Biliary obstruction following transjugular intrahepatic portosystemic shunt placement in a patient after liver transplantation: A case report

BACKGROUND

Transjugular intrahepatic portosystemic shunt (TIPS) is a method used to decrease portal hypertension. Biliary stricture is the rarest of the complications associated with this procedure with only 12 cases previously reported in the literature. None of these cases have documented the resolution of biliary stenosis induced by a stent graft. The only curative solutions reported are liver transplantation or bypassing the stenosis with an artificial biliary tract using advanced endoscopic techniques.

CASE SUMMARY

This is the first reported case of biliary obstruction secondary to TIPS placement in a transplanted liver. In our patient, a portosystemic shunt was created to treat severe veno-occlusive liver graft disease manifesting itself primarily by fluid retention. A cholestatic liver lesion and cholangitis with abscesses developed due to a stent graft-induced stricture in the dorsal segment of the right hepatic duct and the stricture diminished following percutaneous drainage. Endoscopic drainage was performed after unsuccessful removal of the percutaneous catheter resulting in a bilio-cutaneous fistula. Although the liver graft now functions well, the stricture remains refractory even after 44 mo of treatment.

CONCLUSION

Biliary strictures caused by TIPS in both transplanted and native livers seem refractory to endoscopic treatment.

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.

Benefits of Islet Transplantation as an Alternative to Pancreas Transplantation: Retrospective Study of More Than 10 Ten Years of Experience in a Single Center

BACKGROUND

Pancreas transplantation (PTx) represents the method of choice in type 1 diabetic patients with conservatively intractable hypoglycemia unawareness syndrome. In 2005, the Institute for Clinical and Experimental Medicine (IKEM) launched a program to investigate the safety potential of islet transplantation (ITx) in comparison to PTx.

AIM

This study aims to compare the results of PTx and ITx regarding severe hypoglycemia elimination, metabolic control, and complication rate.

METHODS

We analyzed the results of 30 patients undergoing ITx and 49 patients treated with PTx. All patients were C-peptide-negative and suffered from hypoglycemia unawareness syndrome. Patients in the ITx group received a mean number of 12,349 (6,387-15,331) IEQ/kg/person administered percutaneously into the portal vein under local anesthesia and radiological control. The islet number was reached by 1-3 applications, as needed. In both groups, we evaluated glycated hemoglobin, insulin dose, fasting and stimulated C-peptide, frequency of severe hypoglycemia, and complications. We used the Mann Whitney test, Wilcoxon signed-rank test, and paired t-test for analysis. We also individually assessed the ITx outcomes for each patient according to recently suggested criteria established at the EPITA meeting in Igls.

RESULTS

Most of the recipients showed a significant improvement in metabolic control one and two years after ITx, with a significant decrease in HbA1c, significant elevation of fasting and stimulated C-peptide, and a markedly significant reduction in insulin dose and the frequency of severe hypoglycemia. Seventeen percent of ITx recipients were temporarily insulin-independent. The results in the PTx group were comparable to those in the ITx group, with 73% graft survival and insulin independence in year 1, 68% 2 years and 55% 5 years after transplantation. There was a higher rate of complications related to the procedure in the PTx group. Severe hypoglycemia was eliminated in the majority of both ITx and PTx recipients.

CONCLUSION

This report proves the successful initiation of pancreatic islet transplantation in a center with a well-established PTx program. ITx has been shown to be the method of choice for hypoglycemia unawareness syndrome, and may be considered for application in clinical practice if conservative options are exhausted.

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.

[Islet transplantation as a treatment for hypoglycemia unawareness syndrome. Evaluation of the pilot program and comparison with pancreas transplantation]

