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.

Evaluation of later morphologic alterations in renal artery wall and renal nerves in response to catheter-based renal denervation in sheep: comparison of the single-point and multiple-point ablation catheters.

This study evaluated the subacute morphologic alterations in renal artery wall and renal nerves in response to catheter-based renal denervation (RDN) in sheep and also compared the efficiency of single-point and multiple-point ablation catheters. Effect of each ablation catheter approved for the clinical use (Symplicity Flex(TM), Medtronic, Inc., or EnligHTN(TM), St. Jude Medical, INC.) was compared to intact contralateral renal artery in 12 sheep by histopathology and immunohistochemistry evaluation after a 10-day period post-RDN procedure. The safety was verified by extensive evaluation of kidney morphology. Vascular wall lesions and nerve injuries were more pronounced in those animals treated with multi-point EnligHTN catheter when compared with animals treated with single-point Symplicity Flex catheter. However, neither RDN procedure led to complete renal nerve ablation. Both systems, tested in the present study, provided only incomplete renal nerve ablation in sheep. Moreover, no appreciable progression of the nerve disintegration in subacute phase post-RDN procedure was observed. This study further supports the notion that the effectiveness remains fully dependent on anatomical inter-individual variability of the sympathetic nerve plexus accompanying the renal artery. Therefore, new systems providing deeper penetrance to targeted perivascular structure would be more efficient.

Early morphologic alterations in renal artery wall and renal nerves in response to catheter-based renal denervation procedure in sheep: difference between single-point and multiple-point ablation catheters.

Renal sympathetic hyperactivity is critically involved in hypertension pathophysiology; renal denervation (RDN) presents a novel strategy for treatment of resistant hypertension cases. This study assessed effects of two RDN systems to detect acute intravascular, vascular and peri-vascular changes in the renal artery, and renal nerve alterations, in the sheep. The procedures using a single-point or multi-point ablation catheters, Symplicity Flex(TM), Medtronic versus EnligHTN(TM), St. Jude Medical were compared; the intact contralateral kidneys served as controls. Histopathological and immunohistochemical assessments were performed 48 h after RDN procedures; the kidney and suprarenal gland morphology was also evaluated. Special staining methods were applied for histologic analysis, to adequately score the injury of renal artery and adjacent renal nerves. These were more pronounced in the animals treated with the multi-point compared with the single-point catheter. However, neither RDN procedure led to complete renal nerve ablation. Forty-eight hours after the procedure no significant changes in plasma and renal tissue catecholamines were detected. The morphologic changes elicited by application of both RDN systems appeared to be dependent on individual anatomical variability of renal nerves in the sheep. Similar variability in humans may limit the therapeutic effectiveness of RDN procedures used in patients with resistant hypertension.

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.

Biliary strictures after orthotopic liver transplantation: long-term results of percutaneous treatment in patients with nonfeasible endoscopic therapy.

PURPOSE: The aim of this study was to evaluate our experience with percutaneous treatment of biliary strictures after orthotopic liver transplantation in adult patients without the endoscopic access possibility and to evaluate the technical outcomes and long-term clinical results of this treatment. MATERIALS AND METHODS: Thirty percutaneous procedures were performed in adult liver transplant recipients (13 men, 17 women, mean age 46.4 years) in our institution between 1996 and 2010. Patients were treated with balloon dilatation and biliary duct drainage due to anastomotic stenosis (n = 20), nonanastomotic stenosis (n = 7), or due to stenosis caused by lymphoproliferation (n = 3). The percutaneous procedure was the first line of treatment due to hepaticojejunoanastomosis (n = 18) or after unsuccessful endoscopic therapy (n = 12). RESULTS: Technical success was achieved in 27 patients (90%). The remaining three patients only achieved external drainage with subsequent surgery. There were two complications (6.3%). Long-term clinical success, defined as the absence of clinical, laboratory, or sonographic signs of stricture recurrence was achieved in 22 patients (73.3%) for a mean follow-up of 5.8 years. CONCLUSION: Percutaneous treatment--balloon dilatation and biliary duct drainage--is a first-line option to manage biliary duct strictures in liver recipient, when endoscopic treatment is not possible or unsuccessful. It has a high technical success rate and low complication rate with favorable long-term results.

[Early biliary complications following liver transplantation]. / Casné biliární komplikace po transplantaci jater.

