External stenting and disease progression in vein grafts 1 year after open surgical repair of popliteal artery aneurysm

OBJECTIVE

Open surgical repair remains the gold standard treatment for popliteal artery aneurysms (PAA). The objective of this study was to evaluate the safety of external stenting and its medium-term effect on vein graft disease after open PAA repair.

METHODS

Between December 2017 and September 2019, 12 consecutive patients with PAA underwent open surgical repair with externally stented saphenous vein grafts. Duplex ultrasound scanning of the grafts was performed at discharge and at 3, 6, and 12 months after the procedure to evaluate graft patency, average lumen diameter and lumen uniformity.

RESULTS

Eleven patients underwent aneurysm ligation and bypass grafting and one patient was treated with aneurysm exclusion and interposition of a venous segment. External stenting of the vein graft was successful in all patients. The mean follow-up time was 12 months (range, 7-17 months), with a primary patency rate of 100% and no graft revisions or reinterventions. The mean lumen diameters at 3, 6, and 12 months were 5.9 ± 1.2 mm, 5.7 ± 0.8 mm, and 5.7 ± 0.7 mm, respectively, with no significant changes between 3 and 6 (P = .34) and between 6 and 12 months (P = .34). The coefficient of variance at 3, 6, and 12 months was 8.2 ± 9.3, 9.4 ± 7.2, and 10.4 ± 8.9, respectively, with no significant change between 3 and 6 months (P = .78) or 6 and 12 months (P = .98). No mortality or amputations were recorded throughout the follow-up period.

CONCLUSIONS

External stenting of vein grafts in open surgical repair of PAA is feasible and safe. This technique may potentially improve the outcomes of surgical repair in patients with PAA.

Fixed low-dose ultrasound-assisted catheter-directed thrombolysis followed by routine stenting of residual stenosis for acute ilio-femoral deep-vein thrombosis

Patients with ilio-femoral deep-vein thrombosis (DVT) are at high risk of developing the postthrombotic syndrome (PTS). In comparison to anticoagulation therapy alone, extended venography-guided catheter-directed thrombolysis without routine stenting of venous stenosis in patients with ilio-femoral DVT is associated with an increased risk of bleeding and a moderate reduction of PTS. We performed a prospective single-centre study to investigate safety, patency and incidence of PTS in patients with acute iliofemoral DVT treated with fixed-dose ultrasound-assisted catheter-directed thrombolysis (USAT; 20 mg rt-PA during 15 hours) followed by routing stenting of venous stenosis, defined as residual luminal narrowing >50%, absent antegrade flow, or presence of collateral flow at the site of suspected stenosis. A total of 87 patients (age 46 ± 21 years, 60% women) were included. At 15 hours, thrombolysis success ≥50% was achieved in 67 (77%) patients. Venous stenting (mean 1.9 ± 1.3 stents) was performed in 70 (80%) patients, with the common iliac vein as the most frequent stenting site (83%). One major (1%; 95% CI, 0–6%) and 6 minor bleedings (7%; 95%CI, 3–14%) occurred. Primary and secondary patency rates at 1 year were 87% (95% CI, 74–94%) and 96% (95% CI, 88–99%), respectively. At three months, 88% (95% CI, 78–94%) of patients were free from PTS according to the Villalta scale, with a similar rate at one year (94%, 95% CI, 81–99%). In conclusion, a fixed-dose USAT regimen followed by routine stenting of underlying venous stenosis in patients with iliofemoral DVT was associated with a low bleeding rate, high patency rates, and a low incidence of PTS.

Assessing the risk of recurrent venous thromboembolism--a practical approach

Recurrent venous thromboembolism (VTE) is associated with increased morbidity and mortality. This risk is lowered by anticoagulation, with a large effect in the initial phase following the venous thromboembolic event, and with a smaller effect in terms of secondary prevention of recurrence when extended anticoagulation is performed. On the other hand, extended anticoagulation is associated with an increased risk of major bleeding and thus leads to morbidity and mortality. Therefore, it is necessary to assess the risk of recurrence for VTE on an individual basis, and a recommendation for secondary prophylaxis should be specifically based on risk calculation of recurrence of VTE and bleeding. In this review, we provide a comprehensive summary of relevant risk factors for recurrent VTE and a practical approach for assessing the risk of recurrence in daily practice.

Surgical treatment of varicose veins and venous malformations in Klippel–Trenaunay syndrome

Background

Klippel–Trenaunay syndrome (KTS) is a mixed mesenchymal malformation characterised by varicose veins, venous and capillary malformations, and hypertrophy of soft tissue and bone. The purpose of this study was to evaluate the surgical outcomes in KTS patients to provide standards for comparison with endovenous therapy.

