Corrections of HPGe detector efficiency curve due to true coincidence summing by program EFFTRAN and by Monte Carlo simulations.

Standard reference sources, used for efficiency curve calibration of detector, often contain radionuclides with complex decay schemes (such as 60Co, 88Y, 152Eu …), introducing a potential problem in gamma-ray spectrometry, due to the appearance of coincidence summing of detected photons, in particular at a low source-detector distance. In this paper, a set of Monte Carlo simulations of an identical experimental setup were performed in order to obtain the efficiency curve of coaxial p-type HPGe detector for energy region (0-2) MeV, with the effect of true coincidence summing and without it. Obtained efficiency curves are compared with the experimental curve after applied EFFTRAN corrections. Fairly well agreement (between simulated and experimental curves with EFFTRAN corrections (with a relative deviation of 10%) proved the reliability of EFFTRAN corrections, as well as the possibility of Monte Carlo simulations for efficiency curve determination.

[Analysis of programmed pacing rate levels in patients with the carotid sinus hypersensitivity syndrome and implanted Clarity pacemakers]. / Analiza nivoa programisane frekvencije impulsa pejsmejkera kod bolesnika sa sindromom preosetljivosti karotidnog sinusa u ugradjenim pejsmejkerom "Klariti".

New Clarity DDDR pacemaker system (Vitatron Medical B.V.) Clarity DDDR, provides an option for recognizing sudden rate drop and responding by intervention pacing until it detects the recovering. In patients in whom syncopal episodes are mainly caused by occasional drops in heart rate, Sudden Rate Drop Intervention feature intends to provide high rate intervention pacing. We have implanted 10 of these devices in our Centre, 2 of which in patients with hypersensitive carotid sinus syndrome. In patients with carotid sinus syndrome it is possible to provoke this situation by sinus caroticus massage. In both patients, we activated Sudden Rate Drop Intervention on DDD mode pacing and used protocol for testing the necessary level of sudden Rate Drop Intervention Rate. Both patients gave their informed consent to be submitted to this testing. Pacemaker software assumes rate intervention level of 110 bpm. We tested our patients for rate levels of 90 and 110 bpm. Massaging the carotid sinus during 5 seconds, we provoked sudden Rate Drop Intervention 10 times, in each patient, 5 times at intervention rate of 90 and 5 times at 110 bpm. Patients were unaware of the programmed intervention rate and were merely expected to report any different sensations experienced during the testing. In all 20 tests, pacemaker responded to sudden rate drop elicited by carotid sinus massage (100%), that was verified by selected event recordings. After the massage, no patient experienced any sensation at sudden rate drop intervention rate level of 90 bpm in a total od 10 tests (100%), while 8 of 10 messages at 110 bpm intervention rate provoked palpitations (80%). We concluded that lowering of Sudden Rate Drop Intervention Rate Level from 110 BPM to 90 BPM did not affect the reliability of system reaction, but changes of patient's awareness of heart beats. As a final conclusion, it should be said that basic prerogatives of a pacing system are: safety and efficacy with minimal energy consumption, and in this case, quality of life option that a patient practically does not feel intervention when it occurs, are all met.

Sudden rate drop intervention rate level in patients with new 'clarity' pacemakers and carotid sinus syndrome.

BACKGROUND: In patients in whom syncopal episodes are mainly caused by occasional drops in heart rate, Sudden Rate Drop intervention feature intends to provide high rate intervention pacing. New Vitatron Medical B.V. pacemaker system Clarity DDDR, provides AN option FOR recognizing Sudden Rate Drop and responding by intervention pacing until it detects the recovering. MATERIAL AND METHODS: In patients with carotid sinus syndrome it is possible to provoke this situation BY sinus carotidus massage. We have implanted 10 of these devices in our center, 2 of which in patients with hypersensitive carotid sinus syndrome. In both patients, we activated sudden rate drop intervention on DDD mode pacing and applied protocol for testing the necessary level of Sudden Rate Drop Intervention Rate. Both patients gave their informed consent to be submitted to this testing. Pacemaker software assumes rate intervention level of 110 bpm. We tested our patients for rate levels of 90 and 110 bpm. Massaging the carotid sinus during 5 seconds, we provoked Sudden Rate Drop Intervention 10 times, in each patient, 5 times at intervention rate of 90 and 5 times at 110 bpm. Patients were unaware of the programmed intervention rate and were merely expected to report any different sensations experienced during the testing. RESULTS: In all 20 tests, pacemaker responded to sudden rate drop elicited by carotid sinus massage (100%), which was verified by selected event recordings. After the massage, neither of the patients registered any sensations at sudden rate drop intervention rate level of 90 bpm in a total od 10 tests (100%), while 8 out of 10 massages at 110 bpm intervention rate provoked palpitations (80%). On the grounds of this testing, we concluded that lowering of Sudden Rate Drop Intervention Rate Level from 110 BPM to 90 BPM does not affect the reliability of system reaction, but changes patient's awareness of heart beats. CONCLUSION: As a final conclusion, it should be said that basic prerogatives of a pacing system: safety and efficacy with minimal energy consumption, and in this case, quality of life option that a patients practically does not feel intervention when it occurs, are all met.

