Thrombolysis as a treatment for transplant renal artery thrombosis - a report of three unsuccessful cases and an overview of reported cases.

INTRODUCTION: Thrombolysis has been suggested as a feasible method to treat arterial renal transplant thrombosis under conditions of short duration of ischemia. Data on maximal duration of ischemia that are still feasible to treat are scarce. METHODS: We retrospectively analysed our experience involving three attempts to utilize thrombolysis to treat transplant renal artery thrombosis. We searched through literature on PubMed and compared the data we found with our own experience. RESULTS: In case number 1 of our cohort, thrombolysis was initiated 12 hours after the onset of thrombosis and had to be ceased after five hours due to the formation of a haematoma. Perfusion of the graft was restored but it did not regain function, most likely due to long ischemia time. In case number 2, an attempt to use thrombolysis was unsuccessful due to failure to cross the graft artery occlusion with a guidewire. Thrombosis was most likely caused by chronic rejection of the graft. In case number 3, thrombolysis restored arterial patency but, due to an onset of ischemia, which lasted 2 to 3 days, did not lead to restoration of graft function. The prolonged ischemia period in case three occurred, at least in part, due to failure to perform an ultrasound scan when the patient was first admitted. CONCLUSION: We can confirm that thrombolysis for transplant renal artery thrombosis seems to be feasible only when the condition has a short duration. In the event of sudden deterioration of graft function, the absence of perfusion must always be ruled out by ultrasound scan.

Renal sympathetic denervation in resistant arterial hypertension: long term and updated results.

The present paper is an extension to our earlier publication (Sochman et al. 2016) documenting a beneficial effect of renal sympathetic denervation on pharmacologically uncontrollable hypertension in a group of seven patients followed up for 1-2 years post-procedure. The same patients remained on ambulatory follow-up for another 5-6 years, with the beneficial effect persisting throughout the follow-up period while on the same medication.

Renal denervation in the most serious form of resistant arterial hypertension.

The aim of our observation was to establish whether or not renal sympathetic denervation (RSD) may help control blood pressure (BP) levels in patients with severe hypertension refractory to pharmacological therapy. Out of a group of 12 patients, candidates for RSD, with uncontrolled hypertension and a systolic BP over 190 mm Hg on repeated measurements despite optimal medication, four patients were excluded for multiple renal arteries and one for hyperaldosteronism. Seven patients had RSD using a Symplicity device (5M, 2 F) with a mean age of 64.9 years. While all were followed up for a minimum of 6 months, follow-up duration in the majority of them was substantially longer (12-20 months). At six months post-RSD, six of the seven patients showed a decrease in systolic BP by at least 15 mm Hg while receiving the same or fewer doses of antihypertensive agents. A similar response was seen in diastolic BP. The BP decrease was maintained throughout whole follow-up. In a small group of patients with severe hypertension, we demonstrated that renal sympathetic denervation is capable of reducing blood pressure even in patients with severe hypertension.

A comparison of portal vein embolization with poly(2-hydroxyethylmethacrylate) and a histoacryl/lipiodol mixture in patients scheduled for extended right hepatectomy.

To determine whether PHEMA [poly(2-hydroxyethylmethacrylate)] is suitable for portal vein embolization in patients scheduled to right hepatectomy and whether it is as effective as the currently used agent (a histoacryl/lipiodol mixture). Two groups of nine patients each scheduled for extended right hepatectomy for primary or secondary hepatic tumor, had right portal vein embolization in an effort to induce future liver remnant (FLR) hypertrophy. One group had embolization with PHEMA, the other one with the histoacryl/lipiodol mixture. In all patients, embolization was performed using the right retrograde transhepatic access. Embolization was technically successful in all 18 patients, with no complication related to the embolization agent. Eight patients of either group developed FLR hypertrophy allowing extended right hepatectomy. Likewise, one patient in each group had recanalization of a portal vein branch. Histology showed that both embolization agents reach the periphery of portal vein branches, with PHEMA penetrating somewhat deeper into the periphery. PHEMA has been shown to be an agent suitable for embolization in the portal venous system comparable with existing embolization agent (histoacryl/lipiodol mixture).

Reverse endoventricular artificial obturator in tricuspid valve position. Experimental feasibility research study.