INTRODUCTION: Biliary complications (BC) after liver transplantation (LTx) are serious problems with an incidence rate of 6-35%. There are two types of BC, early and late. Early BC is observed for 30 days post LTx or during the entire period of the patient's first hospital stay after LTx. The main causes of early BC are ischemia of the biliary tree (the bile duct of the transplanted liver is supplied only from the right hepatic artery descendingly; the supply from the gastroduodenal artery is lacking) as well as implementation of the biliary anastomosis surgical technique. Treatment of BC is administered by a surgeon, a gastroenterologist and a radiologist. AIM: To evaluate early biliary complications after LTx PATIENTS AND METHODS: We reviewed patients with early BC after LTx from 4/2004 - 12/2009. We defined early BC as a complication that is present during the first 30 days post LTx or during the entire period of the patient's first hospital stay after LTx. RESULTS: We performed 384 LTx during the above-mentioned period. We carried out reconstruction of the biliary tree in the form of a choledochocholedochostomy (CDD) in 312 cases and in the form of a choledochojejunostomy (CDJ) in 72 cases. Sixty-eight patients had early BC (17.7%), 25 patients experienced biliary leak (6.5%), 40 patients had anastomotic stenosis (10.4%) and 3 patients (0.8%) experienced both complications (biliary leak and stenosis). Most complications were eliminated by ERCP with a papilosfincterotomy, a balloon dilatation of stenosis, and a biliary stent implant with repeated stent replacements (45 cases in total- all patients with biliary stenosis). Twenty-two patients were reoperated on (16x CDJ, 3x re-CDD, 2x suture of aberrant bile duct, 1x suture common bile duct) and 1 patient was treated by percutaneous transhepatic bilary drainage (PTD). The mortality rate was zero. CONCLUSION: BC after LTx continue to pose a serious surgical problem. The treatment of choice when dealing with BC is ERCP, which has more than a 70% success rate. If ERCP or PTD are not successful, or when biliary peritonitis is present, we perform a reanastomosis of the bile duct. The combined effort of the surgeon, gastroenterologist and radiologist is the most important factor for successful treatment. The incidence of BC after LTx at IKEM is similar to that of treatment centers all over the world.

New insights on the mechanism of oxidation of D-galacturonic acid by hypervalent chromium.

The pollutant Cr(VI) is known to be very carcinogenic. In conditions of excess of Cr(VI), oxidation of D-galacturonic acid (Galur), the major metabolite of pectin, yields d-galactaric acid (Galar) and Cr(III). The redox reaction takes place through a multistep mechanism involving formation of intermediate Cr(II/IV) and Cr(V) species. The mechanism combines one- and two-electron pathways for the reduction of Cr(IV) by the organic substrate: Cr(VI)→ Cr(IV)→ Cr(II) and Cr(VI)→ Cr(IV)→ Cr(III). This is supported by the observation of the optical absorption spectra of Cr(VI) esters, free radicals, CrO(2)(2+) (superoxoCr(III) ion) and oxo-Cr(V) complexes. Cr(IV) cannot be directly detected; however, formation of CrO(2)(2+) provides indirect evidence for the intermediacy of Cr(II/IV). Cr(IV) reacts with Galur much faster than Cr(V) and Cr(VI) do. The analysis of the reaction kinetics via optical absorption spectroscopy shows that the Cr(IV)-Galur reaction rate inversely depends on [H(+)]. Nevertheless, high [H(+)] still does not facilitate accumulation of Cr(IV) in the Cr(VI)-Galur mixture. Cr(VI) and the intermediate Cr(V) react with Galur at comparable rates; therefore the build-up and decay of Cr(V) accompany the decay of Cr(VI). The complete rate laws for the Cr(VI), Cr(V) and Cr(IV)-Galur redox reaction are here derived in detail. Furthermore, the nature of the five-co-ordinated oxo-Cr(V) bischelate complexes formed in Cr(VI)-Galur mixtures at pH 1-5 is investigated using continuous-wave and pulsed electron paramagnetic resonance (EPR) and density functional theory (DFT).

[Transarterial chemoembolization in hepatocellular carcinoma]. / Transarteriální chemoembolizace u hepatocelulárního karcinomu jater.