Methods

The clinical data of consecutive patient with KTS who underwent open venous surgical treatment between January 1987 and December 2008 were reviewed. Demographics, clinical presentation, operative data, and clinical outcomes were recorded. Follow-up information was obtained from the medical records, mailed questionnaires and phone calls. Descriptive statistics, the Kaplan–Meier method and Log-rank statistics were used where appropriate.

Results

Twenty-seven females and 22 males, (mean age 26.5 years, range 7.7–55.8) were included in this study. All had varicose veins, 36 (73%) had limb hypertrophy, and 33 (67%) had capillary malformations, with two of three clinical features present in all. The most frequent symptom was pain (N = 43, 88%). Forty-nine patients underwent operations on 53 limbs. Stripping of the GSV, small and accessory saphenous and lateral embryonic veins was performed in 17 (32%), 10 (19%), 9 (17%), and 15 (28%) limbs, respectively. Two patients developed deep vein thrombosis, one had pulmonary embolism (PE), and one patient had peroneal nerve palsy. Freedom from disabling pain at 1, 3 and 5 years was 95%, 77% and 59%, respectively, and freedom from secondary procedures was 78% at 3 years, and 74% at 5 years. At the last follow-up visit, the venous clinical severity score had decreased from 9.48 ± 3.27 to 6.07 ± 3.20 (P < 0.001).

Conclusions

In selected symptomatic patients with KT syndrome, open surgical treatment is safe and durable. Three-fourths of the patients remain free of disabling pain at five years, but secondary procedures are required in one-fourth of the patients. These data can serve as standards for comparison of endovenous therapy for KT syndrome.

Hypersensitivity to nickel in a patient treated with coil embolization for pelvic congestion syndrome

A 34-year-old woman had persistent symptoms of pelvic venous congestion syndrome and developed new symptoms of a systemic allergic reaction after coil embolization of both ovarian and internal iliac veins. Patch testing revealed hypersensitivity to nickel and palladium, both components of the coils used. After surgical removal of the coils and hysterectomy with salpingo-oophorectomy, all her symptoms resolved.

Fixed low-dose ultrasound-assisted catheter-directed thrombolysis for intermediate and high-risk pulmonary embolism

AIMS

No standardized local thrombolysis regimen exists for the treatment of pulmonary embolism (PE). We retrospectively investigated efficacy and safety of fixed low-dose ultrasound-assisted catheter-directed thrombolysis (USAT) for intermediate- and high-risk PE.

METHODS AND RESULTS

Fifty-two patients (65 ± 14 years) of whom 14 had high-risk PE (troponin positive in all) and 38 intermediate-risk PE (troponin positive in 91%) were treated with intravenous unfractionated heparin and USAT using 10 mg of recombinant tissue plasminogen activator per device over the course of 15 h. Bilateral USAT was performed in 83% of patients. During 3-month follow-up, two [3.8%; 95% confidence interval (CI) 0.5-13%] patients died (one from cardiogenic shock and one from recurrent PE). Major non-fatal bleeding occurred in two (3.8%; 95% CI, 0.5-13%) patients: one intrathoracic bleeding after cardiopulmonary resuscitation requiring transfusion, one intrapulmonary bleeding requiring lobectomy. Mean pulmonary artery pressure decreased from 37 ± 9 mmHg at baseline to 25 ± 8 mmHg at 15 h (P < 0.001) and cardiac index increased from 2.0 ± 0.7 to 2.7 ± 0.9 L/min/m(2) (P < 0.001). Echocardiographic right-to-left ventricular end-diastolic dimension ratio decreased from 1.42 ± 0.21 at baseline to 1.06 ± 0.23 at 24 h (n = 21; P < 0.001). The greatest haemodynamic benefit from USAT was found in patients with high-risk PE and in those with symptom duration < 14 days.

CONCLUSION

A standardized catheter intervention approach using fixed low-dose USAT for the treatment of intermediate- and high-risk PE was associated with rapid improvement in haemodynamic parameters and low rates of bleeding complications and mortality.

Diurnal changes of lower leg volume in obese and non-obese subjects

BACKGROUND/AIM

Obesity is a risk factor for chronic venous disease. However, the mechanisms behind this association are poorly understood. We tested the hypothesis that obese subjects have a higher diurnal leg volume increase compared with non-obese subjects.

METHODS

In this prospective cohort study including obese (body mass index, BMI ≥30 kg m(-)(2)) and non-obese (BMI ≤25 kg m(-)(2)) subjects without venous insufficiency, lower leg volume was assessed by optoelectronic volumetry in the morning and in the evening. All subjects underwent duplex ultrasound and light reflection rheography (venous pump power and venous refill time, VRT) to investigate lower extremity venous function. A pedometer was carried between the morning and evening visit to assess the daily number of footsteps. A backward multivariable linear regression model was used to determine factors associated with diurnal lower leg volume increase.

