Can Loupe magnification be a viable alternative to Operative Microscope magnification for vascular anastomosis in reconstructive surgery? A systematic review and meta-analysis.

PURPOSE: The aim of this study is to compare the outcomes of vascular anastomosis using loupes magnification versus operative microscope magnification in reconstructive surgery. METHODS: We performed a systematic review of MEDLINE (via PubMed), Scopus and Cochrane Library database according to the PRISMA guidelines. Comparative studies between the two techniques and single arm studies reporting on loupes reconstruction were included. Random-effects model meta-analyses were performed. RESULTS: Twelve studies, reporting a total of 3908 of flaps, 3409 of which were performed under loupes magnification and 499 under the operative microscope magnification were selected for analysis. No statistically significant differences were observed regarding total flap loss and vascular complication between the two arms. In the Loupes group the rate of total flap loss was 2.65% (95% CI: 1.15-4.63) and the rate of vascular complications 4.49% (95% CI: 2.58-6.84). CONCLUSION: Loupes magnification under circumstances can provide a safe and effective alternative to microvascular reconstruction in reconstructive surgery. With respect to flap failure and vascular complication rates, there appear to be no statistically significant differences between the anastomoses conducted under Loupes magnification and the standard operative microscope.

3D printing: a useful tool for safe clinical practice in children with complex vasculature.

BACKGROUND: 3D printing has been used in different medical contexts, although it is underutilised in paediatrics. We present the first use of 3D printing in the management of three paediatric patients with complex renovascular disease. METHODS: Patient-specific 3D models were produced from conventional 2D imaging and manufactured using 3D polyjet printing technology. All three patients had different underlying pathologies, but all underwent multiple endovascular interventions (renal artery balloon angioplasty) prior to 3D printing and subsequent vascular surgery. The models were verified by an expert radiologist and then presented to the multidisciplinary team to aid with surgical planning. RESULTS: Following evaluation of the 3D-printed models, all patients underwent successful uni/bilateral renal auto-transplants and aortic bypass surgery. The 3D models allowed more detailed preoperative discussions and more focused planning of surgical approach, therefore enhancing safer surgical planning. It influenced clinical decision-making and shortened general anaesthetic time. The families and the patients reported that they had a significantly improved understanding of the patient's condition and had more confidence in understanding proposed surgical intervention, thereby contributing to obtaining good-quality informed consent. CONCLUSION: 3D printing has a great potential to improve both surgical safety and decision-making as well as patient understanding in the field of paediatrics and may be considered in wider surgical areas.

Comparison of manual compression, Z-stitch, and suture-mediated vascular closure device techniques in dogs undergoing percutaneous transvenous intervention.

INTRODUCTION/OBJECTIVES: Manual compression has been standard of care for maintaining hemostasis after percutaneous endovascular intervention, but can be time-consuming and associated with vascular complications. Alternative closure methods include the figure-of-eight suture (Z-stitch) and vascular closure device (VCD) techniques. We hypothesized that compared to manual compression, Z-stitch and VCD would significantly reduce time-to-hemostasis after transvenous access, and the proportion of dogs with vascular patency would not differ significantly among treatments. ANIMALS: Forty-six client-owned dogs undergoing percutaneous transvenous interventional procedures. MATERIALS AND METHODS: Dogs with vessel diameter <5 mm were randomized to undergo manual compression or Z-stitch, while those with vessel diameter ≥5 mm were randomized to undergo manual compression, Z-stitch, or VCD. Time-to-hemostasis, bleeding scores, presence of vascular patency one day and two to three months post-procedure, and complications were recorded. Data are presented as median (95% confidence interval). RESULTS: In all 46 dogs, the right external jugular vein was used. Time-to-hemostasis was significantly shorter in the Z-stitch (2.1 [1.8-2.9] minutes) compared to VCD (8.6 [6.1-11.8] minutes; P<0.001) and manual compression (10.0 [10.0-20.0] minutes; P<0.001) groups. Time-to-hemostasis was significantly shorter in the VCD vs. manual compression (P=0.027) group. Bleeding scores were significantly greater at 5 and 10 min (P<0.001 and 0.013, respectively) in manual compression, compared to Z-stitch group. There was no difference in the proportion of dogs with vascular patency between groups (P=0.59). CONCLUSIONS: Z-stitch and VCD are effective venous hemostasis methods after percutaneous transvenous intervention, with Z-stitch providing the most rapid time-to-hemostasis. Both Z-stitch and VCD techniques have low complication rates and effectively maintain vascular patency.

