Portal hypertension after combined liver and intestinal transplantation, a diagnostic and therapeutic challenge?

A widely accepted technique to transplant the liver-bowel bloc is first to perform a piggyback anastomosis of the donor suprahepatic vena cava to the recipient vena cava; second to restore the arterial blood supply through an aortic interposition graft; and third to ensure venous drainage of the native foregut. The venous drainage of the native foregut can be restored through an end-to-end portocaval anastomosis between the donor infrahepatic vena cava and the recipient portal vein. Stenosis of this anastomosis can lead to portal hypertension presenting with upper GI congestion, bleeding, and hypersplenism. We report the successful treatment of this complication using an e-PTFE-covered stent inserted following balloon angioplasty

A Comparison of CVR Magnitude and Delay Assessed at 1.5 and 3T in Patients With Cerebral Small Vessel Disease

BACKGROUND: Cerebrovascular reactivity (CVR) measures blood flow change in response to a vasoactive stimulus. Impairment is associated with several neurological conditions and can be measured using blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI). Field strength affects the BOLD signal, but the effect on CVR is unquantified in patient populations. METHODS: We recruited patients with minor ischemic stroke and assessed CVR magnitude and delay time at 3 and 1.5 Tesla using BOLD MRI during a hypercapnic challenge. We assessed subcortical gray (GM) and white matter (WM) differences using Wilcoxon signed rank tests and scatterplots. Additionally, we explored associations with demographic factors, WM hyperintensity burden, and small vessel disease score. RESULTS: Eighteen of twenty patients provided usable data. At 3T vs. 1.5T: mean CVR magnitude showed less variance (WM 3T: 0.062 ± 0.018%/mmHg, range 0.035, 0.093; 1.5T: 0.057 ± 0.024%/mmHg, range 0.016, 0.094) but was not systematically higher (Wilcoxon signal rank tests, WM: r = −0.33, confidence interval (CI): −0.013, 0.003, p = 0.167); delay showed similar variance (WM 3T: 40 ± 12 s, range: 12, 56; 1.5T: 31 ± 13 s, range 6, 50) and was shorter in GM (r = 0.33, CI: −2, 9, p = 0.164) and longer in WM (r = −0.59, CI: −16, −2, p = 0.010). Patients with higher disease severity tended to have lower CVR at 1.5 and 3T. CONCLUSION: Mean CVR magnitude at 3T was similar to 1.5T but showed less variance. GM/WM delay differences may be affected by low signal-to-noise ratio among other factors. Although 3T may reduce variance in CVR magnitude, CVR is readily assessable at 1.5T and reveals comparable associations and trends with disease severity

Failed surgical ligation of the proximal left subclavian artery during hybrid thoracic endovascular aortic repair successfully managed by percutaneous plug or coil occlusion: a report of 3 cases

Open surgical rerouting and proximal ligation of one or more supra-aortic vessels prior to endovascular stent-graft placement has become an alternative to major open thoracic surgery in the treatment of complex thoracic aortic disease. Complications owing to failed surgical ligation of the left subclavian artery are rare. In this report, 3 cases of failed ligation are presented. Diagnosis was made by CT-scan and treatment was performed by transcatheter coil and plug embolization, avoiding redo neck surgery

Kliničke praktične smjernice za perioperacijsku i poslijeoperacijsku skrb o arterijsko-venskim fistulama i umetcima za hemodijalizu u odraslih