INTRODUCTION: Hepatocelullar carcinoma (HCC) is the fifth most common cancer in the world. It mostly occurs in patients with cirrhosis. In the Czech Republic, about 250 new cases are reported per year. Surgery, i.e. liver resection or transplantation, as the only potentially curable method is possible in 15-20% of them. For the rest, palliative treatment is indicated. This includes ablative methods (radiofrequency ablation, alcoholization), transarterial chemoembolization (TACE), systemic chemotherapy or biological treatment by sorafenib. TACE is method of choice in patients unsuitable for surgery and ablative treatment. Another indication is embolization of HCC before liver transplantation to prevent tumour progression. In combination with other methods, down staging of the tumour and curable treatment afterward is possible. AIMS: To assess the outcome of transarterial chemoembolisation in patients with hepatocellular carcinoma. METHODS: Between 2004-2008 we performed 30 TACE. Of that number, 28 TACE were performed in 20 patients with HCC. We super selectively catheterized the tumour via arteria femoralis and used Doxorubicin with Lipiodol as embolic material. In follow up, we carried out laboratory studies and CT. RESULTS: We have not noticed any major complications. Post-embolization syndrome with fever, nausea and right upper quadrant pain occurred after 10 TACE (33%). One-, two- and three years survival of the patients was 53%, 40% a 20%. CONCLUSION: TACE is safe method prolonging patients' survival with unresectable HCC. For the correct treatment of HCC, its concentration to cancer centres and the cooperation between multiple specialists is necessary.

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.

[Vascular complications after pancreatic transplantation]. / Cévní komplikace po transplantaci pankreatu.

Transplantation of pancreas is presently the only way of treating diabetes of the 1st type, capable to secure a long-term normoglycemia. In spite of the fact that the surgical technique and tactics of the whole intervention has been standardized over the last years, surgical complications and more specifically vascular complications still pose a certain risk of the graft loss. The thrombosis of vessels of the transplanted pancreas occurred in our group in 4.1 per cent of cases. The other rare complications included a false aneurysm of the supplying artery and stenosis of the out-coming vein from the pancreatic graft. Both these complications were successfully treated by a radio-invasive approach. A refinement of the surgical technique and the introduction of new immunosuppressive drugs manifests favorably in decreasing occurrence of vascular complications after the transplantation of pancreas.

[Corneal surface analysis]. / Analýza povrchu rohovky.

Fourier analysis is a powerful method of evaluating the surface of the cornea. In 50 patients after photorefractive keratectomy included in our study we measured spherical equivalent, regular astigmatism, irregular astigmatism and decentration retrospectively acquired by Fourier series analysis of corneal topography data 1, 3, 6 and 12 months after operation. Postoperative decentration increased significantly from a mean preoperative value. The preoperative and postoperative values are not significantly different. The Fourier spherical equivalent and the values of keratometric spherical (equivalent) are highly correlated. Correlation among decentration, irregular astigmatism and best corrected visual acuity is important for clinical practice. Due to Fourier analysis we obtain information, which could explain worse results of some surgeries.

[Optic disc pits and maculopathy (electroretinography study)]. / Jamky terce a makulopatie (Elektroretinografická studie).

An ERG examination according to the international standard was made in 55 patients with pits in the optic nerve disc. 19 of them suffered from concurrent maculopathy. Electroretinography revealed in scotopic responses a significant reduction of amplitudes of oscillatory potentials and reduction of potentials of the b wave in standard (maximal) reactions. Even more markedly the cone reactions and flicker were reduced--responses to intermittent (30 Hz) photostimulation. The authors consider maculopathies with pits a separate nosological unit with possible hereditary transmission. ERG signalizes a more extensive alteration of retinal structures than affection of the centre, probably on the basis of the circulation. Maculopathies with pits are also characterized by the fact that the dramatic drop of amplitudes is associated with the patient's age or the duration of the disease.

[Effect of YAG capsulotomy of secondary cataracts on visual functions]. / Vliv YAG kapsulotomie u sekundární katarakty na zrakové funkce.

1. 20 patients (20 eyes) with secondary cataract and best corrected visual acuity (BCVA) of 20/30 or 20/20 using Snellen charts were examined before Nd-YAG capsulotomy and 14 days postoperatively. 2. Contrast sensitivity (CS) was tested on a computerized system of the Contrast sensitivity 8010 type and on VCTS charts in 6 spatial frequencies, BCVA was measured on the logMAR charts with Landolt rings and influence of glare of 342.6 cd/m2 was tested using Brightness Acuity Tester (BAT). 3. BCVA (without and under glare) in patients before and after YAG capsulotomy was significantly lower compared to the control group (p < 0.001). Postoperative improvement of BCVA was markedly higher on logMAR charts (up to 6.6 standardized lines) than using Snellen charts (1 line). 4. CS (without and under glare) using both methods in patients before and after YAG capsulotomy was significantly lower compared to the control group (p < 0.05 to p < 0.001) in spite of significant improvement postoperatively (p < 0.05 to p < 0.001), first of all at intermediate and high spatial frequencies. 5. Glare had only nonsignificant influence on BCVA and CS in all groups.