Frugal indigenous vessel loop made from a surgical glove.

We report a simple cost effective alternative to commercially available vessel loops made from sterilized surgical gloves for retraction of vital structures during vascular trauma, micro-vascular, micro-neural surgery.

In-stent restenosis and stent compression following stenting for chronic iliofemoral venous obstruction.

OBJECTIVE: In-stent restenosis (ISR) and stent compression (SC) are problems encountered after stenting for chronic iliofemoral venous obstruction that are responsible for a majority of reinterventions. However, characteristics of ISR and SC, in addition to outcomes after reintervention, have not been explored in detail and represent the focus of this study. METHODS: A retrospective analysis of contemporaneously entered electronic medical record data on 578 limbs/patients with initial unilateral iliofemoral venous stents placed from 2014 to 2018 was performed. ISR was estimated from stent and flow channel diameters measured using duplex ultrasound. SC was estimated from rated stent diameter and actual stent diameter on duplex ultrasound. Characteristics evaluated included onset of ISR/SC after stent placement and progression over time. Analysis was performed to evaluate risk factors for the development of ISR and SC. Outcomes after reintervention for ISR/SC were also appraised. RESULTS: A total of 578 limbs underwent stenting for stenotic lesions (nonthrombotic iliac vein lesion/post-thrombotic syndrome). ISR was noted in 27% of limbs on post-intervention day 1. The prevalence of ISR increased to 74% by 3 months and stabilized thereafter. SC was noted in 80% of limbs on day 1 and plateaued. Of the variables evaluated as potential risk factors for ISR, intravascular ultrasound determined stent inflow luminal area and shear rate were found to be significant. For SC, asymmetric stent sizing was a significant risk factor. Over a median follow-up of 24 months, 95 of 578 (16.4%) limbs underwent reintervention for ISR, SC, or a combination. The median time to reintervention was 11 months. There was no statistically significant difference in the degree of ISR/SC among patients who underwent reintervention vs those who did not (P > .05). However, there was a statistically significant difference in the grade of swelling (P = .006) and visual analog scale pain scores (P < .0001) between those who underwent reintervention and those who did not. Primary, primary assisted, and secondary patencies at 60 months were 70%, 98%, and 84% after reintervention for ISR and 70%, 99%, and 84% for SC, respectively. CONCLUSIONS: Although ISR and SC are both common after stenting for chronic iliofemoral venous obstruction, neither are relentlessly progressive. Indication for reintervention must be a recurrence of symptoms with impairment of quality of life and not the percentage of ISR or degree of SC. After reintervention good outcomes can be expected both in terms of clinical improvement and stent patency. Further study of the impact of shear rate on stent flow is required to help reduce the incidence of ISR.

Long-term outcome of dedicated venous stents in management of chronic iliofemoral obstruction.