Islet transplantation (ITx) started in 2005 in IKEM as a potentially safer alternative to pancreas transplantation (PTx), which so far had represented the method of choice in type-1 diabetic patients with conservatively intractable hypoglycemia unawareness syndrome. The aim of the study was to compare these two methods with regard to severe hypoglycemia elimination and to frequency of complications.Up to November 2015 a total number of 48 patients underwent ITx. The results from 22 patients with hypoglycemia unawareness were statistically analyzed. The mean number of transplanted islet equivalents was 12,096 (6,93316,705) IEQ/kg administered percutaneously in local anesthesia under radiological control to the portal vein. 44 patients underwent PTx from 1996. We evaluated glycated hemoglobin(HbA1c), insulin dose, fasting and stimulated C-peptide, frequency of severe hypoglycemia and complications. Medians (interquartile range) were analyzed using the Wilcoxon signed-rank test.One and two years after ITx, HbA1c decreased, C-peptide became significantly positive, insulin dose and frequency of severe hypoglycemia decreased and 18 % of ITx recipients were temporarily insulin-independent. Bleeding was present in 41 % of patients. One year after PTx, 73 % of patients were insulin and hypoglycemia-free, after two years 68 % of patients were insulin and hypoglycemia-free; graftectomy occurred in 20 % of recipients.Both methods led to restoration of insulin secretion and severe hypoglycemia elimination. PTx made more recipients insulin-independent at the cost of serious complications.

Primary Whipple disease of the brain: case report with long-term clinical and MRI follow-up

Whipple disease (WD) is a rare systemic disorder caused by the bacteria Tropheryma whipplei. In its classic form, it manifests with gastrointestinal problems including diarrhea, abdominal pain, and weight loss. However, various other systems can be affected, including the central nervous system (CNS). Even more rarely, the CNS is primarily affected without gastrointestinal symptoms and with a negative small bowel biopsy. The incidence of primary CNS WD is unknown. We report the case of a young female with the primary CNS form of WD. In this report, we highlight the main clinical features and diagnostic procedures that lead to the diagnosis and comment on the treatment and clinical response. We stress the importance of neuroimaging and brain biopsy. A unique feature of this case is that the patient has been followed up for 12 years. At the time of diagnosis, no neurological manifestations were detected, although a tumor-like lesion in the right temporal lobe and hypothalamic infiltration were present on magnetic resonance imaging (MRI). The first neurological manifestations developed 2 years later despite recommended antibiotic treatment, with cognitive impairment developing more than 10 years later. According to the MRI findings and clinical course, the disease was active for several years when multiple lesions on MRI appeared despite antibiotic therapy. In the discussion, we compare the present case with similar cases previously reported and we elaborate on the similarities and discrepancies in clinical features, diagnostic procedures, results, and treatment options.

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]

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.

[Long-term follow-up of the first 500 liver transplant recipients transplanted at the Institute for Clinical and Experimental Medicine in Prague]

BACKGROUND

Between April 1995 and November 2005, 500 liver transplantations were performed in 476 patients of age from 3, till 70, at the Transplantation center of the Institute of Clinical and Experimental Medicine (IKEM) in Prague. The most common indications for liver transplantation were alcoholic liver cirrhosis (23%), hepatitis C cirrhosis (17%), and cholestatic cirrhosis (PBC and PSC, 9% each). Mean MELD score of recipients at the transplantation was 15-18 for each year of transplantation. Ten-years patient survival was 79.1 +/- 2.2%, and graft survival 74.1 +/- 2.1% respectively. Best patient and graft survival was achieved among patients transplanted for autoimmune liver diseases, the worst in group of patients with alcoholic cirrhosis. Malignancies were the most common cause of death during the period of follow-up (17 patients).

METHODS AND RESULTS

Patients were followed longitudinally at the Department of hepatogastroenterology IKEM according to prospective protocol included protocol biopsies. Hypertension (in 71% of recipients), and overweight or obesity (in 56.3%), were the most prevalent medical complications among long-term survivors. Diabetes was found in 28.6%, of which 14.7% was de-nove diabetes after transplantation. Renal insufficiency (S-creatinin > 150 micromol/l) was present in 61 of 348 (17.6%) survivors. Out of these, 16 needed chronic hemodialysis, and 12 underwent kidney transplantation subsequently. Protocol biopsy at 5 years after transplantation was evaluated in a sample of 102 unselected liver transplant recipients. Normal liver was found in 4% of recipients, minor non-specific changes in 36% of them. Disease recurrence was present in all of 16 recipients transplanted for HCV cirrhosis, in one third of them graft cirrhosis was already present. Disease recurrence was found in patients transplanted for autoimmune disease frequently, PBC in 40%, PSC in 25%, and autoimmune hepatitis in 60% of recipients. Graft steatosis greater than 33% was present in 13% of recipients.

