Multicenter observational study of the gore excluder conformable endograft for endovascular abdominal aortic repair: Initial results

Objective

Endovascular repair (EVAR) has become the standard of care for treatment of abdominal aortic aneurysms. However, a significant number of EVAR remains outside the IFU, especially in cases of severe proximal angulation (>60 degrees), resulting in failure. The new device GORE EXCLUDER Conformable AAA Endoprosthesis (W. L. Gore & Associates, Flagstaff, Ariz) has been designed to accommodate neck angulation, due to conformability and angulation control. The aim of this multicenter study is to report the initial results of this device.

Methods

From March 2019 to January 2021, the data of all consecutive patients with AAA treated with the Gore Excluder Conformable endograft at 4 vascular centers were reviewed. Patients were followed using a standardized protocol, with CT-scan at 1, 6 and 12 months, and then yearly. The primary endpoint was technical success and secondary outcomes were postoperative morbidity, rate of endoleak (EL) and any aneurysm-related re-interventions during follow-up.

Results

Among the 32 patients included, most were men with a mean age of 77 years old (range 60-92). Half of patients were smokers and 72% had hypertension. The mean diameter of AAA was 62 mm (47-90). The mean length of aortic neck was 26 mm (10-69), the mean diameter 23 mm (16-31) and the median neck angulation was 81 degrees (range 40-110). The mean procedural duration was 102 min (54-153) with a mean time of scopy of 24 min (8-47) and a total volume of contrast of 101 ml (40-165). Thirteen iliac branch device have been used in 7 patients. The technical success was 97% with 1 type Ia EL (3%). In the post-operative period, 4 medical and 3 surgical complications were observed. Two reinterventions were needed with an iliac stenting for a stenosis and a correction of a femoral false aneurysm. During the mean follow-up of 7 months, 2 type Ia ELs were observed. One spontaneously resolved and the other one was followed. One distal limb extension was succesfully implanted at 3 months for a type Ib EL for a total rate of reintervention of 9%. No migration was observed. No death occured.

Conclusion

The use of the Gore Excluder Conformable endograft seems to be safe and effective in difficult anatomies and especially high angulation. It allows for precise deployment without the need for additional contrast or operation time. Longer follow-up and more patients are required to confirm these excellent initials results.

Tele-proctoring in vascular surgery implementing percutaneous creation of arteriovenous fistula

Objective

Percutaneous ultrasound-guided creation of an arteriovenous fistula (pAVF) for hemodialysis access is a relatively novel procedure with promising technical success and patency rates. The vascular surgery departments of two collaborating Swiss hospitals had decided to introduce the technique to their services. A surgeon experienced in the technique (AM) was supposed to come to Switzerland and proctor the first four procedures. Due to the SARS-CoV-2 pandemic and travel restrictions, this was not possible and we decided to perform the first four pAVF procedures tele-proctored via a video conference system. We present the setup and our experience with tele-proctoring.

Methods

The setup relied on an all-in-one live video production device, video encoder, video streamer and video recorder (Pearl-2, Epiphan), which made it possible to simultaneously transmit the live image from the ultrasound device (GE Logiq S8, linear probe 9L-D) and a live image from a video camera (JVC Camcorder G/-HM440E, Japan), both connected via HDMI (Figure). The live stream was shared with the proctor in France and the device support team in the US, using an encrypted Swiss video client (www.vitimway.ch). The setup was tested with all parties three days in advance.

Results

All 4 procedures started with a verbal briefing and a live ultrasound scan. All steps of the procedures were taken under the proctor’s instruction and supervision. The proctor gave on average 21 instructions per procedure. An average 4 were device-related but these became less frequent as we proceeded. The operators consulted the proctor on average 5 times per procedure. The average duration of the procedure was 34 min. The pAVF creation was successful in all 4 patients, with an average fistula flow measured at the end of the procedure of 600 ml/min.

Conclusion

Our experience showed us that pAVF creation, which is a procedure performed entirely under sonographic guidance lends itself particularly well to tele-proctoring. The simultaneous transmission of the live sonographic image and the live image of the operators' hands allowed the proctor to supervise and correct the key steps of the procedures. The simplicity of the set-up and the quality of proctor-operator interaction was such a positive experience that we can well envisage a much wider use of tele-proctoring in the future.

Early-cannulation arteriovenous grafts are safe and effective in avoiding recurrent tunneled central catheter infection

Objective

Tunneled central venous catheter infection (TCVCi) is a common complication that often necessitates removal of the TCVC and a further TCVC. Theoeretically, insertion of an early-cannualtion graft (ecAVG) early after TCVC infection is possible but not widely practiced with concerns over safety and infection in the ecAVG. With 8 years of ecAVG experience, the aim of this study was to compare the outcomes following TCVC infection, comparing replacement with TCVC (TCVCr) versus immediate ecAVG (ecAVGr).