The loss of circadian heart rate variations in patients undergoing mitral valve replacement and Corridor procedure--comparison to heart transplant patients.

We have presently demonstrated that when added to mitral valve replacement (MVR) the corridor procedure is 75% efficient in restoring and maintaining sinus rhythm in patients with chronic atrial fibrillation (AF), caused by rheumatic mitral valve disease, (follow up 13.9months). In the same patient population, we observed that the typical day-night cycle heart rate (HR) variations were lost and our present study concentrates on this subject. Heart rate variability analysis based on 24-h Holter ECG recording (StrataScan 563 DelMar Avionics) or hospital discharge (12th-14th postoperative days) was performed in 3 patient groups: Group I: Patients with a Corridor procedure added to MVR (12pts, m/f 10/2, mean age 47.3+/-7.5yr); Group II (control): with patients MVR performed through the left atrial approach, without additional antiarrhythmic procedures (10pts, m/f 3/7 mean age 51.5+/-6.7yr), and Group III: heart transplant recipients (5pts, mean age 46.4+/-11.22yr). We analyzed the hourly heart rate over 24-h period divided into three 8-h segments (07-14h; 15-22h and 23-06h). Statistical comparison of mean hourly heart rate values was made between the three time periods of Holter monitoring. The Corridor procedure performed with mitral valve replacement resulted in conversion of sinus rhythm in 75% of patients (Group I), but postoperative heart rate variability analyses based on Holter monitoring disclosed that the mean heart rate was not statistically significantly difficult between the three 8-h segments of the day-night (P>0.05). The same results were found in the group of patients after heart transplant (P>0.05). The same results were found in the group of patients after heart transplant (P>0.05). In the second group (classical MVR), statistically significant differences in mean HR variation existed between the three 8-h intervals (P<0.05), and although atrial fibrillation occurred postoperatively physiologic circadian heart rate variations were preserved. With the Corridor procedure, both atria were surgically and electrically isolated and chronotropic function of the ventricles was restored by creating a small strip of atrial tissue with isolated sinus node and atrio-ventricular node, connected to the ventricles. This technique produced heart denervation nervous system influence, producing the loss of circadian HR variations, similar to the transplanted heart.

Permanent endocardial pacing by cephalic vein access in new-borns and infants--surgical techniques.

Most centers worldwide use permanent endovenous cardiac electrostimulation in children requiring pacing whose body mass is over 10kg. The normal implantation route is via a subclavian vein puncture. In our Center, we have implanted permanent endovenous pacing systems for complete AV block in nine children with a mean body mass 7.4kg (range 2.45-10kg). The endovenous lead was placed using cephalic vein cutdown procedure. To allow 'sliding' during the child's growth, the lead was secured by absorbable sutures.

[Metabolic parameters in the evaluation of frequency-adaptive sensors in pacemakers]. / Metabolicki parametri u proceni senzora frekventno-adaptivnih pejsmejkera.

A comparison was made between metabolic parameters during exercise in patients with implanted dual sensor VVIR pacemakers. We analyzed two groups of patients with implanted dual sensor responsive pacemakers. The first group was composed of 14 patients (mean age 37.7 years) who had implanted Topaz pacemakers. The second group of 9 patients had a Legend Plus (mean age 44.7 years). A control group consisted of 54 healthy individuals (mean age 40.4 years). Testing was performed on treadmill, using a stepwise staircase loading CAEP protocol. Directly measured and mathematically calculated parameters used in assessment of metabolic impact of pacemaker function were: minute ventilation (MV), MV/body surface, MV/body mass unit, oxygen consumption, oxygen consumption/body surface, oxygen consumption/heart rate (oxygen pulse), oxygen consumption/body mass unit, carbon dioxide production, respiratory index. The majority of the observed parameters revealed no statistically significant difference between the control group and the patients with dual sensor or single sensor controlled rate response. However, oxygen pulse showed a statistically significant difference when comparing the group with single sensor controlled rate response with dual sensor controlled rate response and control group (p < 0.05). Other parameters indicating an advantage of dual sensor controlled rate were the time period of reaching anaerobic threshold (respiratory index) and exercise duration. They both displayed a statistically significant difference between dual sensor controlled rate response and single sensor rate response (p < 0.05) with no significant difference compared to control group (p > 0.05).