The concept of vena contracta space reduction in tricuspid valve position was tested in an animal model. Feasibility of specific artificial obturator body (REMOT) fixed to the right ventricular apex and interacting with tricuspid valve leaflets was evaluated in three different animal studies. Catheter-based technique was used in three series of experiment in 7 sheep. First acute study was designed for evaluation if the screwing mode of guide wire anchoring to the right ventricular apex is feasible for the whole REMOT body fixing. Longer study was aimed to evaluate stability of the REMOT body in desired position when fixing the screwing wire on its both ends (to the right ventricular apex and to the skin in the neck area). X-ray methods and various morphological methods were used. The third acute study was intended to the REMOT body deployment without any fixing wire. In all of 7 sheep the REMOT was successfully inserted into the right heart cavities and then fixed to the right ventricular apex area. When the REMOT was left in situ more than 6 months it was stable, induced adhesion to the tricuspid valve leaflet and was associated with a specific cell invasion. Releasing of the REMOT from the guiding tools was also successfully verified. Deployment of the obturator body in the aim to reduce the tricuspid valve orifice is feasible and well tolerated in the short and longer term animal model. Specific cell colonization including neovascularization of the obturator body was observed.

Restoration of failed renal graft function after successful angioplasty of pressure-resistant renal artery stenosis using a cutting balloon: a case report.

This study is the report of a 37-year-old male with a transplanted kidney from a 3.5-year-old donor: the graft had two arteries transplanted with an aortic patch to an external iliac artery. Four months after transplantation, the graft function deteriorated, together with the development of hypertension. Stenosis of both graft arteries was detected and the patient was referred for angioplasty. The angiographic result was suboptimal, nevertheless, the graft function improved and was more or less stable (serum creatinine, 160-200 micromol/l) for 4 years, along with persistently difficult-to-control hypertension. Five years after transplantation, the graft function deteriorated again and severe graft artery restenosis was detected. The restenosis did not respond to dilatation, graft function failed, hypertension decompensated, and left ventricular failure developed. The patient required dialysis. A cutting balloon angioplasty opened the artery, and kidney function was restored after a few days: the serum creatinine level dropped to 140-160 micromol/l, and the glomerular filtration rate (creatinine clearance) to 0.65 ml/min/1.73 m(2). The graft function has now been stable for more than 2 years, however, the hypertension is still difficult to control.

Self-expandable stent placement in infrapopliteal arteries after unsuccessful angioplasty failure: one-year follow-up.

The purpose of this prospective study was to evaluate whether stent placement in infrapopliteal arteries is helpful in failed percutaneous transluminal angioplasty (PTA). Infrapopliteal PTA was performed in 70 arteries of 66 patients with chronic critical lower limb ischemia. The group comprised 55 males and 11 females, with an average age of 63.4 (range, 42-82) years. Diabetes mellitus was present in 92.4% of patients. Only the palpable anterior tibial and posterior tibial arteries were evaluated. Stents (Xpert stent; Abbot Vascular, Redwood City, CA, USA) were placed in 16 arteries where PTA was not successful (the failure was defined as residual stenosis >30% after PTA). In 54 arteries simple PTA was performed and was technically successful. Twenty-four nondilated arteries with no significant stenosis served as a comparison group. The 12-month patency rate was evaluated according to a combination of palpation and Doppler ultrasound. In all cases stent placement restored the flow in the artery immediately after unsuccessful PTA. Twelve-month follow-up showed a patency rate of 82% in the PTA group, 78% in the stent group, and 69% in the comparison group. We conclude that stent placement in the case of unsuccessful infrapopliteal PTA changed technical failure to success and restored flow in the dilated artery. At 12-month follow-up the patency rate of infrapopliteal arteries stented for PTA failure did not differ significantly either from nonstented arteries with an optimal PTA result or from a comparison group of nonintervened arteries.

Catheter-based management of aortic valve regurgitation in experimental cardiology.

Non-surgical management of aortic valve disease has been given considerable attention. Several recent publications have already reported its use in clinical practice. The main issue is to get an understanding of the pathophysiological processes and, most importantly, extensive experimental activity. In addition to testing various animal models, technical and material aspects are also being intensively investigated. It is not clear yet whether the durability and applicability of this promising development will be comparable with the standard of current cardiac surgery. Nonetheless, even the use of some models as a temporary approach helping to improve the circulatory status, not allowing safe surgery, is certainly justified. At any rate, a new stage of research and clinical application has been set off. However, experimental background continues to be simply indispensable. The paper is a short review of the issue.

Percutaneous transcatheter aortic disc valve prosthesis implantation: a feasibility study.