OBJECTIVE: To study the long-term outcomes in patients with occlusive Iliofemoral chronic venous insufficiency (CVI) of benign etiology treated by dedicated venous stents (Zilver Vena stents; Cook, Bloomington, Ind) placed at a single center. METHODS: We performed retrospective analysis of prospectively collected data from 58 patients with symptomatic benign lower limb CVI during the period from January 2013 to October 2020. Patients underwent recanalization using Zilver Vena stents at Ain Shams University hospitals. We excluded patients requiring stenting after intervention for acute deep venous thrombosis, CVI due to malignancy or vascular malformations, previous ipsilateral venous interventions, or CVI due to nonobstructive pathology (reflux). Patients were clinically classified at enrollment by the clinical, etiology, anatomy, pathology class, venous disability score, and Villalta score. Primary, assisted primary, and secondary stent patency were assessed. Patients were followed clinically and by duplex, at 1, 3, 6, 12 months and annually for 5 years. RESULTS: There were 31 males and 27 females, with ages ranging between 25 and 60 years (mean, 43.84 years). All patients had post-thrombotic syndrome with a mean Villalta score of 16.8 (range, 10-31). Patients were treated with dedicated venous stents and had a median follow-up of 60 months. The median venous disability score was 3 at the start of the study with a significant decrease to 1 at 5-year follow-up (P < .001). Twelve-month primary patency, assisted primary patency, and secondary patency were 91.4%, 96.6%, and 98.3%, respectively. At the 5-year follow-up, primary patency was 60.3%, assisted primary patency 65.5%, and secondary patency 81%. There were no instances of stent fracture, migration, or structural deformities. CONCLUSIONS: Treating iliofemoral venous occlusive disease with a dedicated venous stent is an excellent choice for patients with occlusive post-thrombotic syndrome. The technique has good 1-year and 5-year patency and is associated with significant clinical improvement and few complications.

Iliac vein stenting is safe when performed in an office based laboratory setting.

BACKGROUND: Venous stenting for iliac vein outflow obstruction is associated with excellent long-term stent patency and symptom resolution. However, the safety of iliac vein stenting performed in an office-based laboratory (OBL) setting is not well-defined. The purpose of our investigation was to determine the safety profile of iliac vein stenting in an OBL setting. METHODS: Data were prospectively collected in the Center for Vascular Medicine electronic medical record system (NextGen Healthcare Information System, Irvine, Calif) and retrospectively analyzed. Standardized patient safety and sedation protocols were used in accordance with the accreditation standards of the Joint Commission for Accreditation of Hospital Organizations for office-based surgery centers. Patient consultations, interventions, and follow-up at 1 to 6 weeks were included in the present analysis. All the patients had received moderate sedation during their procedure. Complications requiring hospitalization were classified as major complications. Minor complications consisted of bleeding, hematoma, vasovagal response, in-stent thrombosis resulting in complete occlusion of the iliac vein stent, an allergic reaction, hematemesis, hypotension, pelvic discomfort, and pseudoaneurysm. RESULTS: Between January 2015 and January 2019, 1223 iliac vein stents were placed in 1104 patients (23.7% male; 76.3% female). A total of 90 minor complications (7.36%) and 5 major complications (0.41%) were observed. The major complications included the following: one allergic reaction, one episode of atrial fibrillation, one episode of supraventricular tachycardia, one episode of chest pain, and one case of acute stent occlusion. The minor complications were primarily insertion site hematomas. No complications were related to sedation or acute renal failure. No patient died. CONCLUSIONS: Major complications were rare after iliac vein stenting in an OBL setting. Minor complications were primarily insertion site hematomas, which did not require inpatient hospitalization. Our analysis has shown that iliac vein stenting in an OBL setting is a safe and well-tolerated procedure.

Analysis of spin in vascular surgery randomized controlled trials with nonsignificant outcomes.

OBJECTIVE: Spin is the manipulation of language that distorts the interpretation of objective findings. The purpose of this study is to describe the characteristics of spin found in statistically nonsignificant randomized controlled trials (RCT) comparing carotid endarterectomy with carotid artery stenting for carotid artery stenosis (CS), and endovascular repair with open repair (OR) for abdominal aortic aneurysms (AAA). METHODS: A search of MEDLINE, EMBASE, and the Cochrane Controlled Register of Trials was performed in June 2020 for studies published describing AAA or CS. All phase III RCTs with nonsignificant primary outcomes comparing open repair with endovascular repair or carotid endarterectomy to carotid artery stenting were included. Studies were appraised for the characteristics and severity of spin using a validated tool. Binary logistic regression was performed to assess the association of spin grade to (1) funding source (commercial vs noncommercial) and (2) the publishing journal's impact factor. RESULTS: Thirty-one of 355 articles captured were included for analysis. Spin was identified in 9 abstracts (9/18) and 13 main texts (13/18) of AAA articles and 7 abstracts (7/13) and 10 main texts (10/13) of CS articles. For both AAA and CS articles, spin was most commonly found in the discussion section, with the most commonly used strategy being the interpretation of statistically nonsignificant primary results to show treatment equivalence or rule out adverse treatment effects. Increasing journal impact factor was associated with a statistically significant lower likelihood of spin in the study title or abstract conclusion (ß odds ratio, 0.96; 95% confidence interval, 0.94-0.98; P < .01); no significant association could be found with funding source (ß odds ratio, 1.33; 95% confidence interval, 0.30-5.92; P = .71). CONCLUSIONS: A large proportion of statistically nonsignificant RCTs contain interpretations that are inconsistent with their results. These findings should prompt authors and readers to appraise study findings independently and to limit the use of spin in study interpretations.