Krvožilni pristup omogućuje hemodijalizu koja spašava život. Stoga je nužna dobra funkcija krvožilnog pristupa koja omogućuje prikladan krvni protok radi uklanjanja tvari koje se u uremiji zadržavaju u krvi bolesnika, uz istodobno sniženje rizika od sustavne infekcije na najmanju moguću mjeru. Godine 2007. Europske smjernice najbolje prakse (engl. European Best Practice Guidelines – EBPG), prethodnice trenutačne Europske najbolje bubrežne prakse (engl. European Renal Best Practice – ERBP), donijele su nacrt skupine preporuka – vodiča pri donošenju odluka o upućivanju na pregled radi krvožilnog pristupa, o procjeni i nadzoru izbora pristupa te o postupcima kod komplikacija. (1) Otad su se znatno razvili ne samo dokazi na kojima se temelje ove preporuke nego i procesi nastajanja smjernica. (2) Kao odgovor na to, ERBP je ažurirao prethodno djelo u suradnji s raznim stručnjacima iz tog područja uključujući i predstavnike Društva za krvožilni pristup (engl. Vascular Access Society – VAS), kirurge za krvožilni pristup, radiologe, medicinske sestre za dijalizu, znanstvenike, bolesnike i one koji se za njih brinu. Nastojanje da se pridržavaju sve strože metodike izrade smjernica nalagalo je određena odricanja u pogledu područja obuhvata ovih smjernica. Posljedično, one ne „pokrivaju” baš sve iste teme kao njihova prethodna verzija. Neka su područja zajednička, a neka su arhivirana da bi ustupila mjesto novim pitanjima kojima su prednost dali i pružatelji zdravstvene skrbi i oni za koje se skrbi. Odvojeno su objavljene pojedinosti postupka izbora djelokruga problematike koju su smjernice obuhvatile. (3) Nastajanje ovih smjernica slijedilo je strog proces pregleda i procjene dokaza koji se temeljio na sustavnim pregledima rezultata kliničkih istraživanja te opservacijskih podataka gdje je to bilo potrebno. Strukturirani pristup slijedio je model sustava GRADE (hrv. stupanj), koji svakoj preporuci pripisuje stupanj s obzirom na sigurnost sveukupnih dokaza te snagu. (4) Gdje je to bilo primjereno skupina za izradu smjernica unijela je nestupnjevan savjet za kliničku praksu, a koji nije proistekao iz pregleda sustavnih dokaza. Kliničke praktične smjernice iz 2019. godine specifično pokrivaju peritransplantacijske i poslijetransplantacijske aspekte arterijsko-venskih (AV) fistula i umetaka (graftova). Drugi dio, koji je bio u nastajanju kada su ove smjernice išle u tisak, pokrit će aspekte izbora krvožilnog pristupa, prijeoperacijske procjene krvnih žila i središnje venske katetere. Unatoč nedostatku dokaza velike sigurnosti za većinu područja krvožilnih pristupa, ERBP se posvetio izradi smjernica velike kakvoće, dajući smjernicu gdje god je moguće, a popis preporuka za istraživanje ondje gdje se nije moglo uputiti smjernicom. Nadamo se da će ove smjernice i one planirane pomoći stručnoj zajednici pri donošenju odluka o postupcima, postupnicima i skrbi vezanima s krvožilnim pristupima, pomoći bolesnicima i onima koji se za njih brinu da steknu uvid u problematiku te olakšati zajedničko donošenje odluka u tom području

Diagnostic and percutaneous interventional techniques for prevention and treatment of dysfunctional hemodialysis fistulas and grafts

