discuss the embryology of a double inferior vena cava based on detailed anatomical data of the variations of a double inferior vena cava, including those that require clinical attention.

A Rare Variation of Retroaortic Left Renal Vein Draining into Left Common Iliac Vein

A 24-year-old woman without underlying disease presented with right lower abdominal pain for a day. The patient’s clinical symptoms were suspected acute appendicitis and underwent multidetector computed tomography. There is diffuse enlarged appendix with diffuse wall thickening and enhancement as well as minimal surrounding fat stranding. Mild thickened peritoneum is also observed. There is no fluid collection or free air. The radiologist diagnosed acute appendicitis without complication. Incidentally, the patient was found a rare anatomical variation of the retroaortic left renal vein draining into left common iliac vein. Patient underwent appendectomy. We would like to present a characteristic imaging of the renal vein variations.&#x0D;

C62. May-Thurner syndrome, a diagnosis and endovascular treatment in adult women with no risk factor: a case report and literature review

Abstract May-Thurner syndrome (MTS) is a venous compression syndrome in which the left common iliac vein (LCIV) is compressed between the lower lumbar spine and the right common iliac artery (RCIA). This syndrome is suspected when a patient presents with recurrent or chronic venous insufficiency (CVI) or deep vein thrombosis (DVT) on his/her left lower extremity; although MTS’ clinical presentation varies. A history of recurrent left lower extremity DVT and symptoms associated with chronic venous hypertension, including varicosities, venous ulcers, lower limb swelling, and pain in the inguinal, calf, or upper leg regions suggests MTS diagnosis. We present a case report and conduct a literature review on a patient presenting with painful, numb, and swollen left leg since three months before admission. Intermittent claudication was found. Doppler ultrasonography confirmed no thrombus, yet suggested that the RCIA compressed the LCIV. Doppler’s finding was confirmed using computed tomography (CT) scan, and RCIA compression seemed to cause an obstruction. MTS diagnosis is often missed in patients with lower limb pain because the block is not caused by a thrombus and a clinician often misses to conduct Doppler examination on the iliac artery/vein. This study highlights the importance of considering MTS in a patient with left lower limb pain, and chronic DVT which is unresponsive to pharmacological treatment, hence, endovascular treatment may be warranted.

C62. May-Thurner syndrome, a diagnosis and endovascular treatment in adult women with no risk factor: a case report and literature review

Abstract May-Thurner syndrome (MTS) is a venous compression syndrome in which the left common iliac vein (LCIV) is compressed between the lower lumbar spine and the right common iliac artery (RCIA). This syndrome is suspected when a patient presents with recurrent or chronic venous insufficiency (CVI) or deep vein thrombosis (DVT) on his/her left lower extremity; although MTS’ clinical presentation varies. A history of recurrent left lower extremity DVT and symptoms associated with chronic venous hypertension, including varicosities, venous ulcers, lower limb swelling, and pain in the inguinal, calf, or upper leg regions suggests MTS diagnosis. We present a case report and conduct a literature review on a patient presenting with painful, numb, and swollen left leg since three months before admission. Intermittent claudication was found. Doppler ultrasonography confirmed no thrombus, yet suggested that the RCIA compressed the LCIV. Doppler’s finding was confirmed using computed tomography (CT) scan, and RCIA compression seemed to cause an obstruction. MTS diagnosis is often missed in patients with lower limb pain because the block is not caused by a thrombus and a clinician often misses to conduct Doppler examination on the iliac artery/vein. This study highlights the importance of considering MTS in a patient with left lower limb pain, and chronic DVT which is unresponsive to pharmacological treatment, hence, endovascular treatment may be warranted.

Abstract 17133: Complete Inferior Vena Cava Thrombosis In A Sickle Cell Patient With Suspected May Thurner Syndrome

Case Presentation: 19 year old woman with sickle cell anemia and nephrotic syndrome presented with leg and back pain. While treated for vaso-occlusive crisis, patient developed dyspnea and chest pain. She underwent CT chest which revealed a right lower lobe pulmonary embolism. The patient was started on anticoagulation. Her transthoracic echocardiography revealed normal right heart function but nearly occlusive inferior vena cava (IVC) thrombus just distal to the right atrium. Subsequently a CT venogram demonstrated extensive thrombus from the left external iliac vein to the right atrium as well as compression of the left common iliac vein. Multidisciplinary discussion was performed to discuss options including medical therapy, surgical removal, or catheter-based removal. Given concern for further pulmonary embolization, patient underwent catheter based thrombus removal. A 26 french access was obtained in the right internal jugular vein and a 17 french access was obtained in the right femoral vein. Using the Angiovac system, mechanical thrombectomy was performed in the IVC. The angiovac system is a 24 french suction catheter with filtration and reperfusion through the right femoral vein. Limited thrombus removal was achieved. Next,14 french left femoral vein access was obtained and the Inari Clottriever device was used to mechanically score and remove a significant amount of thrombus (Figure 1). Post removal angiography revealed a patent IVC with minimal residual thrombus. Discussion: IVC thrombosis is a rare presentation of venous thromboembolism (VTE). This patient had multiple reasons for VTE including nephrotic syndrome and likely May Thurner Syndrome (MTS). MTS is an underdiagnosed entity resulting in mechanical compression of the left iliac vein in upto 50% of patients presenting with left lower extremity VTE. While proximal extension of thrombus is rare as seen in this case, high clinical suspicion is warranted for accurate diagnosis and treatment.