Endovascular Release of a 50-Year-Old Adams-Deweese IVC Clip to Facilitate Percutaneous Repair of Mitral Valve Regurgitation.

Percutaneous mitral valve (MV) repair using MitraClip requires large-caliber venous access. We describe a patient with a ligated inferior vena cava due to an Adams-DeWeese clip placed 50 years prior, who had progressive shortness of breath and lower extremity symptoms secondary to severe mitral regurgitation and chronic iliocaval deep venous thrombosis. Due to comorbidities, MitraClip was recommended over surgery for MV repair. Caval luminal gain was required to facilitate endovascular access for the MitraClip system. Stent-mediated release of the inferior vena cava clip allowed successful passage of the delivery sheath from the common femoral vein to MV and subsequent valve repair.

Utility of the 50% stenosis criterion for patients undergoing stenting for chronic iliofemoral venous obstruction.

OBJECTIVE: The criterion for venous stenting in symptomatic chronic iliofemoral venous obstruction has been the arbitrary use of stenosis of ≥50%. In the present study, we evaluated the intravascular ultrasound (IVUS)-determined degree of stenosis in patients who had undergone stenting for quality of life (QOL)-impairing symptoms and assessed the utility of the 50% stenosis cutoff. METHODS: A retrospective review of contemporaneously entered electronic medical record data from 480 continuous patients (480 limbs) with initial iliofemoral stents placed (2014 to 2017) for symptomatic chronic iliofemoral venous obstruction impairing their QOL was performed. The IVUS-determined normal minimal luminal areas for the common femoral vein (125 mm), external iliac vein (150 mm), and common iliac vein (200 mm) were used to group limbs as having <50% (low-grade stenosis [LGS]) or ≥50% (high-grade stenosis [HGS]) stenosis. The variables compared included the visual analog scale (VAS) for pain score, venous clinical severity score (VCSS; range, 0-27), ulcer healing, supine foot venous pressures, QOL (20-item chronic venous disease QOL questionnaire), and stent patency. A composite chronic venous insufficiency score (CCVIS) incorporating the VAS score, VCSS, and CIVIQ-20 score for predicting improvement after stenting was evaluated. RESULTS: Of the 480 limbs, 283 and 197 were in the LGS and HGS groups, respectively. A preponderance of women, left laterality, and post-thrombotic syndrome were noted in both groups. At baseline, although no difference was found in the VAS for pain score between groups, the LGS group had a higher VCSS than did the HGS group (P = .05). The baseline median supine foot venous pressure was 15 and 14 mm Hg in the LGS and HGS groups, respectively (P = .17). At 24 months after stenting, the mean VCSS had improved from 6.3 to 4.4 (P < .0001) and from 5.7 to 3.7 (P < .0001) in the LGS and HGS groups, respectively, without significant differences between the two groups (P = .07). A greater prevalence of ulcers was found in the LGS group (18% vs 11%; P = .04), with no differences in healing (P = .41) or recurrence rates (P = .36). The QOL scores had improved in both groups (LGS, from 58 to 37 [P < .0001]; HGS, from 61 to 35 [P < .0001]), without differences between the two groups (P > .3). No significant differences in stent patency or reinterventions rates were found. A baseline CCVIS of ≥84.5, ≥86.9, or ≥105.3 was needed for a 30-, 40-, and 50-point improvement in most limbs after stenting. CONCLUSIONS: The degree of IVUS-determined iliofemoral venous stenosis did not appear to affect the initial clinical presentation, CEAP (clinical, etiologic, anatomic, pathophysiologic) clinical class, supine foot venous pressure, clinical improvement, QOL improvement, stent patency, or reintervention rates after stenting. Patients presenting with QOL-impairing symptoms in whom conservative treatment has failed merit consideration of correction of their obstruction even if the degree of stenosis is <50%. The use of a CCVIS might be helpful but requires further study.