RESULTS

Forty-two limbs in 24 obese subjects and 29 limbs in 15 non-obese subjects were analyzed. Obese subjects had larger common femoral vein diameters (17.1±2.4 vs 15.5±2.4 mm, P<0.01) and slower peak, mean and minimal velocities (25.1±10.6 vs 44.3±14.3 cm s(-1); 6.8±2.4 vs 12.7±5.6 cm s(-1); -0.2±6.4 vs -6.3±11.9 cm s(-1); P<0.01 for all) than non-obese subjects. VRT was shorter in obese subjects (40.5±15.0 vs 51.0±12.1 s, P<0.01) and decreased significantly in the course of the day only in obese subjects (P<0.01). Obesity, male gender, CEAP (Clinical-Etiology-Anatomy-Pathophysiology) class, total time between the two visits and difference between morning and evening VRT were positively associated with higher lower leg volume increase; morning VRT and the total number of footsteps showed a negative association (P<0.04 for all).

CONCLUSION

Obesity was found to be an independent predictor of higher diurnal leg volume increase. One potential mechanism is a progressive failure of venous valve function in the course of the day in obese subjects.

Catheter-based treatment of ilio-femoral deep vein thrombosis - an update on current evidence

Ilio-femoral deep vein thrombosis (DVT) has a high rate of long-term morbidity in the form of the postthrombotic syndrome (PTS). Therefore, management of acute thrombosis should not only focus on the prevention of acute complications such as propagation or embolisation of the initial clot but also on preventing PTS and recurrent thrombosis. Contemporary catheter-based treatments of deep vein thrombosis have proven to be safe and effective in selected patients. Current guidelines recommend medical therapy with anticoagulation alone for all but the most severe, limb-threatening thrombosis. They additionally allow for consideration of catheter-based treatment in patients with acute DVT and low risk of bleeding complications to prevent PTS. Recent studies favoring interventional therapy have not been included in these guidelines. Data on long-term outcome is expected to be published soon, clarifying and very likely strengthening the role of catheter-based treatments in the management of acute ilio-femoral DVT.

Bipolar gene flow in deep-sea benthic foraminifera

Despite its often featureless appearance, the deep-ocean floor includes some of the most diverse habitats on Earth. However, the accurate assessment of global deep-sea diversity is impeded by a paucity of data on the geographical ranges of bottom-dwelling species, particularly at the genetic level. Here, we present molecular evidence for exceptionally wide distribution of benthic foraminifera, which constitute the major part of deep-sea meiofauna. Our analyses of nuclear ribosomal RNA genes revealed high genetic similarity between Arctic and Antarctic populations of three common deep-sea foraminiferal species (Epistominella exigua, Cibicides wuellerstorfi and Oridorsalis umbonatus), separated by distances of up to 17, 000 km. Our results contrast with the substantial level of cryptic diversity usually revealed by molecular studies, of shallow-water benthic and planktonic marine organisms. The very broad ranges of the deep-sea foraminifera that we examined support the hypothesis of global distribution of small eukaryotes and suggest that deep-sea biodiversity may be more modest at global scales than present estimates suggest.

Aberrant intermolecular disulfide bonding in a mutant HLA-DM molecule: implications for assembly, maturation, and function

HLA-DM (abbreviated DM) is an MHC-encoded glycoprotein that catalyzes the selective release of peptides, including class II-associated invariant chain peptides, from MHC class II molecules. To perform its function, DM must assemble in the endoplasmic reticulum (ER), travel to endosomes, and interact productively with class II molecules. We have described previously an EBV-transformed B cell line, 7.12.6, which displays a partial Ag presentation defect and expresses a mutated DM beta-chain with Cys79 replaced by Tyr. In this study, we show that HLA-DR molecules in 7.12.6 have a defect in peptide loading and accumulate class II-associated invariant chain peptides (CLIP). Peptide loading is restored by transfection of wild-type DMB. The mutant DM molecules exit the ER slowly and are degraded rapidly, resulting in greatly reduced levels of mutant DM in post-Golgi compartments. Whereas wild-type DM forms noncovalent alphabeta dimers, such dimers form inefficiently in 7.12.6; many mutant DM beta-chains instead form a disulfide-bonded dimer with DM alpha. Homodimers of DM beta are also detected in 7.12.6 and in the alpha-chain defective mutant, 2.2.93. We conclude that during folding of wild-type DM, the native conformation is stabilized by a conserved disulfide bond involving Cys79beta and by noncovalent contacts with DM alpha. Without these interactions, DM beta can form malfolded structures containing interchain disulfide bonds; malfolding is correlated with ER retention and accelerated degradation.