Immediate postprocedure anticoagulation with factor Xa inhibitors of venous stents for nonthrombotic venous lesions does not increase stent patency

BackgroundMany clinicians will prescribe anticoagulation therapy for patients after iliac vein stenting to prevent early or late stent thrombosis. At present, it is unknown whether therapeutic anticoagulation has any effect on stent patency. Thus, we assessed the role of short-term anticoagulation on iliac vein stent patency in patients with nonthrombotic iliac vein lesions (NIVLs). MethodsWe performed a retrospective medical record review of all iliac vein stents placed for NIVLs at the Center for Vascular Medicine from January 2018 to December 2019. We compared the stent patency in the two groups. The anticoagulation (AC) group had received rivaroxaban or apixaban postoperatively for a minimum of 90 days and were compared with a group that had received no postoperative anticoagulation (NAC). Stent patency was assessed using transabdominal ultrasound at 3, 6, 12, 18, 24, and 30 months. At the discretion of the treating physician, the patients who demonstrated thrombus layering on surveillance ultrasound scanning continued rivaroxaban or apixaban until thrombus resolution was observed. The demographics and stent location, diameter, and length were assessed. Stent patency was analyzed using life table analyses. Differences in stent patency were analyzed using GraphPad Prism, version 8, statistical software (GraphPad Software Inc, La Jolla, Calif) and the log-rank (Mantel-Cox) test. ResultsThe number of patients and stents in each group were as follows: AC group, 299 patients and 308 stents; and NAC group, 77 patients and 90 stents. The average age was 52.24 ± 13.44 years and 55.63 ± 14.49 years in the AC and NAC groups, respectively (P ≤ .065). Women constituted 76% of the patients in the AC group and 72% in the NAC group. The average stent diameter and length for the AC group was 20 ± 2 mm and 77 ± 13 mm and for the NAC group was 19 ± 2 mm and 82 ± 9 mm, respectively. The stents had been placed in the right common iliac vein, bilaterally, or left common iliac vein territory in 15%, 3%, and 82% in the AC group and 18%, 2%, and 80% in the NAC group, respectively. The cumulative stent patency at 30 months was 98.7% and 94.6% for the NAC and AC groups, respectively (P ≤ .83). All the stents placed were Wallstents (Boston Scientific, Marlborough, Mass). A total of eight insertion site thromboses occurred that did not affect stent patency: five in the AC group (1.6%) and three in the NAC group (4.5%; P = .15). In addition, 19 patients demonstrated evidence of thrombus layering, with 6 receiving extended anticoagulation. ConclusionsOur data indicate that perioperative stent thrombosis in patients with NIVLs is uncommon. Thus, anticoagulation for perioperative stent thrombosis prophylaxis is not necessary. Anticoagulation should only be used for patients with insertion site thromboses and should be considered if thrombus layering is observed on surveillance scanning.

May-Thurner syndrome successfully managed with an endovascular stent: A case report

May-Thurner Syndrome (MTS) or iliac vein compression syndrome is caused by compression of the left common iliac vein by the right common iliac artery. The incidence rate of MTS is unknown. In an autopsy study in the early twentieth century, the incidence ranges from 22 to 32%. MTS-related deep venous thrombosis accounts for only 2%-3% of all lower limb DVTs. The patient may present with leg swelling, varicosities, deep venous thrombosis, chronic venous stasis ulcers, or more serious complications, such as pulmonary embolism. Iliac vein compression can be assessed with Computed Tomography (CT) and iliac venography. The goal of treatment is to reduce symptoms and the risk of complications. Stent placement is an alternative method to a direct surgical approach. We present 2 cases of MTS that were treated with stent placement.