Absorbable suture technique: solution to the growth problem in pediatric pacing with endocardial leads.

Endocardial pacing system implantation has been performed in 15 children of mean age 37 months (ranging from 1 day to 89 months). Endocardial lead fixation was performed by means of slowly resorbable suture (Dexon) to allow spontaneous lead migration as the child grows. During a mean follow-up period of 61 months (range 17-108 months), none of the patients needed reintervention for correcting the lead length to allow growth.

Corridor procedure--surgical option for treatment of chronic atrial fibrillation in patients undergoing mitral valve replacement.

The aim of this study was to determine the effectiveness of the 'corridor' procedure when added to mitral valve replacement in restoring and maintaining sinus rhythm in patients with chronic atrial fibrillation resulting from rheumatic mitral valve disease. Twenty-two patients with rheumatic mitral valve disease and chronic atrial fibrillation with fast, irregular ventricular response were divided into two groups. In the first group (n = 12), mitral valve replacement was combined with sinus node-AV node isolation ('corridor'): in the second, control group (n = 10), mitral valve replacement was performed through the left atriotomy. The effectiveness of the 'corridor' procedure on heart rhythm was analysed by: (i) 24-h Holter monitoring performed before and during 72 h after surgery, at hospital discharge, and 2 months later; and (ii) postoperative electrophysiological studies using temporary epicardial wires on each isolated atrial compartment. Immediately after surgery and in the following 2 months, heart rate variability analysis showed significantly lower hourly ventricular rates and rate variations in the 'corridor' group compared with those of the control group (P < 0.01). A significant difference was also found when comparing postoperative to preoperative findings in the corridor group (P < 0.05). In the control group, however, no significant differences (P > 0.05) were found concerning pre- and postoperative ventricular rate variations. At hospital discharge, nine of 12 patients with 'corridor' procedure were in sinus rhythm. Control patients remained in atrial fibrillation with irregular ventricular rate. The 'corridor' procedure, when added to mitral valve replacement, prolonged surgery, but led to restoration and long-term maintenance of sinus rhythm in 75% of patients with chronic atrial fibrillation and rheumatic mitral valve disease.

[Aneurysms of the carotid arteries]. / Aneurizme karotidnih arterija.

The aim of the paper is the presentation of the treatment of aneurysms of the extracranial carotid artery and review of literature. Aneurysms of extracranial carotid arteries (common carotid artery, external carotid artery and cervical part of the internal carotid artery) are very rate [1, 2]. In 1979 McCollum from the Baylor University (Houston, Texas) reported 37 cases over a 21-year period [3]. Moreau from France reported 38 cases over a 24-year period [4]. Mayo clinic experience includes 25 cases in the 40-year period [5]. According to Schechter 835 extracranial carotid artery aneurysms were reported in literature until 1977. These and the other aneurysms of the extracranial carotid artery can be partially or completely thrombosed, can cause distal embolization, or compression of adjacent structures, and can be ruptured [4, 9]. Therefore, the mortality rate in non operated patients with carotid artery aneurysm is 70% [10]. Over the period from January 1, 1985 to December 31, 1996 at the Centre of Vascular Surgery within the Institute of Cardiovascular Diseases of the Serbian Clinical Centre in Belgrade, 12 patients with 13 extracranial carotid artery aneurysms were treated. Nine of them (75%) were males and 3 (25%) females, average age 58.22 (21-82) years. There were two traumatic (gunshot wounds) and one anastomotic (after carotid subclavian bypass with PTFE graft) pseudoaneurysms, and 10 true atherosclerotic aneurysm. Three (23%) aneurysms were on the common and 9 (77%) on the cervical part of the internal carotid artery. Two (15%) aneurysms were in the form of asymptomatic pulsatile neck mass, 7 (54%) with CVI or TIA, three (23%) with compression of the cranial nerves and one (8%) was ruptured. Twelve (92%) patients were treated surgically, while one asymptomatic aneurysm in a 82-year old female patient was not operated due to high risk. The intraoperative findings revealed one complete and 11 partial thromboses of the aneurysmal sac. In 3 patients with fusiform aneurysms, thrombectomy and aneurysmorrhaphy were performed. One traumatic pseudoaneurysm was treated with aneurysmectomy and lateral suture of the artery. In 3 patients aneurysmectomy and end to end anastomosis were done, while in three aneurysmectomy and saphenous vein graft interposition. In case of ruptured aneurysm of the internal carotid artery aneurysmetomy and arterial ligature were carried out, while in case of anastomotic pseudoaneurysm after carotid subclavian bypass, aneurysmectomy and new carotid subclavian bypass with PTFE graft, were performed. During the study no intrahospital mortality was recorded. One patient died 5 years after the operation due to myocardial infarction. The mean follow-up period was 4 years and 2 months (6 months to 11 years). The early and late potency rates were 100%. Two (17%) CVI and two transient cranial nerve paresies were noticed immediately after the operation. In literature male/female ration in patients with extracranial carotid artery aneurysms is 2:1 [2, 4, 7], but in our study it was 5:1. One (10%) of our patients had a bilateral carotid artery aneurysm. According to literature data the incidence of bilateral localization of extracranial carotid artery aneurysms with atherosclerotic origin is 21% [1]. Of 12 surgically treated aneurysms in our study, 9 were of atherosclerotic origin, two were traumatic and one anastomotic pseudoaneurysms. Today, most of true extracranial carotid artery aneurysms are of atherosclerotic origin [7, 20-25]. However, true extracranial carotid artery aneurysms can be developed due to: infection of the arterial wall (mycotic forms) [26-37]; nonspecific [23] or irradiation arteritis [38], fibromuscular dysplasia [4, 8, 15, 16, 39]. The most frequent types of false extracranial carotid artery aneurysms are traumatic pseudoaneurysms [32, 50-54] and anastomotic pseudoaneurysms [53, 59, 60]. There are also dissecting extracranial carotid artery aneurysms developed after isolated spontaneous d