PURPOSE: Over the past 30 years there have been experimental efforts at catheter-based management of aortic valve regurgitation with the idea of extending treatment to nonsurgical candidates. A new catheter-based aortic valve design is described. METHODS: The new catheter-delivered valve consists of a stent-based valve cage with locking mechanism and a prosthetic flexible tilting valve disc. The valve cage is delivered first followed by deployment and locking of the disc. In acute experiments, valve implantation was done in four dogs. RESULTS: Valve implantation was successful in all four animals. The implanted valve functioned well for the duration of the experiments (up to 3 hr). CONCLUSION: The study showed the implantation feasibility and short-term function of the tested catheter-based aortic disc valve. Further experimental studies are warranted.

Mechanical thrombolysis of thrombosed hemodialysis native fistulas with use of the Arrow-Trerotola percutaneous thrombolytic device: our preliminary experience.

PURPOSE: To evaluate the feasibility of use of the Arrow-Trerotola percutaneous thrombolytic device (PTD) in the treatment of thrombosed hemodialysis native fistula occlusions. MATERIALS AND METHODS: Ten patients with native fistula occlusion underwent mechanical thrombolysis with use of the PTD. The standard PTD was used in seven patients and the over-the-wire device was used in three patients. Major outcomes of our study included procedure time, clinical success, complication rate, and 3- and 6-month patency rates. RESULTS: The technical success rate was 100% and the clinical success rate was 90% (9 of 10). In all 10 cases, the procedure was associated with angioplasty. There were no major complications. The mean time of successful procedures was 126.1 minutes. The 3- and 6-month primary patency rates were 70% and 60%, respectively; the assisted primary patency rate at 6 months was 80%. CONCLUSION: The PTD is an effective mechanical device for percutaneous treatment of thrombosed hemodialysis access. Our clinically successful initial experience with the PTD shows that the technique is rapid and safe for treatment of native fistula occlusions.

Evaluating the outcome of percutaneous transluminal angioplasty in renal graft artery stenosis using the areas under the time curve of glomerular filtration rate and blood pressure.

The benefit of percutaneous transluminal angioplasty (PTA) of transplant renal artery stenosis for ischemic nephropathy may be adversely affected by rejection or other complications. As a result, assessment of the effect of PTA on renal function or blood pressure is often difficult. In this paper, we evaluated the effect of PTA using the method of integrated glomerular filtration rate (GFR) based upon the area under the curve over a follow-up period (AUC0-1), to express the level of GFR in a simple manner despite its significant fluctuations. A similar procedure was used to evaluate mean arterial pressure (MAP). The method was employed to assess the outcome in 20 individuals before PTA, and 1, 3, 6, 9 and 12 months after PTA. In eight cases, rejection was detected while there was one case of glomerulonephritis in the graft during the follow-up period. Evaluation (AUCCcr)0-12 related to the integrated pre-PTA value of Ccr [(Ccr)0 x 12] revealed a rise in GFR by more than 20 % in 65 % of cases. No improvement was observed in seven individuals with post-PTA complications. When assessing the integrated value of MAP, success of PTA (a reduction by at least 10 %) was found in 85 % of cases. No significant correlation was found between the relative changes of integrated GFR and MAP. Our data suggest that evaluation of the integrated value of GFR or MAP on the basis of AUC0-t allows to characterize, in a simple manner, the level of graft function and MAP throughout the follow-up period in individual cases. Furthermore, it may provide additional information on the average values obtained at different time intervals after the therapeutic procedure.

[Evaluation of the results of percutaneous transluminal angioplasty of arterial stenosis in the transplanted kidney using area under time curves of the glomerular filtration rate and blood pressure]. / Hodnocení výsledku perkutánní transluminální angioplastiky pri stenóze tepny transplantované ledviny na podklade ploch pod casovou krivkou glomerulární filtrace a krevního tlaku.

The benefit of percutaneous transluminal angioplasty (PTA) of renal transplant artery stenosis for renal hemodynamics is frequently adversely affected by rejection or another complication. As a result, evaluation of the effect of PTA is often difficult. Our study was designed to assess the effect of PTA using a method of integrated value of the glomerular filtration rate (GFR) calculated on the basis of the area under the curve over the follow-up period (AUC0-t). A similar procedure was employed to evaluate mean arterial pressure (MAP). The method was used to assess the outcome in 20 individuals before to PTA, and at 1, 3, 6, 9 and 12 months after angioplasty. A rejection episode was diagnosed in eight cases and glomerulonephritis of the graft in one. Using the evaluation of (AUCCcr)0-12 in relation to the integrated value before PTA (Ccr) x 12, a rise in GFR > 20% was found in 65% of cases. PTA failure was observed in seven individuals developing post-PTA complications. When assessing the integrated value of MAP, PTA was found to be successful (a reduction by at least 10%) in 85% of cases. No significant correlation was demonstrated between the integrated values of GFR and MAP. The results support the assumption that the evaluation of the integrated values of GFR or MAP using AUC0-t allows to characterize, in a simple manner, the degree of renal transplant function or MAP throughout the follow-up period, and to furnish additional information to the values obtained at individual time intervals after the therapeutic procedure.