Use of 8Fr angio-seal for closure of femoral arteriotomy following use of 8Fr and 9Fr sheaths in patients undergoing mechanical thrombectomy for acute ischaemic stroke.

BACKGROUND: Little is known about the safety of off-label use of an 8Fr Angio-Seal VIP for large-bore arteriotomies in patients treated with mechanical thrombectomy (MT) and intravenous thrombolysis (IVT) for acute ischaemic stroke (AIS). We aimed to identify differences in the groin complication rate using an 8Fr Angio-Seal VIP for common femoral arteriotomy closures following the use of 8Fr and 9Fr sheaths. METHODS: All AIS patients who underwent MT at our tertiary neuroscience unit between January 2018 and March 2020 were retrospectively reviewed. RESULTS: 161 patients were included in the study, of whom 56 and 105 patients underwent an arteriotomy using an 8Fr sheath (36 of them receiving IVT) and a 9Fr sheath (57 of them receiving IVT). Overall, 17 groin complications were identified (10.5%) in 5 patients (8.9%) who had had 8Fr sheaths inserted and 12 patients (11.4%) who had had 9Fr sheaths inserted. Major complications were identified in only 2 patients (1.2%), one patient in each of the 8Fr and 9Fr cohorts suffering a pseudoaneurysm requiring intervention. No retroperitoneal haematoma, infection, acute limb ischaemia or ipsilateral DVT was identified. No significant difference in groin complications was observed between the 8Fr and 9Fr femoral arteriotomy cohorts or between the MT patients that did or did not receive adjunctive IVT. CONCLUSION: In the setting of MT with IVT, off-label use of an 8Fr Angio-Seal VIP for closure of a femoral arteriotomy following use of a 9Fr sheath has a similar safety profile to the licensed use of an 8Fr Angio-Seal VIP for closure of a femoral arteriotomy following use of an 8Fr sheath or smaller.

Effects of the Vertebral Artery Ostium/Subclavian Artery Angle on In-Stent Restenosis after Vertebral Artery Ostium Stenting.

METHODS: Between January 2016 and October 2018, sixty-four consecutive patients who underwent a total of 66 stenting procedures were screened for symptomatic and asymptomatic atherosclerotic VAOS. Of these patients, 57 had complete follow-up data. The baseline patient demographics and morphological features of the VAO were recorded. Potential factors influencing ISR, including conventional cerebrovascular disease risk factors, were assessed, together with outcome events including recurrent transient ischemic attack (TIA), stroke, and vascular-related mortality. RESULTS: The average follow-up period was 13.2 ± 4.6 months. Technical success was achieved in all interventions. The degree of stenosis was reduced from 77.2 ± 6.1% to 13.7 ± 8.9% after the procedure. ISR was detected in eight treated vessels (14.0%) and occlusion in two (5.3%) arteries. Of the 57 patients, one had an ischemic stroke and 5 had TIAs. The angle of the VAO at the subclavian artery was associated with the risk of restenosis (preoperative, P = 0.04; postoperative, P = 0.02). CONCLUSIONS: Stenting is a feasible and effective treatment for VAOS. The angle of the VAO at the subclavian artery may contribute to the development of ISR.

Applications of Head-Mounted Displays and Smart Glasses in Vascular Surgery.