Popliteal artery war injuries.

The early postoperative results of 44 surgically treated popliteal arterial injuries from the Yugoslav civil war are reported. Of these patients, 41 (93%) were males and three (7%) were females, average age was 28 (range 6-45) years. Twenty patients (45%) had gunshot wounds and 24 (55%) explosive wounds. Twelve (28%) suffered isolated vascular damage, while 32 (72%) suffered concomitant bone fractures. Isolated arterial lesions were found in 24 (55%) cases, and concomitant arterial and venous lesions in 20 (45%). Twenty-four (55%) had primary reconstructions after haemostasis in the initial war hospital, and 20 (45%) secondary reconstructions after inadequate primary reconstruction in a regional war hospital. Artery procedures included 19 reverse saphenous vein graft interpositions, 10 reverse saphenous vein bypasses, 12 'in situ' saphenous vein bypasses and five lateral subcutaneous saphenous vein bypasses. The early graft patency rate was 100%, and limb salvage 72%. Major amputation was performed in 28%. Concomitant bone fractures, secondary reconstructions, secondary haemorrhage from an infected graft, and explosion wounds significantly increased the amputation rate (P < 0.01). Eleven amputations were performed after an anatomic, and only one after an extra-anatomic reconstruction (P < 0.01). The authors recommend an in situ or lateral subcutaneous reconstruction in cases of complicated popliteal artery injuries, such as concomitant bone fractures accompanied by massive soft tissue damage, and this type of reconstruction should also be used if infection is present or the procedure is delayed.

[Factors determining late patency of aortobifemoral bypass graft]. / Cinoici koji odredjuju dugotrajniju protocnost aorto-bifemoralnog bajpasa.