CONCLUSIONS

Liver transplantation is highly effective method of treatment of end stage liver disease. Despite frequent medical complications, and disease recurrence on histological examination almost 80% of recipients transplanted in the liver transplantation program in IKEM survived more than 10 years after procedure. The survival achieved was far above that of the European liver transplant registry.

[Islet transplantation for treatment of type-1 diabetes mellitus]

BACKGROUND

Organ pancreas transplantation represents the only method enabling long-term normalization of glucose metabolism in type-1 diabetic subjects so far. Unfortunately, surgical complications of this kind of therapy are still frequent. As a safer alternative, transplantation of isolated pancreatic islets was introduced at the Institute for Clinical and Experimental Medicine as a clinical experiment in the year 2005.

METHODS AND RESULTS

We isolated the islets from pancreases of cadaveric donors which did not fulfil criteria to perform organ pancreas transplantation. Altogether, 36 islet implantations were performed in 28 C-peptide negative subjects suffering from type-1 diabetes by August 2010. In 15 subjects (21 implantations) the main indication was extremely instable course of diabetes due to the hypoglycaemia unawareness syndrome. In 5 and 3 cases, combined islet and kidney and islet and liver transplants were performed, respectively. In addition, islet autotransplantation was performed in 5 subjects undergoing total pancreatectomy. No patient died during the study period. In all but 1 patient with primary islet afunction, islet transplantation led to a complete cure of the hypoglycemia unawareness syndrome. Out of 15 patients, 11 subjects in this group showed a significant C-peptide production (> 0.2 pmol/ml) after 1 year. The mean insulin dose after allotransplantation decreased from 37 to 14 units per day and in 3 subjects, insulin therapy could be withdrawn. Serious technical complications occurred in 6 subjects, which only in 2 cases required surgical revision and did not cause long-term sequels.

CONCLUSIONS

In comparison with organ pancreas transplantation, pancreatic islet transplantation represents a substantially safer method for restitution of endogenous insulin production. Though it eliminates serious hypoglycemic episodes in labile diabetes, complete insulin withdrawal is still often not possible. However, due to continuing progress in the laboratory techniques as well as in the transplant procedure itself, the results are steadily improving.

[Transarterial chemoembolization in hepatocellular carcinoma]

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.

[Vascular complications after pancreatic transplantation]

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]

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)]

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]

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.

[The photopic ERG response in diabetes mellitus]

The authors made photopic ERG examinations according to the international standard in 82 diabetic patients. They recorded a significant reduction of amplitudes of the b wave in a group of 38 patients who at the time of the examination did not have yet any pathological changes on the fundus. Regressive analysis did not prove after laser photocoagulation in these patients, contrary to a control group and diabetic patients with simple diabetic retinopathy, any correlation between the patients age and the extent of the retinal response. Photopic electroretinograms must be included in the electrophysiological diagnostic arsenal in diabetes.

Multi-site interventional real-time procedure demonstrations with the use of integrated services digital network connections

PURPOSE

To evaluate the effectiveness and cost of commercially available video conferencing units and standard Integrated Services Digital Network (ISDN) connections for real-time multi-site transmissions of interventional procedures.

METHODS

A network of five separate interventional radiology departments-three in the Czech Republic and one each in Austria and the USA-was established using Polyspan (Polycom in the USA) View Stations and ISDN connections. This network was used for transmissions of 16 live interventional procedures to the Sixth International Workshop on Interventional Radiology in Prague, Czech Republic in June 2000.

RESULTS

The transmissions were successful and of sufficient quality to contribute to the educational success of the workshop. The cost of the ISDN transmissions was a fraction of satellite transmission costs.

CONCLUSION

Multi-site real-time interventional procedure transmissions using video conferencing Polyspan (Polycom) View Stations and ISDN connections are a promising means of improving interventional tele-education and decreasing its cost.

