John H. Clorius

Renal artery aneurysm: surgical indications and results.

The clinical course of 23 patients with 28 renal artery aneurysms (RAAs) is reported. The RAAs were recorded over a period of 10 years. Thirty-five per cent of the RAAs (eight of 23 patients) were detected during the investigation of hypertension, whereas 26% (six of 23 patients) were discovered incidentally while imaging atherosclerotic arterial disease in the aorto-iliac region by angiography. Twenty-two aneurysms were treated surgically and primary nephrectomy was necessary in one case. The surgical technique used was excision of the aneurysm with bypass grafting in 13 cases (seven Dacron, five vein, one arterial bypass), a running suture following aneurysm excision in four cases and an end-to-end anastomosis in two cases. The results (for a period of 1-10 years) were excellent in all but three cases: two early graft occlusions (vein interposition) and one late occlusion (Dacron bypass) in the course of a re-operation which had become necessary because of a ruptured aneurysm of the gastro-epiploic artery after 3 months. Three of 23 patients were treated by embolisation of four intraparenchymal aneurysms. The follow-up of a non-treated saccular aneurysm showed a total thrombosis of the aneurysm within 4 years and fixed renal hypertension developed later in this patient. We suggest surgical repair of an RAA regardless of its size and the clinical symptoms, in order to prevent microembolism into the renal parenchyma and to avoid the development of fixed renal hypertension. Intrarenal aneurysms can be treated by embolisation to stop severe haematuria thus preserving the kidney.(ABSTRACT TRUNCATED AT 250 WORDS)

MR to assess renal function in children

Abstract.Renal function evaluation in the pediatric patient is generally based on scintigraphic examinations where a baseline gamma-camera renography is used to determine single kidney function, and diuresis renography is obtained to assess urinary drainage from the pelvicalyceal system. Magnetic resonance imaging also permits the evaluation of renal functional processes using fast dynamic sequences. Principally, an agent cleared by renal excretion is intravenously injected and its cortical uptake, parenchymal transport, and eventually its urinary excretion are followed with serial images. Different approaches have been presented most of which are based on T1-weighted gradient-recalled echo sequences with short TR and TE and a low flip angle obtained after intravenous injection of Gd-DTPA or Gd-DOTA. These techniques permit renal functional assessment using different qualitative and quantitative parameters; however, most of these methods are not suitable for the evaluation of urinary tract dilatation in infants and children. For the diagnostic work-up of children with congenital urinary tract obstruction and malformation a technique was developed which permits quantitative determination of single kidney function, in addition to evaluating urinary excretion disturbances analogous to that possible with scintigraphy.

Diuretic renography in hydronephrosis: renal tissue tracer transit predicts functional course and thereby need for surgery

PurposeThe recognition of those hydronephrotic kidneys which require therapy to preserve renal function remains difficult. We retrospectively compared the ‘tissue tracer transit’ (TTT) of 99mTc-mercaptoacetyltriglycine (99mTc-MAG3) with ‘response to furosemide stimulation’ (RFS) and with ‘single kidney function < 40%’ (SKF < 40%) to predict functional course and thereby need for surgery.MethodsFifty patients with suspected unilateral obstruction and normal contralateral kidney had 115 paired (baseline/follow-up) 99mTc-MAG3 scintirenographies. Three predictions of the functional development were derived from each baseline examination: the first based on TTT (visually assessed), the second on RFS and the third on SKF < 40%. Each prediction also considered whether the patient had surgery. Possible predictions were ‘better’, ‘worse’ or ‘stable’ function. A comparison of SKF at baseline and follow-up verified the predictions.ResultsThe frequency of correct predictions for functional improvement following surgery was 8 of 10 kidneys with delayed TTT, 9 of 22 kidneys with obstructive RFS and 9 of 21 kidneys with SKF < 40%; for functional deterioration without surgery it was 2 of 3 kidneys with delayed TTT, 3 of 20 kidneys with obstructive RFS and 3 of 23 kidneys with SKF < 40%. Without surgery 67 of 70 kidneys with timely TTT maintained function. Without surgery 0 of 9 kidneys with timely TTT but obstructive RFS and only 1 of 16 kidneys with timely TTT but SKF < 40% lost function.ConclusionDelayed TTT appears to identify the need for therapy to preserve function of hydronephrotic kidneys, while timely TTT may exclude risk even in the presence of an obstructive RFS or SKF < 40%.

Radioisotope therapy of cystic craniopharyngeomas

Eighteen patients suffering from cystic craniopharyngeoma were treated with intracavitary irradiation. The beta-emitting radioisotope 90y (2.25 MeV) was instilled into the cyst following stereotactic puncture of the space-occupying lesion. The surgical approach was planned using angiograms and reconstructed transmission computer tomography (TCT) coronal and saggital sections. Therapy was devised to deliver 20,000 rad to the cysts wall. Eleven patients received follow-up TCT examinations after four months. Eight of 11 patients had a significant volume decrease in the craniopharyngeoma cyst. In two patients, the cystic volume remained unchanged; one had progression of disease. It is concluded that the intracavitary treatment of cystic craniopharyngeoma will result in a reduction of the size of the space-occupying lesion.