INTRODUCTION: Most of the patients with aortoiliac occlusive diseases have a multilevel localization of atherosclerotic diseases. In patients with aortoiliac occlusive diseases, the femoro-popliteal segment is involved in 28 to 66% of cases. These patients are usually old persons with many risk factors. Therefore, simultaneous proximal and distal reconstruction is often associated with a higher morbidity and mortality rates. In contrast, can proximal reconstruction help only patients with multilevel occlusive diseases? The aim of this paper is: definition of factors determining late patency rate of aortobifemoral bypass graft in patients with multilevel occlusive diseases; definition of factors determining clinical effects after aortobifemoral bypass procedures. MATERIAL AND METHODS: This prospective study included 283 aortobifemoral reconstructions due to aortoiliac occlusive diseases operated between January 1st, 1984 and December 31st, 1992 at the Institute of Cardiovascular Diseases of the Serbian Clinical Centre in Belgrade. Bifurcated polytetrafluorethylene (PTFE) grafts were used in 136 patients, and standard nonimpregnated knitted Dacron grafts in 147 paetients. There were 25 (8.8%) female and 258 (91.2%) male patients, average age 56.88 years. Ninety one (32.2%) patients had claudication discomfort (Fonten stadium II), 91 (32.2%) disabling claudication discomfort (Fonten stadium IIb), 45 (15.9%) rest pain (Fonten stadium III), and 56 (19.8%) gangrene (Fonten stadium IV). In 45 (15.9%) patients previous vascular procedures were performed. Prior to operation Doppler ultrasonography and translumbar aortography were done. Isolated aortoiliac occlusive diseases with intact femoro-popliteal segment (Type I) were found in 83 (29.3%) patients; combined aorto-iliac and diseases of superficial femoral artery (Type II) in 170 (60%) patients; and combined aorto-iliac and femoro-popliteal diseases (Type III) in 30 (10.7%) individuals. Transperitoneal approach to abdominal aorta and standard inguinal approach to femoral arteries, were used. In 154 (54.4%) patients proximal anastomosis had an end to side (TL), while in 129 (45.6%) end to end (TT) form. In 152 (26.88%) patients distal anastomosis was found on the common femoral artery (AFC), while in 414 (73.2%) on the deep femoral artery (APF). In 7 patients the aorto-femoro-popliteal "jumping" bypass was performed, and in 29 subjects the simultaneous sequential femoro-popliteal bypass graft (Figures 1, 2, 3, 4a and 4b). The patients were followed-up over a period from one, six and twelve months after reconstruction, and later once a year, using physical examination and Doppler ultrasonography. In patients with suspected graft occlusion, anastomotic stenosis, pseudoaneurysms, progression of distal diseases, Duplex ultrasonography and angiography were also used, and leukoscintigraphy in patients with suspected graft infection. Statistical analysis was performed by Long Rank and Student's t-test. RESULTS: Inhospital mortality rate was 11 (7%). Simultaneous distal reconstructions significantly increased the mortality rate (p< 0.01). The follow-up period was from 2 months to 9.5 years (mean 3.6 years). Configuration of proximal anastomosis showed no significant influence on graft patency (p>0.05) (Graphs 1, 2, 3). Location of distal anastomosis at the deep femoral artery contributed to statistically significant increase in graft patency (p < 0.01) (Graphs 4, 5, 6). Simultaneous distal bypass showed statistically significant increase in graft patency (p < 0.01), but also significant increase in inhopsital mortality rate (p < 0.01) (Graphs 7, 8, 9). The type of occlusive diseases had no statistically significant influence on graft patency (p > 0.05) (Graphs 10, 11, 12). Six (2.1%) early unilateral limb occlusions were observed. The reasons for early graft occlusions were: stenosis of distal anastomosis in 3 patients and pure run off in 3 subjects. In 5 patients urgent reoperations (limb thrombectomy and profundoplasty or femoro-popliteal bypass graft above the knee) were performed with complete recovery of patients. However, in one patient an above the knee amputation had to be done. During the follow-up period 14 (5.2%) late graft occlusions were recorded: 11 unilateral limb and 3 bilateral graft occlusions. The reasons for late graft occlusion were: distal progression of atherosclerotic diseases, distal anastomotic stenosis, proximal progression of atherosclerotic diseases and anastomotic neointimal hyperplasy. All patients with late graft occlusion underwent successful redo-operations. Next late redo-procedures had to be done: three new aorto-bifemoral bypass grafts (patients with bilateral occlusion), two limb thrombectomies, 6 limb thrombectomies with profundoplasty and 3 femoro-femoral "cross-over" bypass grafts. Configuration of proximal anastomosis and type of occlusive disease showed no statistically significant influence on the number of early and late graft occlusions (p > 0.05). Location of distal anastomosis at the deep femoral artery and simultaneous distal bypass, statistically significantly decreased the number of early and late graft occlusions (p < 0.05). "Small aorta syndrome" statistically significantly increased the number of late graft occlusions. Eleven distal anastomotic pseudoaneurysms were noted. In 8 patients pseudoaneurysms were infected and in 3 noninfected. In all patients new redo-operations were carried out. Graft infection was recorded in 5 (1.7%) patients. One (0.3%) secondary aortoduodenal fistula was found. During the follow-up period new disabling claudication discomforts were found in 46 patients. The causes were distal anastomotic stenosis in 30 patients and progression of distal arterial diseases in 16 subjects. Of the total number of 30 patients with distal anastomotic stenosis 14 were reoperated (profundoplasty) and 16 patients refused a new operation. Also, 16 patients with progression of distal atherosclerotic diseases were reoperated. The operation was a kind of femoropopliteal or crural bypass grafts. During the follow-up period 97 patients were asymptomatic, 128 showed significant improvement, 29 had disabling claudications, and 111 had amputations. Distal anastomosis at the deep femoral artery and patent superficial femoral artery, statistically significantly influenced the clinical course after operation (p 0.01), while configuration of proximal anastomosis and simultaneous distal bypass had no significant effects (p < 0.05). CONCLUSIONS: (1) Only location of distal anastomosis has a statistically significant influence on the patency of aorto-bifemoral bypass graft. (2) The location of distal anastomosis and type of occlusive disease have a statistically significant influence on the clinical effect of the operation. (3) The simultaneous distal bypass had no influence on the late patency of aortobifemoral bypass graft and on the number of asymptomatic patients. Also, it increased inhospital mortality rate.