Methods

Retrospective comparison of two cohorts, who underwent replacement of an infected TCVC either by an early cannulation graft (n = 18) or by a further central catheter (n = 39).

Data were abstracted from a prospectively completed electronic patient record and collected on patient demographics, TCVC insertion, duration and infection, including culture proven bacteriaemia and subsequent access interventions.

Results

18/299 patients identified from 2012-2020 had an ecAVG implanted as treatment for a TCVCi. In a one-year time-period (1/1/2015 -31/12/2015) out of 222 TCVC inserted, 39 were as a replacement following a TCVCi. No patient with an ecAVGr developed an immediate infection, nor complication from the procedure. The rate of subsequent vascular access infection was significantly more frequent for those with TCVCr than with an ecAVGr (0.6 vs. 0.1/patient/ 1000 HD days, p < 0.000). The number of further TCVC required was significantly higher in the TCVCr group (7.1 vs. 0.4/patient/ 1000 HD days, p = 0.000).

Conclusion

An ecAVG early following a TCVC infection is safe, reduces the incidence of subsequent infectious complications and reduces the number of TCVC required, with a better functional patency.

First experience with percutaneous arteriovenous fistula creation using the Ellipsys® vascular access system

Objective

Percutaneous creation of arteriovenous fistulae (pAVF) has been developed as an alternative to the creation of an upper arm cephalic or basilic vein fistula. Several studies have shown high technical success rates and comparable time of maturation. To our knowledge, the technique has not been used in Switzerland before.

Methods

Prospective data collection of the first consecutive patients undergoing the creation of pAVF between April and July 2020 at two vascular surgery centres.

Results

Seven patients underwent pAVF creation with the Ellipsys® vascular access system under regional anaesthesia for maximum vasodilation. The procedures were performed entirely under sonographic control without the use of fluoroscopy. The cephalic or basilic vein was punctured and the puncture needle advanced under sonographic control through the cubital perforator vein into the proximal radial artery. The Ellipsys® catheter was advanced over a guidewire and activated to create the fistula between the proximal radial artery and the perforator vein. The fistula was further dilated with a 5mm PTA balloon. We achieved technical success in 6 patients. In one patient with small and spastic vessels, the needle could not be advanced into the radial artery. A conventional upper arm cephalic fistula was created during the same procedure. In three patients primary maturation was achieved and the cephalic vein or distal basilic vein could be punctured for dialysis without any adjunct procedures. One patient required three additional procedures before the fistula could be used successfully (additional angioplasty of the fistula, superficialisation of the basilic vein and correction of a cubital vein stenosis by excision and end-to-end anastomosis). One patient required superficialisation of the basilic vein and one patient transposition of the arterialised brachial vein. Maturation was achieved in six pAVF after a mean of 158 days with a mean fistula flow of 920 ml/ min.

Conclusion

We achieved high technical success and maturation rates in our first patients undergoing pAVF creation with the Ellipsys® system. Prerequisites are suitable anatomy of the cubital perforator vein and good skills in sonography and endovascular techniques. We believe that pAVF is a promising alternative to the creation of a conventional upper arm fistula in patients unsuitable for a distal radio-cephalic fistula.

Early-Cannulation Arteriovenous Grafts Are Safe and Effective in Avoiding Recurrent Tunneled Central Catheter Infection

OBJECTIVES

Tunneled central venous catheter infection (TCVCi) is a common complication that often necessitates removal of the TCVC and replacement by a further TCVC. Theoretically, insertion of an early - cannulation graft (ecAVG) early after TCVC infection is possible but not widely practiced with concerns over safety and infection in the ecAVG. With 8 years of ecAVG experience, the aim of this study was to compare the outcomes following TCVC infection, comparing replacement with TCVC (TCVCr) versus immediate ecAVG (ecAVGr).

DESIGN

Retrospective comparison of 2 cohorts, who underwent replacement of an infected TCVC either by an early cannulation graft (n = 18) or by a further central catheter (n = 39).

METHODS

Data were abstracted from a prospectively completed electronic patient record and collected on patient demographics, TCVC insertion, duration and infection, including culture proven bacteriaemia and subsequent access interventions.

