Biomedical subjects
Publications and source records attributed to B Nerstrom.
Urethral pressure profile measurements were performed in 45 men suffering from micturation disturbances with the aim of evaluating the diagnostic aid of the procedure as compared to conventional urodynamic evaluation. The urethral pressure profile seems to be of value in visualizing the diseases of the prostate and the bladder neck, but it is of no definite aid except for postprostatectomy incontinence.
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Under halothane anesthesia, peroperative electromyography of the pelvis and ureter together with intrapelvic pressure and urine flow were recorded in 11 pigs; the electromyography was by bipolar extracellular leads. Pressure waves of low amplitude, synchronous with action potentials from leads placed most proximally in the pelvis, preceded action potentials registered by distally placed leads. Transmission of the action potentials from the pelvis to the ureter took place with a constant transmission velocity but the transmission ratio varied from 1:1 to 6:1. Ureteral electric activity was time-related to the urine bolus. The transmission velocity was smaller in the pelvis than in the ureter and seemed to accelerate caudally. Thus, there is electromyographic evidence that the renal pelvis controls ureteric activity and that this pacemaker function is mediated high up, most proximally, in the renal pelvis.
Renal pelvic function of Danish Landrace pigs under anesthesia was analyzed during "normal" and forced diuresis. Measurements were made of intrapelvic pressures, electromyogram recordings were taken from the pelvis and ureter, and bolus formation was followed. During constant diuresis, pelvic activity displayed a dominant frequency which varied between individuals. When pressure rose or fell, pelvic activity increased or decreased in proportion to the speed rather than the extent of the pressure change. Thus, after furosemide administration urine flow increased and pelvic pressure rose; and in association with the pressure rise, pelvic activity increased significantly when mean pelvic activity in the phase of steep pressure rise was compared with the mean activity over the last 5 min of the observation period before induction of diuresis. Thereafter, pelvic activity decreased despite maintenance of a higher pressure plateau than that in the initial low diuresis observation period. This mode of function can be explained by reference to the characteristics of smooth muscle. Postulation of a specific pacemaker is unnecessary.
Hydrostatic pressure treatment as described by Helmstein was given to 12 patients with hematuria secondary at irradiation for carcinoma of the bladder. The bladder function was evaluated on the basis of urodynamic examinations before and after the treatment. The study includes examination of the effect on the renal function. In 6 patients, hemostasis was obtained for a period averaging 10 months. No serious complications occurred. Following irradiation, the patients showed a characteristic micturition pattern with a small bladder capacity and a marked increase in pressure during the filling phase. The micturition took place partly by use of the abdominal musculature; the detrusor pressure was falling during the whole voiding time. The voiding was almost complete, and the flow values were slightly reduced. The hydrostatic pressure treatment resulted in no demonstrable changes in this micturition pattern. Evaluated from the creatinine clearance, the renal function was unchanged after the treatment, and neither polyuria nor an increased excretion of sodium was demonstrated during the first hours after the treatment. We conclude that before major surgery is decided on, hydrostatic pressure treatment should be given to patients with hemorrhage following irradiation for carcinoma of the bladder. No improvement can be expected in patients where the often pronounced pollakiuria is due to fibrosis of the bladder secondary to irradiation.
Studies were made peroperatively in a patient with incomplete ureteral duplication. Bipolar extracellular EMG-leads were taken from both pelvices, both ureteral segments and from the common ureter. Simultaneously pressure measurements were made in the pelvices. Function of the two pelvi-ureteral units were shown to be autonomous. Simultaneous action potentials and pressure waves were observed in each pelvis. Not every pelvic impulse was transmitted to the corresponding ureter, but when transmission did occur, the conduction rate was constant. Impulses from both ureteral branches were conducted distally to the common ureteral trunk, but impulses from the dilated segment had not the same quality (amplitude) as those from the non-dilated segment. Antiperistalsis was not observed. There was a measurable pressure difference between the two segments.
Pelvi-ureteric function was studied in pigs with experimental urinary tract obstruction, and again, 5 weeks after relief of the obstruction. Study parameters comprised EMG records taken from pelvis and ureter, measurements of intrapelvic pressure and urine flow, and some supplementary studies of renal function. Total obstruction of 5 and 6 weeks duration induced by cuffing the proximal ureter occasioned severe hydronephrosis and renal failure. Pelvic peristaltic activity was of low frequency, and abnormality was clearly more marked after the longer period of obstruction. There was, for example, some preservation of pelvi-ureteric synergism at 5 weeks, but at 6 weeks ureteric activity was wholly autonomous. Pelvic function was similarly isolated, and non productive. Inspection 5 weeks after reconstruction by pelvis resection and neo-anastomosis of the ureter showed continued absence of renal function and no restitution of normal peristaltic patterns. Partial obstruction, effected by implantation of the ureter in the psoas muscle, induced mild pelvic dilatation and impaired renal function, but there were only minor signs of disruption of normal anterograde pelvi-ureteric activity - irregularities, pauses in activity, and double activity complexes. When the ureter was freed functional patterns returned to normal. Both during obstruction and after relief, pelvic pressure increases during forced diuresis were the equivalent of or lower than the pre-determined norm. Cautery at the pelvi-ureteric junction destroyed the musculature and induced a progressive (fibrous stenosis. There was progressive dissociation of pelvi-ureteric activity, total when obstruction was total in which case ureteric activity was only autonomous, and partial when obstruction was partial in which case varying degrees of synergism and autonomous activity were seen. Successful reconstruction (pelvic resection and neo-anastomosis of the ureter) restored an apparent synergism in pelvi-ureteric function.