[Surgery of abdominal aorta with horseshoe kidney]. / Hirurski zahvati na aorti abdominalis kod bolesnika s potkovicastim bubregom.

Seventy one surgical procedures on abdominal aorta in patients with horseshoe kidney have been reported in literature until 1980. Bergan reviewed 30 operations of abdominal aortic aneurysms (AAA) in these patients until 1974. Of them 3 AAA were ruptured. Gutowitz noticed 57 surgically treated AAA in patients with horseshoe kidney until 1984. Over the period from 1991 to 1996 thirty nine new cases were reported , including 2 ruptured AAA. The surgery of the abdominal aorta in patients with horseshoe kidney is associated with the following major problems: -reservation of anomalous (aberrant) renal arteries; reservation of the kidney excretory system; approach to the abdominal aorta (especially in patients with AAA) and graft placement The aim of the paper is the presentation of 5 new patients operated for abdominal aorta with horseshoe kidney. Over the last 12 years (January 1, 1984 to December 31, 1996) at the Centre of Vascular Surgery of the Institute of Cardiovascular Diseases of the Clinical Centre of Serbia, 5 patients with horseshoe kidney underwent surgery of the abdominal aorta. There were 4 male and one female patients whose average age was 57.8 years (50-70). Patient 1. A 50-year-old male patient was admitted to the hospital for disabling claudication discomforts (Fontan stadium IlI) and with significantly decreased Ankle-Brachial indexes (ABI). The translumbal aortography showed aorto-iliac occlusive disease and horseshoe kidney with two normal and one anomalous renal artery originating from infrarenal aorta (Crawford type II). Intravenous pyelography and retrograde urography showed two separated ureters. The aorto-bifemoral (AFF) bypass with Dacron graft was done with end-to-end (TT) proximal anastomosis just under the anomalous renal artery. The graft was placed behind the isthmus. During a 12-year follow-up renal failure, renovascular hypertension and graft occlusion were not observed. Patient 2. A 53-year-old male patient was admitted to the hospital for symptomatic AAA. Two years before admission the patient underwent coronary artery bypass grafting. The Duplex scan ultrasonography and translumbal aortography showed an infrarenal AAA, aneurysm of the right iliac artery and horseshoe kidney with two normal and one anomalous renal artery originating from the left iliac artery (Crawford type III). Intravenous pyelography and retrograde urography showed two separated ureters. After partial aneurysmectomy, the flow was restaured using bifurcated Dacron graft placed behind the isthmus. The right limb of the bifurcated graft was anastomosed with the common femoral artery and the left limb with left iliac artery just above the origin of the anomalous renal artery. The first day after operation thrombosis of the left common femoral artery with leg ischaemia was observed. (That artery was cannulated for ECC during coronary artery bypass grafting 2 years ago). The revascularisation of the left leg was done with femoro-femoral cross over bypass. During a 11-year follow-up period, the graft was patent and renal failure or revascular hypertension were not observed. Patient 3. A 66-year-old male patient was admitted to the hospital for rest pain (Fontan stadium III) and significantly decreased ABI. The patient had diabetes mellitus and myocardial infarction two months before admission. Translumbar aortography showed an aorto-iliac occlusive disease associated with horseshoe kidney with 5 anomalous renal arteries. (Crawford type III). Due to high risk, the axillo-bifemoral (AxFF) extra-anatomic bypass graft was performed. Five years after the operation the patient died due to new myocardial infarction. During the follow-up period the graft was patent and there were no signs of renal failure and renovascular hypertension. Patient 4. A 50-year old male patient was admitted to the hospital for high asymptomatic AAA. The diagnosis was established by Duplex scan and translumbal aortography. The large infrarenal AAA (transverse diameter 7 cm) associated with horseshoe kidney with two normal renal arteries (Crawford type I) were found. Intravenous pyelography and retrograde urogrpahy showed two separated ureters. After partial aneurysmectomy the tubular Dacron graft was placed behind the isthmus. During a 15-month follow-up the graft was patent and there were no signs of renal failure and renovascular hypertension. Patient 5. A 70-year-old female patient was admitted to the hospital for large asymptomatic AAA. The Duplex ultrasonography, CT scan, NMR and translumbal aortography showed an infrarenal AAA, aneurysms of the both common iliac arteries, aneurysm of the left hypergastric artery and horseshoe kidney with two normal and two anomalous renal arteries. One of the anomalous renal arteries originated from AAA, and the other from the left common iliac artery (Crawford type II). Intravenous pyelography and retrograde urography showed two separated ureters. After partial aneurysmectomy the flow was restaured using bifurcated Dacron graft placed behind the isthmus. The right limb of the graft was anastomosed (TT) with bifurcation of the common iliac artery and the left limb with the distal part of the common iliac artery (end-to-side) just above the origin of the second anomalous renal artery. The first anomalous renal artery that originated from AAA was removed from the aneurysm wall and anastomosed with graft using Carrel patch technique. During a 9-month follow-up the graft was patent and there were no signs of renovascular hypertension and renal failure. The horseshoe kidney is a rare anomaly of the urinary system. The incidence of this anomaly is from 1:1600 to 1:400 In 95% of cases the kidneys are connected with the lower poles, while in 5% with the upper poles In most cases, the isthmus structure is parenchimatous structure, and rarely it consists of the connective tissue. Usually the isthmus is located in front of the abdominal aorta and inferior vena cava, and very rarely behind them In two thirds of patients anomalous vascularization is present There are two classifications of anomalous vascularization: Papin's and Crawford's. According to Papin's classification, based on the number of renal arteries, there are three types of horseshoe kidney vascularization: Papin I (20%): There are two normal renal arteries only. (One of our 5 patients); Papin II (66%): There are 3-5 renal arteries. (Four of our 5 patients); Papin III (14%): There are more than 5 renal arteries. The Crawford's classification based on the origin of renal arteries, is of greater surgical importance than Papin's. According to it there are also three types of vascularization: Crawford I: There are two renal arteries with normal origin. (One of our 5 patients); Crawford II: Besides two normal, there are 1-3 anomalous renal arteries originating from the infrarenal aorta or iliac arteries (Three of our 5 patients); Crawford III: All renal arteries have an anomalous origin. (One of our 5 patients). The patients with horseshoe kidney can also have two separated, or one connected excretory urinary systems. All our 5 patients had two separated ureters. There is no specific clinical manifestation of the horseshoe kidney. Urinary infection or calculosis are very frequent as are in other urinary anomalies. The diagnosis of horseshoe kidney is established by Dupplex ultrasonography, CT scan, NMR, radionuclide scintigraphy and angiography. Very often the diagnosis is established occasionally during the examination of aneurysmal and occlusive diseases of the abdominal aorta. In cases of AAA or AIO associated with horseshoe kidney preoperative vascularization and condition of the excretory system should be established. Besides standard translumbar aortography selective renovasography is often neccessary. In some cases the intraoperative angiography or arterial identification, with metallic probe must be done. All renal arteries are "terminal" without significant anastomosis on the side of the kidney. Therefor its preservation is neccessary. There are three ways. The first is the location of anastomosis (3 of our patients). The second is an AxFF bypass, but only in patients with AIO (One of our patients and in the third reimplantation of the renal artery using Carrel patch technique was performed (One of our patients). The Isthmus of the kidney aggravates aortic preparation especially in patients with AAA. Sometimes isthmectomy is neccessary. In such cases there is danger of urinary fistula. Therefor many authors suggest the left extraperitoneal approach to abdominal aorta. In our patients, the transperitoneal approach was used, isthmectomy was not neccessary and graft was placed behind the isthmus. The operation of the abdominal aorta in patients with horseshoe kidney can be difficult due to anomalous renal arteries, anomalous excretory urinary system and is Ehmus. In these patients a more precise preoperative diagnosis is neccessary.