Diuretic Renography in Hydronephrosis: Delayed Tissue Tracer Transit Accompanies Both Functional Decline and Tissue Reorganization

The significance of delayed tissue tracer transit (TTT) of 99mTc-mercaptoacetyltriglycine (99mTc-MAG3) has not been systematically evaluated in hydronephrosis. We sought to demonstrate that delayed TTT accompanies both functional decline and histomorphologic restructuring. Methods: Twenty 2- to 3-mo-old piglets with surgically induced partial unilateral ureteral stenosis were examined with magnetic resonance urography (MRU) to evaluate morphology and with 99mTc-MAG3 diuretic renography (DR) to determine single-kidney function (SKF), evaluate the response to furosemide stimulation (RFS), and assess TTT. All animals had DR and MRU before and after surgery and a third DR after surgery. Piglets were sacrificed after the final DR for renal histology. A total histologic score (THS) was generated. Results: Preoperative DR demonstrated nonobstructive RFS, timely TTT, and balanced SKF in all 20 kidneys. After ureteral ligature, MRU demonstrated pelvic dilatation in all piglets. The postoperative DRs revealed 12 kidneys with delayed TTT in one or both follow-ups. In these 12 kidneys, the SKF declined from 51% ± 4% to 18% ± 14%, and the THS was 9.0 ± 4.0. Three kidneys always had timely TTT, balanced SKF, and a THS of 1.8 ± 0.3. The contralateral, nonoperated kidneys had timely TTT and a THS of 1.2 ± 0.9. Postoperative scintigrams showed that 3 of 8 kidneys (38%) with an obstructive RFS had timely TTT, which demonstrates that TTT and RFS are not equivalent. Conclusion: In hydronephrosis, a delayed TTT of 99mTc-MAG3 accompanies both functional decline and histomorphologic restructuring in obstruction. According to the literature, a delayed TTT is determined by the filtration fraction of the kidneys and appears to identify an obstruction-mediated upregulated renin-angiotensin system.

Exercise Activates Renal Dysfunction in Hypertension

A bilateral, exercise-mediated renal functional abnormality was first described more than a decade ago. The disturbance is specific for hypertension, is seen in different forms of hypertension, and has been studied most extensively in hypertensives with renovascular disease. The bilateral-abnormal exercise renogram identifies the disturbance. Hypertensives with unilateral renovascular disease were studied in the continuing evaluation of the bilateral function disturbance. We examined 31 hypertensives with documented unilateral renovascular disease, all of whom had renography at rest and during 60 to 80 W ergometric exercise. An additional seven normotensives and 17 essential hypertensives served as controls, and had the same sequence of studies. All patients reported upon continued on to an infusion clearance with 131I-hippurate and 111In-diethylenetriamine pentaacetic acid to determine glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) at rest, and during 25 W ergometric exercise. Eighteen of 31 hypertensives with unilateral renovascular disease were found to have a bilateral-abnormal exercise renogram. Clearance examinations in these identified a prominent reduction of the GFR and a lesser decrease in the ERPF during exercise. Hypertensives with normal exercise renograms did not have the exercise mediated abnormal clearance pattern. Similar results were observed in the control population of essential hypertensives, 65% of whom developed the functional disturbance. The seven normotensives controls did not exhibit the exercise mediated function changes. We conclude that an exercise-mediated bilaterally occurring functional disturbance exists in certain hypertensives, who then have a bilateral-abnormal exercise renogram. Associated with this is a distinctly abnormal clearance during exercise which is characterized by a low filtration fraction.

Contribution of paramagnetic trace elements to the spin-lattice relaxation time in the liver.

The relaxation times of water protons in rat liver tissue were measured with a NMR spectrometer at 20 MHz. The paramagnetic trace elements Cu, Fe, and Mn were determined by neutron activation analysis. No shortening of T1 could be observed when liver Cu or Fe concentration was increased in the microgram range. T1 was strongly correlated with the liver Mn concentration of untreated animals and animals whose liver Mn concentration was artificially increased or decreased by intravenous injection of manganous acetate or a metal chelating agent with high affinity for hepatobiliary excretion. Deviations from this Mn-T1 correlation were found in the initial phase of liver cirrhosis induced by thioacetamide (elongated T1, normal Mn concentration) and after stimulation of liver growth by phenobarbital (normal T1, decreased Mn concentration). An increased or decreased enhancement factor for Mn may have contributed to the observed deviations during phenobarbital and thioacetamide treatment.

Evidence of Possible Association of Nephrolithiasis and Nephroptosis

Two separate populations, one consisting of 100 patients with renal stones and one consisting of 81 patients with nephroptosis were examined to determine whether an association may exist between excessive renal mobility and renal stone formation. The statistical analysis of the data suggests a direct relationship between nephroptosis and the occurrence of renal stones.

Renal perfusion and mean vascular transit time

A method was developed to determine the mean vascular (arterio-venous) transit time (MVTT) of renal transplants. The renal transit times were calculated from perfusion curves obtained when grafts were examined with 99mTc-DTPA. About 400 examinations were performed during a 6-month period. As a result, influences of clinical complications on transit times were demonstrated. It was found that the individual MVTT is not a suitable parameter for assessment of renal grafts since individual transit times vary widely.

Electrophilic radioiodine exchange labeling in aqueous solutions

Abstract A new mechanism, combined with a new technique of radioiodine exchange labeling is presented. Temperature sensitive, iodine containing organic compounds can be labeled in this way as well as molecules with moderate reactivities. The labeling procedure was optimized with special respect to the required minimal reaction time and temperature.