[Comparison of visual function in myopia over -6.0 dpt after photorefractive keratectomy and laser in situ keratomileusis]

1. 41 myopes undergoing PRK and 31 patients undergoing LASIK for correction of spherical refractive error were examined before and 1, 3, 6 a 12 months after surgery on Schwind Multiscan with ablation zone between 5 and 7 mm. Mean preoperative spherical equivalent of refraction was -8.0 +/- 1.7 D in PRK group and -9.2 +/- 2.1 D in LASIK one. 2. Contrast sensitivity (CS) was tested on a computerized system of the Contrast sensitivity 8010 type in 6 spatial frequencies (0.74; 1.97; 3.69; 7.39; 14.77; 29.55 c/deg) and the best corrected visual acuity (BCVA) was measured on the normalized charts with Landolt rings. 3. At 12 months postoperatively, mean spherical equivalent of refraction was -0.6 +/- 1.0 D (PRK) and -1.0 +/- 0.8 D (LASIK). A refractive error within +/- 0.5 D had 31.5% (PRK) and 57.5% (LASIK) patients. Increasing of BCVA was measured in 51.5% (PRK) and 41.9% (LASIK) patients about 1 optotype to 2.5 lines. Mean CS in 6 frequencies reached 99.4; 102; 105; 109; 115 and 140% of preoperative values in PRK group and only 96; 95.8; 96.3; 95.8; 97.8 and 94.6% in LASIK one. 4. At 12 months after surgery, mean spherical equivalent, CS was better and number of patients with increased BCVA was significantly higher after PRK, than those attained with LASIK. On the other hand, a number of patients with a refractive error within +/- 0.5 D was higher and percentage of reoperations was lower in LASIK group.

Percutaneous interventions for vascular dialysis access

A prerequisite for the long-term patency of vascular access is early detection of a failing shunt, i.e., at the stage of stenosis. Fistulography performed to locate the lesion is followed by percutaneous transluminal angioplasty using a balloon catheter. The procedure takes 30-60 minutes to complete; the clinical success rate varies between 85% and 98%. A more serious condition of failled vascular access is its occlusion secondary to thrombosis. The high costs of hospitalisation and treatment of thrombosed shunts require effective yet less invasive outpatient procedures. Recent years have seen an explosion in the development of mechanical devices on the principle of mechanical dissolution, fragmentation, and aspiration of the clot. Post-procedural dialysis can be performed immediately thus reducing the need for a central venous catheter. The procedure, particularly in the treatment of native fistula occlusion, is more complicated and about twice as time consuming as treatment of stenosis. The clinical success rate is usually between 71% and 100%. The incidence of serious complications of percutaneous treatment is low.

[Analysis of the time course in electroretinography potentials]

1. For isolating of electroretinographic oscillatory potentials (Ops) a method of algebraic polynomial approximation of the low-frequency course of the electroretinogram is described. 2. Using the described method of approximation in 16 subjects, the isolated Ops displayed peak-latencies by 1-2 ms shorter than using the Fast Fourier Transform and a time window. Moreover, the amplitudes of OP1 were by 20% and of OP2 by 6% higher.

The cutting pericardiotome: another option for pericardiopleural draining in recurrent pericardial effusion. Initial experience

Large recurrent pericardial effusion can be managed by repeat pericardiocentesis or by surgery. A relatively new, catheter-based method uses a balloon catheter (percutaneous balloon pericardiotomy) for drainage from the pericardial sac to the pleural space. As an alternative, we present a newly developed device: Cutting pericardiotome.

[Visual function in myopia 2 years after photorefractive keratectomy]

1. 86 myopes undergoing photorefractive keratectomy (PRK) with refraction from -0.25 D to -12.00 D were divided into 4 groups: A: up to -2.75 D, B: -3.00 D to -5.75 D, C: -6.00 D to -8.75 D and D: -9.00 D to -12.00 D. 20 emmetropes of the same median age were evaluated as a control group. The patients were examined 2 years after PRK. 2. Best corrected visual acuity (BCVA) increased in groups A, C, D and decreased in group B compared to values one year after PRK. Both changes were only nonsignificant. 3. Contrast sensitivity (CS) was equal to values one year after PRK in group A, the same was true for groups C and D with exception of lower values in the highest spatial frequency. In group B, CS decreased significantly compared to values one year after PRK. 4. In groups A, B a C number of patients without rest correction increased, regression was seen only in group B. 5. BCVA changed only nonsignificantly under glare of 41.1 cd/m2, 342.6 cd/m2 and 1360.4 cd/m2 in 97% of patients.

[The scotopic electroretinogram and age]

1. Electroretinographic examination according to recommendations of the International Society for Clinical Electrophysiology of Vision (ISCEV) was implemented in 115 healthy subjects of different age groups. 2. No significant difference was recorded in the results of men and women. 3. The amplitudes of all investigated retinal responses decline in a linear fashion with age and their peak latencies are prolonged. The mentioned changes are statistically significant even if changes of 0.5 to 0.8% per year are involved.