Evaluation of asynchronous left ventricular relaxation by Doppler echocardiography during ventricular pacing with AV synchrony (VDD): comparison with atrial pacing (AAI).

The effect of right ventricular pacing on left ventricular relaxation was studied in 13 patients (age 62 +/- 3 years), with the atrial sensing ventricular pacing mode (VDD). A control group of similar age (64 +/- 4 years) consisted of 11 patients with atrial pacing (AAI). The timing of events was determined in both groups at similar R-R intervals (921 +/- 77 ms vs 967 +/- 37 ms). The loading conditions as estimated by peak systolic wall stress (afterload) and end-diastolic left ventricular dimensions (preload) were approximately the same in both groups. The ratio of late to early filling velocities were similar in both groups. Dominant changes were: increased preejection period (142 +/- 13 ms vs 95 +/- 15 ms); and higher velocities of isovolumic relaxation flow (60 +/- 34 cm/s vs 25 +/- 4 cm/s) in patients with ventricular pacing. The isovolumic relaxation time was longer in patients with VDD pacing (127 +/- 14 ms vs 108 +/- 12 ms). Anterior systolic interventricular septal motion (paradoxal motion) was recorded in nine patients with VDD pacing and in none of the patients with AAI pacing. Isovolumic relaxation flow was detected during atrial pacing in five (45%) patients and in 13 (100%) patients during atrial sensing ventricular pacing, indicating asynchronous left ventricular relaxation. This data shows that VDD pacing compared to atrial pacing resulted in an altered activation pattern of the left ventricle, associated with delayed onset, asynchronous contraction with interventricular septal motion abnormalities and prolonged asynchronous left ventricular relaxation with abnormal motion manifested by the presence of isovolumic relaxation flow.