The Case of the Elusive Oscillating Bullet Embolus and Its Ultimate Jailing

<h3>Introduction and Objective</h3> Intravascular missile embolus is a rare, but potentially morbid, result of penetrating trauma. Herein, we present the case of a 43-year-old man with a single ballistic injury to the left hip, resulting in an isolated injury to the iliac wing, entry into the lumen of the left common iliac vein, and an embolic course to the atriocaval junction. The missile subsequently and repeatedly migrated to a variety of locations in the venous system. The oscillating behavior of the bullet and its ultimate endovascular management demonstrates a novel scenario which may be applicable in the treatment of future patients. <h3>Methods and Case Management</h3> A 43-year-old man, presented to our department trauma center with an isolated gunshot wound to the left hip. Initial plain films of the pelvis and abdomen were obtained revealing the absence of a radiopaque ballistic fragment. A plain film of the chest and contrasted cross-sectional imaging soon after revealed the bullet at the atriocaval junction. There were no observed viscous or solid organ injury. Additional imaging studies, temporally spaced, demonstrated the fragment that was then situated in the right pelvis (Figure 1a, 1b, 1c). The ballistic fragment continued to oscillate from the atriocaval junction to the right pelvis as demonstrated on serial plain films. In a hybrid operating theater with fluoroscopic capability, venogram revealed the bullet to be lodged in the right internal iliac vein (Figure 1c). After unsuccessful attempts at snaring the missile, the decision was made to stent across the ostia of the internal iliac vein and trap the missile in place. Sizing was performed using intravascular ultrasound and an 18 × 40 mm Wallstent was successfully deployed to jail the bullet (Figure 1d,1e). <h3>Results</h3> Completion venography demonstrated good result with the bullet excluded. The patient was discharged home on post-operative day two at follow-up 4 months later, he was found to be asymptomatic and doing well. The bullet remains in the right hemipelvis on subsequent imaging studies. <h3>Conclusion</h3> While the occurrence of bullet emboli has not become common enough to have standardized management, the option to trap intravascular ballistic fragments with an endovascular approach, may be a safe alternative compared to more invasive open intervention.

The diagnostic role of IVUS in pelvic venous disease

The two main mechanisms for pelvic venous disease (PeVD) are reflux of ovarian vein and obstruction of left common iliac or left renal vein. Some patients have a combination of the two. Adequate assessment of the location and degree of stenosis and delineation of venous anatomy are the key elements in the success of interventions to treat chronic obstructions causing PeVD. While venography is more accessible and less expensive to perform than intravascular ultrasound (IVUS), an increasing number of studies have demonstrated that IVUS is significantly more sensitive than venography in identifying stenotic lesions and real-time anatomical alterations of the affected venous segments. In this paper, we discuss the derived information and the clinical applications of IVUS during such interventions. The definitive diagnosis of PeVD can be achieved with venography combined with IVUS to evaluate for obstructive lesions in the iliac veins and compression of the left renal vein. Venography has poor sensitivity and specificity in the detection of venous stenosis. However, IVUS can detect fine intraluminal trabeculae and outside compression that can be missed with standard multiplanar venography. The IVUS can confidently confirm the persistent venous stenosis regardless of the hemodynamical alterations of venous pressure, as well. Moreover, it is possible to precisely measure the diameter of ovarian vein with IVUS. This may be helpful to decide about the diameter of the coils or the plugs needed to avoid migration. In conclusion, IVUS enables us to accurately evaluate the underlying cause of PeVD and apply a patient"s tailored treatment on table.

Clinical Implications of Anatomic Variations of the Presacral Space

<h3>Study Objective</h3> To describe the presacral space and the spatial relationship between key anatomic landmarks, demonstrate anatomic variations in the presacral space, and discuss the clinical implications as they relate to minimally invasive surgery. <h3>Design</h3> Video description of key landmarks found in the presacral space, the fundamental steps of a presacral neurectomy, cases with anatomic variations of the presacral space, and clinical implications. Patients provided consent for the video and publication. This video with no identifying patient data was exempt from Institutional Review Boards Approval. <h3>Setting</h3> Video laparoscopy was performed. <h3>Patients or Participants</h3> We present patients with anatomic variations of the presacral space as well as cases demonstrating the clinical implications. <h3>Interventions</h3> Once the presacral space is entered, there are key landmarks to note. In a presacral neurectomy, the peritoneum overlying the sacral promontory is elevated and a small opening is made. The peritoneum is incised horizontally and vertically, and the opening is extended cephalad to the aortic bifurcation. Retroperitoneal lymphatic tissue including the nerve fibers of the hypogastric plexus are skeletonized, desiccated, and excised. All of the nerve fibers within the boundaries of the Triangle of Cotte are removed, including those entering the area from under the common iliac arteries and over the left common iliac vein. <h3>Measurements and Main Results</h3> The procedures that warrant dissection in this area include presacral neurectomy, sacropexy, lymphadenectomy, and certain cases of bowel mobilization. The clinical implications of anatomic variations are important to consider prior to abdominal entry and dissection of the presacral space to decrease the risk of surgical complications<b>.</b> <h3>Conclusion</h3> The anatomic pattern of the presacral space is variable, major vessels may deviate significantly from their expected positions, and prior to entering the space, surgeons should be careful to have full exposure.