RESULTS

Eighteen of 299 patients identified from 2012 to 2020 had an ecAVG implanted as treatment for a TCVCi. In a 1-year time-period (January 1, 2015-December 31, 2015) out of 222 TCVC inserted, 39 were as a replacement following a TCVCi. No patient with an ecAVGr developed an immediate infection, nor complication from the procedure. The rate of subsequent vascular access infection was significantly more frequent for those with a TCVCr than with an ecAVGr (0.6 vs. 0.1/patient/1000 HD days, P< 0.000). The number of further TCVC required was significantly higher in the TCVCr group (7.1 vs. 0.4/patient/1000 HD days, P= 0.000).

CONCLUSIONS

An ecAVG early following a TCVC infection is safe, reduces the incidence of subsequent infectious complications and reduces the number of TCVC required, with a better functional patency.

Evaluation of malignant effusions using MR-based T1 mapping

Our aim was to investigate the diagnostic yield of rapid T1-mapping for the differentiation of malignant and non-malignant effusions in an ex-vivo set up. T1-mapping was performed with a fast modified Look-Locker inversion-recovery (MOLLI) acquisition and a combined turbo spin-echo and inversion-recovery sequence (TMIX) as reference. A total of 13 titrated albumin-solutions as well as 48 samples (29 ascites/pleural effusions from patients with malignancy; 19 from patients without malignancy) were examined. Samples were classified as malignant-positive histology, malignant-negative histology and non-malignant negative histology. In phantom analysis both mapping techniques correlated with albumin-content (MOLLI: r = − 0.97, TMIX: r = − 0.98). MOLLI T1 relaxation times were shorter in malignancy-positive histology fluids (2237 ± 137 ms) than in malignancy-negative histology fluids (2423 ± 357 ms) as well as than in non-malignant-negative histology fluids (2651 ± 139 ms); post hoc test for all intergroup comparisons: < 0.05. ROC analysis for differentiation between malignant and non-malignant effusions (malignant positive histology vs. all other) showed an (AUC) of 0.89 (95% CI 0.77–0.96). T1 mapping allows for non-invasive differentiation of malignant and non-malignant effusions in an ex-vivo set up.

Quantitative MRI of the liver: Evaluation of extracellular volume fraction and other quantitative parameters in comparison to MR elastography for the assessment of hepatopathy

BACKGROUND

Chronic liver diseases pose a major health problem worldwide, while common tests for diagnosis and monitoring of diffuse hepatopathy have considerable limitations. Preliminary data on the quantification of hepatic extracellular volume fraction (ECV) with magnetic resonance imaging (MRI) for non-invasive assessment of liver fibrosis are encouraging, with ECV having the potential to overcome several of these constraints.

PURPOSE

To clinically evaluate ECV provided by quantitative MRI for assessing the severity of liver disease.

MATERIALS AND METHODS

In this prospective study, multiparametric liver MRI, including T1 mapping and magnetic resonance elastography (MRE), was performed in subjects with and without hepatopathy between November 2018 and October 2019. T1, T2, T2*, proton density fat fraction and stiffness were extracted from parametric maps by regions of interest and ECV was calculated from T1 relaxometries. Serum markers of liver disease were obtained by clinical database research. For correlation analysis, Spearman rank correlation was used. ROC analysis of serum markers and quantitative MRI data for discrimination of liver cirrhosis was performed with MRE as reference standard.

RESULTS

109 participants were enrolled (50.7 ± 16.1 years, 61 men). ECV, T1 and MRE correlated significantly with almost all serum markers of liver disease, with ECV showing the strongest associations (up to r = 0.67 with MELD, p < 0.01). ECV and T1 correlated with MRE (0.75 and 0.73, p < 0.01 each). ECV (AUC 0.89, cutoff 32.2%, sensitivity 85%, specificity 87%) and T1 mapping (AUC 0.85, cutoff 592.5 ms, sensitivity 83%, specificity 75%) featured good performances in detection of liver cirrhosis with only ECV performing significantly superior to model of end stage liver disease (MELD), AST/ALT ratio and international normalized ratio (p < 0.01, respectively).

CONCLUSION

Quantification of hepatic extracellular volume fraction with MRI is suitable for estimating the severity of liver disease when using MRE as the standard of reference. It represents a promising tool for non-invasive assessment of liver fibrosis and cirrhosis.

Parameters predicting COVID-19-induced myocardial injury and mortality

Clinical manifestations of COVID-19 affect many organs, including the heart. Cardiovascular disease is a dominant comorbidity and prognostic factors predicting risk for critical courses are highly needed. Moreover, immunomechanisms underlying COVID-induced myocardial damage are poorly understood.

OBJECTIVE

To elucidate prognostic markers to identify patients at risk.