[Hereditary occurrence of deep cavities in the optic nerve associated with Best's disease]

The authors present a pedigree where in three generations in male members deep excavations of the optic discs along with Best's disease of the centres in a variable form were recorded. The heredity is autosomal dominant. Retinal changes conditioned by defects of the pigmented epithelium reduce vision to a maximum of 6/60. The anomaly is associated with a pathological EOG record and normal ERG response. The observation is a contribution to discussions in the literature about the hereditary character of excavations of the optic nerve.

[Changes in visual function in myopia 12 months after photorefractive keratectomy]

1. 110 myopes undergoing photorefractive keratectomy (PRK) with refraction from -0.25 D to -12.0 D were divided into 4 groups: A: upto -2.75 D, B: -3.0 D to -5.75 D, C: -6.0 D to -8.75 D and D: -9.0 D to -12.0 D. BCVA using the computerized method with Landolt rings and CS using an adjustment method with ascendant and descendent approach to threshold contrast adaptation on a computerized system of the Contrast sensitivity 8010 type were examined in patients before and 1 year after PRK. 20 emmetropes of the same median age were evaluated as a control group. 2. Preoperative BCVA and CS in myopes of all four groups was significantly lower (p < 0.05 az p < 0.001), compared to controls. Decrease of functions was proportional to refraction. 3. With increasing refraction less patients were within +/- 0.5 D and +/- 1.0 after surgery. 4. Twelve months after PRK, BCVA in the group A reached the level of controls, CS in the same time interval was equal to control even in groups A and B. 5. According to results of our study, PRK is a suitable method for myopia upto -6.0 D.

[Electrophysiology in hypovitaminosis A]

Electroretinographic examinations performed according to the international standard were used in two patients with alimentary hypovitaminosis A. In one instance a mentally caused long-term deficiency of dietary vitamin A intake was involved, in the second instance a fistula from the proximal jejunum into the transverse colon. In both instances night blindness was reported. The initial vitamin A values were 1.0 and 0.6 micromol/l resp. and after substitution therapy they rose to 2 micromol/l. While the rod and maximal ERG responses improved gradually, the oscillation potentials remained pathological as regards amplitudes and latencies. We consider them therefore a sensitive indicator of the electric sensitivity of the retina also in other cases of confirmed or suspected vitamin A deficiency. The existence and orientation of our metabolic and gerontological clinic provides adequate opportunities for these investigations.

Mechanical thrombectomy of massive pulmonary embolism using an Arrow-Trerotola percutaneous thrombolytic device

Mechanical thrombectomy of a large central thrombus in massive pulmonary embolism is a new option for the treatment of this serious condition. The special mechanical devices designed to fragmentize a blood clot include the Arrow-Trerotola percutaneous thrombolytic device (PTD), the use of which in the pulmonary arteries has not yet been reported. The case of massive embolism into the left pulmonary artery with subsequent collapse is to demonstrate the immediately clinically successful treatment using the PTD. Our initial experience with the PTD shows that its use is a safe and quick procedure.

[Changes in visual functions in myopia 6 months after photorefractive keratectomy]

I. 100 myopes (-0.25-(8.75) D) divided into 3 groups (I: < -3.0 D, II: -3.0-(-5.75) D, III: -6.0-(-8.75) D) were examined before and 1, 3, 6 months after photorefractive keratectomy (PRK). As a control group 20 emmetropes were examined. Best corrected visual acuity (BCVA) was tested using logMAR charts. Contrast sensitivity (CS) was measured using a computerized system. II. Preoperative BCVA in myopes of all three groups was significantly lower (p < 0.001) compared to the control group. A significant reduction of BCVA (p < 0.05 resp. p < 0.001) in all groups at all terms after PRK was noted. III. Significantly lower values of CS (p < 0.001) were found in myopes of all groups before PRK in comparison to the control group. One and 3 months after PRK only nonsignificant changes of the mean values of contrast sensitivity (MCK) were noted. After 6 months a significant improvement of MCK (p < 0.05) in myopes of I. and II. groups was observed.