OBJECTIVES: Advances in virtual, augmented and mixed reality have led to the development of wearable technologies including head mounted displays (HMD) and smart glasses. While there is a growing interest on their potential applications in health, only a few studies have addressed so far their use in vascular surgery. The aim of this review was to summarize the fundamental notions associated with these technologies and to discuss potential applications and current limits for their use in vascular surgery. METHODS: A comprehensive literature review was performed to introduce the fundamental concepts and provide an overview of applications of HMD and smart glasses in surgery. RESULTS: HMD and smart glasses demonstrated a potential interest for the education of surgeons including anatomical teaching, surgical training, teaching and telementoring. Applications for pre-surgical planning have been developed in general and cardiac surgery and could be transposed for a use in vascular surgery. The use of wearable technologies in the operating room has also been investigated in both general and cardiovascular surgery and demonstrated its potential interest for image-guided surgery and data collection. CONCLUSION: Studies performed so far represent a proof of concept of the interest of HMD and smart glasses in vascular surgery for education of surgeons and for surgical practice. Although these technologies exhibited encouraging results for applications in vascular surgery, technical improvements and further clinical research in large series are required before hoping using them in daily clinical practice.

A Clampless Technique to Facilitate Successful End-to-End Anastomosis in Small Vessels With Spasm.

End-to-end anastomosis in small arteries can be challenging, especially when the stumps are in spasm after traumatic transection. We describe a novel technique to facilitate such anastomoses under local anesthesia, presenting a 24-year old patient who suffered complete traumatic transection of the left ulnar artery. After having found and prepared the proximal and distal stumps, a soft polyurethane feeding tube (La-med Healthcare, India) and a vein cannula were inserted in the proximal and distal stump, respectively, without using vascular clamps. The manipulation of the catheters offered excellent visualization and widening of the anastomotic line, enabling simultaneous infusion of heparinized saline or vasodilating agents. The anastomosis was completed with no stenosis and pulpable pulses were restored immediately postoperatively. At 1-month follow-up, the Allen test was normal with a normal regular flow of the ulnar artery at duplex ultrasound. The described technique ensures efficient sealing avoiding clamping, casts the small lumens, provides optimal visualization of the anastomotic aspects and prevents stenosis. We believe it should have a place in the surgeon's armamentarium.

Use of covered stent grafts as treatment of traumatic venous injury to the inferior vena cava and iliac veins: A systematic review.

OBJECTIVE: Venous injury to the inferior vena cava or iliac veins is rare but can result in high mortality rates. Traditional treatment by repair or ligation can be technically demanding. A relatively new treatment modality is the use of a covered stent to cover the venous defect. The aim of the present systematic review was to assess the techniques, results, and challenges of covered stent graft repair of traumatic injury to the inferior vena cava and iliac veins. METHODS: The PubMed (Medline) and Embase databases were systematically searched up to September 2020 by two of us (R.R.S. and D.D.) independently for studies reporting on covered stenting of the inferior vena cava or iliac veins after traumatic or iatrogenic injury. A methodologic quality assessment was performed using the modified Newcastle-Ottawa scale. Data were extracted for the following parameters: first author, year of publication, study design, number of patients, type and diameter of the stent graft, hemostatic success, complications, mortality, postoperative medication, follow-up type and duration, and venous segment patency. The main outcome was clinical success of the intervention, defined as direct hemostasis, with control of hemorrhage, hemodynamic recovery, and absence of contrast extravasation. RESULTS: From the initial search, which yielded 1884 records, a total of 28 studies were identified for analysis. All reports consisted of case reports, except for one retrospective cohort study and one case series. A total of 35 patients had been treated with various covered stent grafts, predominantly thoracic or abdominal aortic endografts. In all patients, the treatment was technically successful. The 30-day mortality rate for the entire series was 2.9%. Three perioperative complications were described: one immediate stent occlusion, one partial thrombosis, and one pulmonary embolism. Additional in-stent thrombus formation was seen during follow-up in three patients, leading to one stent graft occlusion (asymptomatic). The postoperative anticoagulation strategy was highly heterogeneous. The median follow-up was 3 months (range, 0.1-84 months). However, follow-up with imaging studies was not performed in all cases. CONCLUSIONS: In selected cases of injury to the inferior vena cava and iliac veins, covered stent grafts can be successful for urgent hemostasis with good short-term results. Data on long-term follow-up are very limited.