[The importance of the sonographic image in the differential diagnosis of acute rejection in kidney transplantation]. / Znacaj sonografske slike u diferencijalnoj dijagnostici akutnog odbacivanja transplantisanog bubrega.

Between October 1987 and October 1992 110 biopsies of transplanted kidney. Histologic examination showed 36 cases of acute rejection (Ac), 19 cases of chronic rejection (Chr), 16 cases of acute tubular necrosis (ATN) and 39 cases of cyclosporin nephrotoxicity. Sonographic characteristics as: hyperechogenicity of the cortex, hypoechogenicity of central pyelovascular zone, large and sonolucent pyramids, spherical configuration of renal allograft, were coelating with histologic and relevant clinic sings of disease. The results show statistically significant correlation with sonographic sings of acute rejection and relevant histologic and clinical findings. There was no correlations in other groups of diseases. These results confirm ultrasound as the primary imaging tool and an invaluable diagnostic modality in the renal transplant patient.

[Urinary system tumors in patients with endemic nephropathy on chronic hemodialysis]. / Tumori urinarnog sistema kod bolesnika s endemskom nefropatijom i na hronicnoj hemodijalizi.

We studied 161 patients who started dialysis from January 1st 1979 to December 31st 1993. Out of 79 males, 26 (32.91%) had the diagnosis of urothelial tumors, and out of these 22 patients (84.61%) had tumors of the upper urothelium. Twenty one (80.76%) of the patients were operated. The predialysis period starting with tumor diagnosing was 61.92 months averaging. The average survival of these hemodialysed patients was 46.07 months. Out of 82 females, 22 (26.82) had tumors of the urinary tract, and out of these 21 patients (95.45%) had tumors of the upper urothelium. Eighteen (81.81%) of them were operated. The predialysis period starting with tumor diagnosing was 84 months, on the average. The average survival was 37.39 months. The results confirm high frequency of tumors of the upper urothelium in patients with endemic nephropathy.

[Renal size as an ultrasonographic parameter in the differential diagnosis of primary and secondary glomerulopathy]. / Velicina bubrega kao ultrasonografski parametar u diferencijalnoj dijagnozi primarne i sekundarne glomerulopatije.

Between October 1987. and October 1992. 289 biopsies of the kidney in patients with glomerular diseases were performed. Pathohistologic analysis showed 218 cases with primary and 71 cases with secondary glomerular diseases. In all patients kidneys were measured by ultrasound examinations. The results showed significant difference in longitudinal diameter of kidneys in patients with primary from those with secondary glomerular diseases. These results can help a nephrologist to diagnose glomerular disease.

[Idiopathic membranoproliferative glomerulonephritis (structural-functional relationship)]. / Idiopatski membranoproliferacioni glomerulonefritisi (strukturno-funkciona zavisnost).

We investigated 12 patents with idiopathic membranoproliferative glomerulonephritis. Discriminatory analysis was used for structural functional relationship in order to determine discriminatory power of certain clinical and pathohistological parameters. Semiquantitatively were determined pathohistological parameters: glomerular index in range 0-10, vascular index 1-4, interstitial fibrosis 0-10, interstitial infiltration 0-3, tubular atrophy 0-3. Nephrotic syndrome (symbolic value), quantitative proteinuria and creatinine clearance (continual variable) were used as clinical parameters. Discriminatory power was determined as a degree of decreasing Shennon's entropy dy distinction of patients according to value of creatinine clearance at the time of biopsy. Discriminatory power was measured in the information measurement units (bit). The most powerful was glomerular index (discriminatory power 0.29) in moderately reduced glomerular filtration rate (creatinine clearance 80 ml/min) at the time of biopsy. In severely reduced glomerular filtration rate (creatinine clearance 40 ml/min) vascular index had the greatest discriminatory power (0.24) while interstitial infiltration and interstitial fibrosis had less powerful discriminatory power (0.13). Negative predictive value of reduced glomerular filtration rate at the time of biopsy in membranoproliferative glomerulonephritis has been confirmed in other studies.