April 2023 Issue 07 www.renalinterventions.net
In this issue:
ASDIN:
Programme highlights page 4
Saravanan Balamuthusamy on machine learning in dialysis access page 8
Non-invasive histotripsy performed in patient with primary solid renal tumour Tze Min Wah, clinical lead for the interventional oncology programme at Leeds Teaching Hospitals NHS Trust (Leeds, UK), has performed the first treatment with histotripsy in the CAIN trial of the technology. THE TRIAL IS A PHASE I PROSPECTIVE, multicentre study designed to evaluate the safety and technical success of histotripsy in targeting and destroying primary solid renal tumours completely non-invasively and without the need for incisions or needles. The trial is named in honour of Charles Cain, former chair of biomedical engineering at the University of Michigan (Detroit, USA). Cain was a primary inventor and leader in the technology’s development, who passed away in March 2020. Current kidney therapies such as partial nephrectomy, which is invasive, and the less invasive thermal ablation exhibit complications from bleeding and infection. While surgical intervention is the “gold standard” in removing kidney tumours, a non-invasive approach with histo- Tze Min Wah tripsy provides the potential to destroy targeted tissue without damaging non-targeted kidney tissue. Histotripsy’s purely mechanical mechanism of cellular destruction could preserve function of the kidney’s urine collecting system and eliminate certain complications seen with existing invasive approaches. Wah commented: “I was delighted to lead the clinical team in carrying out this world-first kidney tumour treatment using histotripsy and [it was] a real privilege to have the trust of the patient and Follow Renal their family in translating this innovative Interventions technology into our clinic. The CAIN Trial on all our represents a significant milestone for treatsocial media platforms ment of solid renal tumours with histofor the latest tripsy as a ‘needle-less’ technology. It is a news, insight paradigm shift.” and events in The platform used in the CAIN trial kidney care also provides physicians with the ability to monitor the destruction of tissue under continuous real-time visualisation and control. The trial is expected to support a future expansion of the indication to include the destruction of kidney tissue.
Transplantation updates page 10
Profile:
Neghae Mawla page 12
Regenerative material found “safe and feasible” for haemodialysis access in first-in-human study The advantages of autogenous fistulas to haemodialysis patients include long-term survival and low rates of complication. But failed or slow maturation as well as the risk of early thrombosis frequently “offset” these advantages and result in the use instead of a central venous catheter. Such “serious limitations”, write the authors of a new study published in the Journal of Vascular Access ( JVA), demand the evaluation of alternative options.
initial evaluation of [its] clinical safety and performance”. Patients were selected if they were aged 18–75, diagnosed with end-stage kidney disease (ESKD)—although one selected was pre-ESKD—and either on dialysis or intended to initiate it within 12 weeks. Primary efficacy endpoints of the study were primary patency, assisted primary patency, and secondary patency at 26 weeks, plus successful dialysis through to six months. Ultrasound and physical examination were used for assessment. Among the secondary endpoints was immune system response to the implant, while primary safety endpoints included freedom from clinically significant aneurysm and anastomotic bleeding. The authors state that the conduit “handled well surgimong those are biological regenerative cally, with properties similar to that of the native human conduits. Lead author Adrian Ebner (Sana- vein”. Conduit flow following the procedure was “exceltorio Italiano, Asuncion, Paraguay), along- lent in all cases,” meanwhile, “averaging 1098±388ml/min side fellow researchers including Haimanot at week four and remaining stable through 1248±355ml/min Wasse (Rush Medical College, Chicago, USA) at 26 weeks”. There was no significant change in surgiand corresponding author Zeeshan Syedain (University of cal site healing compared to regular conduits, with no oedema or erythema found at four weeks. Primary Minnesota, Twin Cities, USA), focused on the TRUE AVC patency at six months was found to be 80%, with (Vascudyne) tissue-engineered vascular conduit secondary patency recorded at 100%. There and examined whether it could demonstrate TRUE AVC was no infection in any of the patients, “functional patency, lack of infection, all of whom received dialysis, nor was and a low adverse event rate”. there statistically significant change in Ebner et al’s new study is among the diameter of the conduit on ultrathe first to focus on a novel tissue-ensound examination. The authors also gineered vascular conduit “cultured note that “no specific IgG antibody from completely biologic raw materesponse was seen in any patients”, rials and allogeneic dermal cells”, and add that one patient required reinwhich had previously been trialled in tervention for thrombus removal at non-human primate models. That trial five months. found no immune response, while Ebner and colleagues say the results “dialysis needle puncture sites demondemonstrate “the initial and early safety strated normal healing with no reduction of TRUE AVC”. Speaking exclusively to Renal in mechanical strength of the conduit”. This Interventions, Syedain added: “Completely biologstudy, meanwhile, follows on from the work of ical regenerative tissue conduits are designed to mimic Jeffrey H Lawson (Duke University, Durham, USA) and colleagues in a Lancet-published investigation from 2016, the structure and function of natural blood vessels, potenwhich found that a bioengineered human acellular vessel tially improving longevity and performance of haemo“seem[ed] to provide safe and functional haemodialysis dialysis grafts. This study demonstrates initial safety, access”, suggesting a potential step up from polytetrafluo- mechanical durability and lack of immune response with roethylene arteriovenous grafts and their associated throm- TRUE AVC, and its potential as an off-the-shelf blood vessel conduit for clinical use.” bosis and infection risks. Looking forward, Ebner et al point out that larger cohort Building on this, Ebner and colleagues designed their first-in-human study to look at the outcomes from five studies are planned to further investigate the safety and patients who received an implant of the conduit “in an efficacy of TRUE AVC.
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