Pilot study of minimum occlusive force of vascular clamps on arterial vessels in rats.

Our aims were to determine the accuracy of an improved formula for determining the minimum occlusive force (MOF) of a vascular clamp on rats' abdominal aortas, compare our findings with the calculated theoretical MOF, and provide reference data for clinical research and development of medical instruments that cause minimal damage. We created a vessel closure model and developed a formula for calculating the theoretical MOF of arterial vessels when they are occluded. This formula utilises the blood pressure in the blood vessel, its diameter, and the width of the vascular clamp. We then measured the actual MOF in 24 rat abdominal aortic segments with different diameters and different blood pressures and compared the theoretical and actual MOFs. Analysis of the experimental data showed a probability of 0.315, which means that, under the condition of normal distribution, the difference between the theoretical and actual MOF is not significant at the α = 0.05 level. Thus, the actual measured MOF tended to be consistent with the theoretical MOF calculated by the formula we developed. The improved formula will provide a reference for clinical research and development of medical instruments that cause minimal injury, thus contributing to the development of microsurgery.

Early thrombosis after iliac stenting for venous outflow occlusion is related to disease severity and type of anticoagulation.

BACKGROUND: Stenting of the iliac venous system is often performed for symptomatic obstruction, with high patency rates reported. However, patients with post-thrombotic disease and those with more extensive obstruction have experienced poorer outcomes, including a higher rate of early post-stent thrombosis. In the present study, we examined the outcomes of patients with complete venous outflow occlusion. We focused on the variables associated with early post-stenting thrombosis to identify opportunities to reduce its incidence. METHODS: From 2010 to 2020, the patients who had undergone stenting for chronic obstruction of the common femoral vein, iliac veins, and/or inferior vena cava were retrospectively reviewed. The pre- and intraoperative imaging studies were examined to identify those who had had total occlusion of one venous outflow segment (type III disease) or multiple venous outflow segments (type IV disease). The patient characteristics and procedural and post-stent variables were recorded. The post-procedure follow-up visits and imaging studies were reviewed to determine stent patency and thrombotic complications. Key variables were studied to determine their association with early stent reocclusion. RESULTS: A total of 106 patients were identified, including 43 with type III (40.6%) and 63 with type IV (59.4%) disease. The mean patient age was 49.8 ± 13.7 years, and the mean stented length was 177.3 ± 63 mm. Stainless steel Wallstents were used solely in 44% of the cases, with a variety of nitinol stents used in the remainder. Femoral vein inflow was minimally diseased in 50% of the cases, moderately diseased in 26%, and severely diseased or occluded in 24%. Antiplatelet medications were prescribed after intervention for 52.8% and anticoagulation medication for 95.3% of the patients. Occlusion of the stented segment occurred within 3 months in 25.5%. Primary patency was 74.5% at 3 months, 63.9% at 12 months, and 58.5% at 3 years. Secondary patency was 93.4% at 3 months and 76.1% at 3 and 5 years. Univariate analysis of variables related to early stent thrombosis identified the presence of a hypercoagulable state, type IV obstruction, and the type of anticoagulation used after stenting were associated with early stent thrombosis. On multivariate analysis, each of these variables was independently associated with early stent thrombosis. The presence of type IV obstruction (odds ratio [OR], 4.596; 95% confidence interval [CI], 1.424-18.109) or a hypercoagulable state (OR, 3.835; 95% CI, 1.207-12.871) was associated with significantly greater odds of reocclusion than was class III obstruction and no hypercoagulable state. Treatment with low-molecular-weight heparin for >10 days was associated with significantly lower odds (OR, 0.012; 95% CI, 0.001-0.130) of reocclusion. CONCLUSIONS: Patients who require recanalization of a completely occluded venous outflow tract before stenting have a high rate of early reocclusion. Patients with more extensive occlusion and a hypercoagulable state have greater odds of reocclusion. Treatment with low-molecular-weight heparin for >10 days reduced the odds of early reocclusion.