[Percutaneous transluminal angioplasty of the renal artery in transplanted kidneys]. / Perkutánní transluminální angioplastika tepny transplantované ledviny.

UNLABELLED: The objective of the work was to evaluate the contribution of percutaneous transluminal angioplasty (PTA) to treatment of hypertension and the graft function of a transplanted kidney. Angioplasty of the graft artery was performed in 39 patients. Technical success rate: 85%. COMPLICATIONS: 13%--in particular during the first years after introduction of the method. Twenty seven patients were followed up on a long-term basis. Changes of the median arterial pressure (MAP) were evaluated as well as glomerular filtration (GF) assessed by creatinine clearance. Mean values: [table: see text] A statistically significant (p < 0.01) reduction of the median arterial pressure (drop by > 10 mm Hg) along with reduction of the number of antihypertensive drugs was recorded in 70% of the patients during the first year and in 80% kidney recipients in investigations extending beyond one year. A significant increase of glomerular filtration (by > 20%) was found in 40% of the patients, on average the rise was insignificant. During the follow up period 13 kidney recipients were transferred to a dialyzation programme due to failure of the grafts as a result of rejection. CONCLUSION: Percutaneous transluminal angioplasty of a stenosis of the graft artery is the method of first choice in the treatment of hypertension. It is of fundamental importance also in rare cases in order to preserve or improve graft function and thus delay dialyzation treatment.

Temporary balloon closure of a postinfarction interventricular septal rupture.

The technical aspects of temporary closure of a postinfarction interventricular septal rupture in a 76-year-old woman in critical circulatory status ruling out conservative therapy and making surgical management unfeasible, are described. The patient was in cardiogenic shock with hepatorenal failure in acute myocardial infarction of both the anterior and posterior walls. A balloon catheter developed in our unit was employed to close the rupture.

Long-term control of hypertension and the predictive value of peripheral plasma renin activity after ablation of end stage kidneys with a new embolic agent.

Embolization of end-stage kidneys using our own embolizing agent Vilanol (partially hydrolyzed polyvinyl acetate) was performed in 10 patients with hypertension refractory to conservative therapy. Native kidneys were embolized in 7 patients with chronic renal failure, nonfunctioning renal transplants in 2 patients, and a shrunken kidney in 1 patient. Five of the 10 patients had high (9.96-18.2 ng/ml/h) peripheral renin (PR) levels. The embolization was technically successful in 4 of these 5 patients and was immediately followed by a marked decrease in PR, and simultaneous improvement in blood pressure (BP). The other 5 patients had very low PR levels (0.07-0.65 ng/ml/h), and a reduction in BP was observed in 4 after embolization. One patient died following embolization from cardiac arrest due to hyperkalemia. Six patients (3 in each group) have been on follow-up for 2-5 years with sustained decrease in BP. We conclude that the new agent is effective for renal ablation and control of refractory hypertension.

Detachable balloon embolization of an iatrogenic aortocoronary arteriovenous fistula combined with aortocoronary bypass PTCA: a case report.

Coronary artery bypass surgery was performed in a 54-year-old male, and one of the grafts was inadvertently sutured to the vena cordis magna instead of to the left anterior descending coronary artery (LAD). Four years later the patient observed a progression of symptoms including episodes of angina pectoris at rest. Coronary angiography showed stenosis of one of the bypass grafts and notable dilatation of an iatrogenic arteriovenous (A-V) fistula. The stenosed bypass graft was dilated and the A-V fistula occluded by use of a detachable balloon. Embolization was performed rather than surgery, as the LAD was found to be a poor surgical target. The patient's symptoms improved after the procedure; he was followed for 18 months during which time his condition remained stable.

Total recovery of left ventricular function after acute myocardial infarction: comprehensive therapy with streptokinase, N-acetylcysteine and percutaneous transluminal coronary angioplasty.

In this report we describe our first use of N-acetylcysteine in a patient with his first acute myocardial infarction in an effort to reduce the infarct size and to protect left ventricular function by pharmacological and mechanical therapy (thrombolysis and percutaneous transluminal coronary angioplasty). This comprehensive therapy caused normalization of previously depressed left ventricular systolic function.