Visual functions in aphakia after secondary intraocular lens implantation

21 aphakic eyes of 21 patients corrected by glasses (A-G) were examined 1 and 6 months before and after secondary intraocular lens implantation (SILI). Visual acuity (VA) was tested using Snellen chart and computerized method with Landolt rings (CL). Contrast sensitivity (CS) was measured using computerized Contrast sensitivity system 8010 in spatial frequencies from 0.74 to 29.55 c/deg. Preoperative best corrected VA (BCVA) in A-G eyes was significantly lower in comparison with control group of the same age only using computerized method with Landolt rings. A reduction of BCVA by both methods at 1 month and its return to original values after 6 months were noted. Significantly lower values of CS were found in A-G patients before SILI compared to the control group of the same median age in spatial frequencies from 3.69 to 29.55 c/deg. After 1 and 6 months the values stayed on the preoperative level, except the frequency 29.55 c/deg, which increased significantly (p < 0.01) 6 months after SILI.

[Oscillatory potentials in human electroretinography during adaptation to light and dark]

In 20 healthy subjects no changes of the peak-latencies of the four wavelets of electroretinographic oscillatory potentials (OP) was found in the course of dark- and light-adaptation. On the other hand, their peak-to-peak amplitudes and dominant frequencies diminish significantly with rising levels of light adaptation. No single OP wavelet was affected by these changes selectively. The OP peak latencies are well suited for clinical diagnostic testing owing to their stability and low variability. On the other hand, because of the great interindividual variability of the peak-to-peak amplitude values of the OP a better clinical tool appears to be a sum of their amplitudes.

Visual functions after photorefractive keratectomy

1. 45 myopes (-3.0 to -6.0 D) were examined before and 1 and 6 months after photorefractive keratectomy (PRK). Visual acuity (VA) was tested using Snellen and logMAR charts. Contrast sensitivity (CS) was measured using a computerized system. 2. Preoperative best corrected VA (BCVA) in myopes was significantly lower in comparison with a control group using logMAR charts only. A reduction of BCVA by both methods at 1. month and its return after 6 months nearly to original values was noted. 3. Significantly lower values of CS were found in patients before PRK compared to the control group. After 1 and 6 months stayed the values on preoperative level.

[Visual function in hypophyseal tumors]

Visual acuity measured using the Snellen method in 29 patients with hypophyseal tumors amounts to normal or nearly normal values (6/9-6/6), with mean value of 0.75. Measuring of visual acuity with the more accurate "log MAR" optotype tables yields acuity values which decline with the severity of the disease from 1.04 to 0.87 with a mean value of 0.97. Not withstanding, in all of these patients markedly lowered contrast sensitivity values were found in all of the frequencies tested (1.15-29.25 c/deg). The use of the visual acuity determinations only is insufficient for early detection of functional visual disturbances in compressions of the visual pathway.

[ERG findings in structured conditions (PERG) in the diagnosis of glaucoma]

In 34 patients admitted to the clinical examination on the basis of the finding of the higher intraocular pressure stated in the private praxis the PERG examination has been performed. After the clinical examination (intraocular pressure, Humphrey perimeter, gonioskopy, C/D ratio) two groups of patients have been classified: 1. Glaucoma patients (21 persons) 2. Patients without glaucoma (13 persons). In the first group a significant lowering of the b65 amplitude of the PERG has been found. Thus the diagnostic value of the PERG in early glaucoma has been confirmed.

[Congenital stationary night blindness]

The clinical and electrophysiological data in 48 cases of congenital stationary night blindness (CSNB) are analysed. The existence of the complete (with only the cone part of the dark adaptation curve) and incomplete (some rod activity also present) form of this anomaly has been confirmed. The Schubert-Bornschein's type of ERG responses corresponds to the complete CSNB. After 12 years of observation period in some patients the diminution of both the a and b potential of the ERG curves but not the extinction of the ERG potentials has been found. PERG curves and PVEP responses in CSNB are normal. Two pedigrees of CSNB are presented. The first reflects the autosomal dominant mode of heredity in 4 generations, in the second pedigree (5 generations) it is not possible to estimate the mode of heredity.

[Cataracts and contrast]

The value of visual acuity in patients with incipient cataract, as measured using the conventional Snellen charts amounts to normal or near normal values (6/9-6/6). Nevertheless, their contrast sensitivity determined using the Ginsburg charts or optotypes with lowered contrasts is markedly depressed. The measurement of the visual acuity alone is insufficient diagnostic purposes in these patients.