RESULTS

Only patients with pericardial effusion (PE) developed a severe disease course, and those who died could be identified by a high CD8/Treg/monocyte ratio. Ten out of 19 COVID-19 patients presented with PE, 7 (78%) of these had elevated APACHE-II mortality risk-score, requiring mechanical ventilation. At admission, PE patients showed signs of systemic and cardiac inflammation in NMR and impaired cardiac function as detected by transthoracic echocardiography (TTE), whereas parameters of myocardial injury e.g. high sensitive troponin-t (hs-TnT) were not yet increased. During the course of disease, hs-TnT rose in 8 of the PE-patients above 16 ng/l, 7 had to undergo ventilatory therapy and 4 of them died. FACS at admission showed in PE patients elevated frequencies of CD3⁺CD8⁺ T cells among all CD3+ T-cells, and lower frequencies of Tregs and CD14⁺HLA^-DR⁺-monocytes. A high CD8/Treg/monocyte ratio predicted a severe disease course in PE patients, and was associated with high serum levels of antiviral cytokines. By contrast, patients without PE and PE patients with a low CD8/Treg/monocyte ratio neither had to be intubated, nor died.

CONCLUSIONS

PE predicts cardiac injury in COVID-19 patients. Therefore, TTE should be performed at admission. Immunological parameters for dysfunctional antiviral immunity, such as the CD8/Treg/monocyte ratio used here, supports risk assessment by predicting poor prognosis.

Parameters predicting COVID-19-induced myocardial injury and mortality

Clinical manifestations of COVID-19 affect many organs, including the heart. Cardiovascular disease is a dominant comorbidity and prognostic factors predicting risk for critical courses are highly needed. Moreover, immunomechanisms underlying COVID-induced myocardial damage are poorly understood.

OBJECTIVE

To elucidate prognostic markers to identify patients at risk.

RESULTS

Only patients with pericardial effusion (PE) developed a severe disease course, and those who died could be identified by a high CD8/Treg/monocyte ratio. Ten out of 19 COVID-19 patients presented with PE, 7 (78%) of these had elevated APACHE-II mortality risk-score, requiring mechanical ventilation. At admission, PE patients showed signs of systemic and cardiac inflammation in NMR and impaired cardiac function as detected by transthoracic echocardiography (TTE), whereas parameters of myocardial injury e.g. high sensitive troponin-t (hs-TnT) were not yet increased. During the course of disease, hs-TnT rose in 8 of the PE-patients above 16 ng/l, 7 had to undergo ventilatory therapy and 4 of them died. FACS at admission showed in PE patients elevated frequencies of CD3⁺CD8⁺ T cells among all CD3+ T-cells, and lower frequencies of Tregs and CD14⁺HLA^-DR⁺-monocytes. A high CD8/Treg/monocyte ratio predicted a severe disease course in PE patients, and was associated with high serum levels of antiviral cytokines. By contrast, patients without PE and PE patients with a low CD8/Treg/monocyte ratio neither had to be intubated, nor died.

CONCLUSIONS

PE predicts cardiac injury in COVID-19 patients. Therefore, TTE should be performed at admission. Immunological parameters for dysfunctional antiviral immunity, such as the CD8/Treg/monocyte ratio used here, supports risk assessment by predicting poor prognosis.

Probiotic helminth administration in relapsing-remitting multiple sclerosis: a phase 1 study

BACKGROUND

Probiotic treatment strategy based on the hygiene hypothesis, such as administration of ova from the non-pathogenic helminth, Trichuris suis, (TSO) has proven safe and effective in autoimmune inflammatory bowel disease.

OBJECTIVE

To study the safety and effects of TSO in a second autoimmune disease, multiple sclerosis (MS), we conducted the phase 1 Helminth-induced Immunomodulatory Therapy (HINT 1) study.

METHODS

Five subjects with newly diagnosed, treatment-naive relapsing-remitting multiple sclerosis (RRMS) were given 2500 TSO orally every 2 weeks for 3 months in a baseline versus treatment control exploratory trial.

RESULTS

The mean number of new gadolinium-enhancing magnetic resonance imaging (MRI) lesions (n-Gd+) fell from 6.6 at baseline to 2.0 at the end of TSO administration, and 2 months after TSO was discontinued, the mean number of n-Gd+ rose to 5.8. No significant adverse effects were observed. In preliminary immunological investigations, increases in the serum level of the cytokines IL-4 and IL-10 were noted in four of the five subjects.

CONCLUSION

TSO was well tolerated in the first human study of this novel probiotic in RRMS, and favorable trends were observed in exploratory MRI and immunological assessments. Further investigations will be required to fully explore the safety, effects, and mechanism of action of this immunomodulatory treatment.