Microvascular anastomotic arterial coupling: A systematic review.

INTRODUCTION: There are several reasons microsurgeons may not use a coupler device in arterial anastomosis: may be thick-walled, non-pliable due to atherosclerotic calcification or present vessel geometrical discrepancies. This review summarises the current applications, efficacy and troubleshooting of microvascular coupler devices in arterial end-to-end anastomosis. METHODS: A systematic review of the literature was performed in November 2020 across 4 electronic databases and in accordance with the PRISMA guidelines. All studies comprised the data synthesis that reported the use of a microvascular coupler device for arterial end-to-end anastomosis. Data were extracted and collected in three groups of standardised variables: study, anastomosis-related and technical characteristics. RESULTS: Out of the 7,690 articles identified, 20 were included in the final data synthesis. Included studies involved a total of 1639 patients, who underwent 670 arterial and 1,124 venous anastomoses. Out of all arterial anastomoses, 351 were performed in free tissue transfers in head and neck, 117 in breast, 4 in upper extremity and 5 in lower extremity reconstruction, whereas the remaining were not specified. The total arterial coupler anastomosis success rate reported was 92.1% (617/670). Fifty-three (8%) arterial anastomoses were reported to result in either troubleshooting events or intra- or post-operative failures, most being reported in extremity reconstructions. CONCLUSIONS: Arterial coupling is not widespread with predominant use in head and neck and chest reconstructions, and total reported efficacy of 92.1%. Microsurgeons are reluctant to routinely use current widespread coupler devices as a result of inherent arterial characteristics. This study delivered collective recommendations, 'do's and don'ts' of microvascular arterial coupling.

A systematic review of the quality of cardiovascular surgery studies that extracted data from the MAUDE database.

OBJECTIVE: To investigate opportunities and limitations of using the Manufacturer and User Facility Device Experience (MAUDE) database for cardiovascular surgery research, we analyzed the quality of studies having ever used MAUDE, in the field of cardiovascular surgery. METHODS: We systematically searched the Cochrane Library, PubMed, EMBASE, and Google Scholar for randomized and nonrandomized studies, from inception to July 2019. Two authors evaluated the quality of the retrieved observational studies, according to the National Institutes of Health quality assessment tool for either case series or cross-sectional studies. These tools quantify the quality of case series and cohorts/cross-sectional studies, respectively, with nine and 14 queries. RESULTS: Fifty-eight studies were included in the final qualitative review. Of 58 identified studies, 32 were case series, 8 were abstracts of case series, and 13 were reviews or case discussion with an included series from MAUDE. Also, five articles were cross-sectional studies. Of the 32 formal case series, 26 (81%) were found to have poor quality. The most common reasons for a poor quality designation included a lack of consecutive participants, undetermined comparability of participants, and undetermined follow-up adequacy. Only one out of five cross-sectional studies had fair quality; four others were evaluated as poor quality studies. CONCLUSIONS: Cardiovascular surgery studies using the MAUDE database, whether case series or cross-sectional design, are mostly of poor quality. Their low quality is partly caused by poor study design, but mainly by intrinsic limitations to the MAUDE database: cases recruited are not consecutive; patient characteristics are not detailed enough to allow a meaningful comparison of patient characteristics between different patient entries; outcome measures are unclear; there is a limited follow-up; and time-to-event data are lacking. We conclude that the quality of cardiovascular surgery publications that rely on data from MAUDE could be improved if investigators were to extract all relevant data points from MAUDE entries, then apply standard quality assessment tools in compiling and reporting the data. MAUDE might be improved if it used medical case report standards during the process of reporting and indexing adverse events. To calculate the incidence rate of any adverse event, all event-free cases, as well as all adverse events in patients using a device, are required. Neither of these two variables is available in the MAUDE at the time of writing.