Intravenous urography and isotope renography studies were made in 54 patients with hydronephrosis. Thirty six of these patients underwent reconstructive surgery and were also studied postoperatively. Both studies gave more or less consistent results - that is to say evaluations of renal function and drainage from each individual study were similar - but no individual parameter was of any specific significance in the selection of patients for therapy. Points were allocated to each parameter, and after summing these points for each individual patient, 3 groupings became apparent: a low count group - patients with pelvectasia but normal renal function:a middle count group - patients with certain hydronephrosis; and a high count group with severe hydronephrosis, and markedly impaired renal function. Post-operatively, renal function was unaltered or mildly reduced in group 1, and improved in groups 2 and 3, though the differences were not statistically significant. It was hoped that the studied would allow differentiation between patients of the low count group, but the conundrum remains - which of them can be categorized as normal variants, and which were in fact displaying early pathological signs of essentially progressive disease.
In 31 patients undergoing surgery in treatment of hydronephrosis, peroperative pelvic pressure measurements were made. EMG records were taken from pelvis and ureter, and occasional measurements of urine flow were made. In 6 instances these studies were also made in the contralateral "normal" kidney, but in 2 of these patients the diseased kidney was not studied. Pelvic pressure during antidiuresis in these 6 "normal" kidneys was about 5 mmHg, and pelvic activity of frequency 5/min. Pelvi-ureteric impulse transmission was anterograde and conduction times were constant. Conduction ratios varied. During forced diuresis mild pelvic pressure rises were seen together with transient increase in pelvic activity over the period of pressure increase. In the studies of hydronephrotic kidneys no significant differences were seen in pelvic pressure of frequency of pelvic activity compared with the "normal" kidney studies, but impulse transmission was markedly disturbed, manifest by varying conduction times, and, on occasion, total dissociation of activity within the pelvis, and between the pelvis and ureter. The more severe the degree of hydronephrosis, the more marked the disturbance. The findings are similar to those made in experiments with pigs after establishment of varying degrees of urine flow obstruction.
The study comprises 16 patients who during the period 1965-1972 underwent mucosal denudation (stripping) for multiple, highly differentiated, non-invasive bladder papillomas. No major complications to the operation were seen. In 3 of the 16 patients histological examination of the operative specimen revealed a more malignant tumour than found on preoperative biopsy. During the observation period, which averaged 4 years, the disease recurred in 10 of the 16 patients. In 4 of them, repeated biopsy showed a more malignant tumour than did the operative specimen. The study moreover demonstrated that following mucosal stripping, pronounced bladder contracture occurred in all the patients and dilatation of the upper urinary tracts in half of them. These serious complications mean that even if the disease does not recur, a reasonably normal life for the patient is unattainable. The method, consequently, cannot be recommended.
Cutaneous uretero-ileostomy was performed on 59 patients previously given irradiation at a dose of 6000 rads as a curative treatment. In 47 patients the urinary diversion was combined with total cystectomy. The indication for operation was residual tumour and/or subjective symptoms. It is concluded that radical surgery following super-voltage radiotherapy is possible, but implies a high lethality and severe complications. The prognosis is especially poor in patients who at the time of surgery have invasive malignant tumours. In our opinion, the operation should be done only if necessitated by severe subjective symptoms and not on the sole indication of residual tumour.
A patient with partial duplication of the inferior vena cava and a retrocaval ureter was preoperatively studied by uro-cavography and renography. Peroperatively intrapelvic pressure measurements were made, and simultaneous EMG recordings were taken from the pelvis, and from the ureter proximal and distal to the retrocaval segment. The electrophysiological activity was normal with normal anterograde impulse transmission. Renal pelvic pressure and pressure increase during forced diuresis was within a normal range.
Renal vein renin ratios were determined in hypertensive patients, 19 with renal artery stenosis, 7 with renal artery occlusion and 13 with unilateral renal hypoplasia. Twenty-one of these patients were treated surgically. Renal vein renin ratios of greater than or equal to 1.5 were associated with high frequency of operative success, but ratios less than 1.5 by no means excluded good surgical results.
During the period 1968-75 310 cadaver kidney transplantations were carried out; 261 first-time, 45 second-time and 4 third-time transplantations. Graft survival after 5 years was about 30% for both the first and the second transplant. Patient survival after 5 years was about 50%. No relationship could be found between match grade and graft survival whereas the patient survival was definitely better in the younger age groups. The major cause of graft loss was rejection, vascular and ureteral complications being less frequent. The main cause of lethal outcome was complications to the immunosuppressive therapy and to a lesser degree cardiovascular events and malignant disorders. Cadaver kidney transplantation is an acceptable treatment of chronical renal failure particularly in younger persons and in cases where dialysis treatment is difficult.
The cumulative graft survival after 355 cadaver kidney transplantations was analyzed with special reference to the age of the donors. A significant decrease in cumulative graft survival with increasing donor age was found.
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