The aim of this thesis was to evaluate different diagnostic and interventional radiological techniques to prevent and to treat the most common problems in hemodialysis arteriovenous fistulas (AVF) and arteriovenous grafts (AVG). Most important problems for AVF and AVG are non-maturation after surgical access creation almost exclusively for AVF, with a primary failure rate ranging between 19% and 43% and dysfunction because of stenosis or thrombosis for both AVF and AVG. In chapter 3 and 4 the role of carbon dioxide (CO2), a non-nephrotoxic and non-allergic gas used as an alternative intravascular contrast medium to iodinated contrast material was studied in preoperative venous mapping. In chapter 3 CO2 has been compared to iodine in upper limb venography. CO2 venography had good interobserver agreement (=0.90), comparable to interobserver agreement for conventional venography (=0.96) and an accuracy, sensitivity and specificity of 95%, 97% and 85% respectively. These results showed that venography with CO2 is an acceptable alternative to conventional venography with iodine, the latter harboring a potential risk of further impairment of renal function when used in patients with chronic kidney disease (CKD). In chapter 4 the impact of CO2 venography on the creation and outcome of AVF was examined in patients without suitable veins on clinical examination. CO2 venography allowed identification of veins amenable for AVF creation. AVF (21 forearm AVF, 80 proximal forearm or elbow AVF) was created in 77% of the patients. Vascular access surgery corresponded with the findings of CO2 venography in 90% of cases. In 8 cases access creation was attempted with a vein considered not suitable on CO2 venography; maturation rate of these cases was significantly lower compared to the maturation rate of the AVF created with suitable veins on CO2. Overall maturation rate of the AVF created was 83.5% with patency rates comparable to other studies on vascular mapping such as duplex ultrasound (US).The diagnostic accuracy of multidetector computed tomography (MDCT) angiography to detect a stenosis ≥ 50% or occlusion in dysfunctional AVF compared to digital subtraction angiography (DSA) was evaluated in chapter 5. Interobserver agreement was excellent for both DSA (=0.86) and MDCT angiography (=0.82). Accuracy, sensitivity, specificity, positive predictive value and negative predictive value for MDCT angiography to detect a stenosis ≥ 50% or occlusion was high. Image quality of MDCT angiography was graded as good or excellent with adequate information in 97.2% of cases. No significant difference in image quality was seen between MDCT angiography and DSA or between MDCT angiography with the patient s arm stretched overhead or alongside the body. These results demonstrated that MDCT angiography is a reproducible and reliable technique to detect significant stenosis/occlusion in dysfunctional AVF, with good image quality.In chapter 6, the aim of the study was to determine variables that were predictors of outcome (technical success, dysfunction recurrence and patency) after percutaneous transluminal balloon angioplasty (PTA) in de novo AVF. Technical success was significantly higher in radiocephalic AVF compared to proximal forearm AVF and was negatively correlated with initial stenosis (the higher the initial stenosis grade, the smaller the probability of technical success). Dysfunction recurrence occured in 52.7% and was negatively correlated with technical success and AVF age. Thus technical success of PTA in virgin AVF is affected by AVF type and initial stenosis grade and has an effect on dysfunction recurrence, but not on AVF longevity (no difference in secondary patency). Early dysfunction (dysfunction within 6 months) was negatively correlated with AVF age and positively correlated with diabetes mellitus. Higher AVF age resulted in higher primary and secondary patency rates. Treatment of a thrombosed access (AVF and AVG) by pharmacomechanical means using a brush-catheter and a thrombolytic agent was evaluated in chapter 7. The mean procedure time was 99.2 minutes, and was significantly higher in AVF than in AVG. Anatomic success rate was 100%, clinical success rate was 96.2%. No major complications were seen, while minor complications occurred in 8% of the procedures. Patency rates after one year were acceptable, especially for AVF. In chapter 8 the operator radiation dose during percutaneous interventions on AVF and AVG was examined. Correlation between DAP and radiation dose measured at the hands, legs and eye lens was weak to moderate. Radiation exposure to the hands was significantly higher compared to the legs. In recanalization procedures radiation dose were significantly higher at the hands and at the left leg. Radiation dose was higher to the left hand and leg in interventions on a right-sided access and vice versa. Radiation dose to the eye lens may be higher in systems quipped with a flat-panel detector system versus image intensifier system. In general, operator radiation exposure to the hands, legs and eye lens is relatively low. Recanalization procedures result in higher dose to the hands and left leg. The position of the hands tot the X-ray tube is the main determinant for the dose.Diagnostic and interventional radiology has an important role in the prevention of hemodialysis access dysfunction by providing reliable vascular mapping techniques such as CO2 venography, but also in demonstrating underlying stenosis or thrombosis in a dysfunctional access. (Interventional) Radiology is mandatory in access maintenance and in identifying variables that may influence outcome of the interventional procedure. The potential hazards of ionizing radiation during the interventional procedures are relatively low, yet should be taken into account.nrpages: 216status: publishe

Failed surgical ligation of the proximal left subclavian artery during hybrid thoracic endovascular aortic repair successfully managed by percutaneous plug or coil occlusion: a report of 3 cases

Abstract Open surgical rerouting and proximal ligation of one or more supra-aortic vessels prior to endovascular stent-graft placement has become an alternative to major open thoracic surgery in the treatment of complex thoracic aortic disease. Complications owing to failed surgical ligation of the left subclavian artery are rare. In this report, 3 cases of failed ligation are presented. Diagnosis was made by CT-scan and treatment was performed by transcatheter coil and plug embolization, avoiding redo neck surgery.</p