PubMed Health⌕ Search

Biomedical subjects

R van Schilfgaarde

Publications and source records attributed to R van Schilfgaarde.

At least 91 records · Page 5Linked to original sources
PubMed1987

Surgical treatment of renovascular hypertension caused by arteriosclerosis. II. Influence of preoperative risk factors and postoperative blood pressure response on late patient survival.

This study assesses the late survival of 103 patients with renovascular hypertension caused by arteriosclerosis who underwent reconstructive surgery during the period of 1959 through 1982. It provides a detailed analysis of the influence of preoperative factors and the postoperative blood pressure response to fatal and nonfatal cardiovascular events during follow-up. All patients suffered from severe hypertension. Arteriosclerosis was limited to the renal arteries in 52% of the patients, while 48% showed overt extrarenal arteriosclerosis. Hypertensive target organ damage was present in 68% of the patients. At a mean of 8.5 months postoperatively, 80% of the patients showed beneficial and 20% showed unsatisfactory blood pressure responses. These results were not related to the presence or absence of extrarenal arteriosclerosis. Overall, late (10 years) patient survival was significantly lower than the expected survival of a reference population (79% versus 92%; p less than 0.0001). Late patient survival was not influenced by the absence or presence of extrarenal arteriosclerosis (82% versus 82%) or target organ damage (83% versus 82%), but late survival was significantly better with beneficial (87%) than with unsatisfactory blood pressure responses (67%). This effect was especially conspicuous in the presence of extrarenal arteriosclerosis (88% versus 57%; p = 0.04) but not in its absence (86% versus 74%; p = 0.41). In terms of long-term survival, these findings clearly demonstrate the favorable effect of successful surgical treatment of patients with renovascular hypertension caused by arteriosclerosis. Moreover, they illustrate that the mere presence of preoperative extrarenal arteriosclerosis or target organ damage is not sufficient argument against surgical therapy.

Adult↗
PubMed1987

Surgical treatment of renovascular hypertension caused by arteriosclerosis. I. Influence of preoperative factors on blood pressure control early and late after reconstructive surgery.

This study evaluates the long-term efficacy of reconstructive surgery for renovascular hypertension caused by arteriosclerosis, which was performed on 112 patients from 1959 to 1983. Despite medical therapy, all patients had persistent hypertension, with a mean preoperative blood pressure of 188/113 mm Hg. Their median age was 49 years, and the median duration of objectively documented hypertension was 21 months at the time of surgery. Manifestations of extrarenal arteriosclerosis (ERA) were present in 57 patients (51%). Results were evaluated both at a short-term (ST) interval (mean: 8.4 months) and at a long-term (LT) interval (mean: 8.9 years) postoperatively. Patients were classified by means of strict criteria as cured, improved, or unsuccessfully treated. If a patient was cured or if his condition improved, this was considered a beneficial blood pressure response. Beneficial responses were maintained during LT follow-up, since the respective percentages for cure and improvement were 24% and 50% at the ST interval and 18% and 61% at the LT interval. These results had not been influenced by either older age or the presence of ERA, since results were similar in patients older and younger than the median age and in those with and without ERA. The preoperative duration of hypertension was the only pertinent clinical feature that influenced the LT interval results, LT beneficial responses were observed in 95% of the patients with a shorter duration and in 78% of those with a longer duration of preoperative hypertension than the median (p = 0.01). We conclude that surgical therapy for renovascular hypertension caused by arteriosclerosis can effectively reduce blood pressure and that this result is maintained during LT follow-up. In terms of anticipated blood pressure response, older age, longer duration of hypertension, and the presence of ERA do not exclude surgical therapy.

Adult↗
PubMed1987

Long-term results of in situ and extracorporeal surgery for renovascular hypertension caused by fibrodysplasia.

In this study the early and late results of surgical reconstruction for renovascular hypertension caused by fibrodysplasia are evaluated in 53 patients treated between 1962 and 1983. There were 40 female and 13 male patients. The mean blood pressure was 208/126 mm Hg before medical therapy and 171/109 mm Hg thereafter. Bilateral renal artery stenoses were present in 12 patients. In situ revascularization was used in 26 patients and extracorporeal surgery to repair branch artery lesions was performed in 27 patients. Surgical therapy reduced the blood pressure to normal levels with minimal antihypertensive medications. This effect was already apparent 6 to 12 months after operation (mean blood pressure level of 140/90 mm Hg) and it was maintained during a mean follow-up period of 8.4 years (range 1 to 20 years) (mean blood pressure level of 134/85 mm Hg). At 6 to 12 months after operation, 79% of the patients were classified as either cured or improved. At this time the results did not appear to have been influenced by the preoperative duration of hypertension, nor by manifestations of extrarenal arteriosclerosis (ERA) as found in 10 patients, or by the surgical technique applied. But at the end of the long-term follow-up period (mean 8.3 years) the beneficial response rate of 87% appeared to have been adversely influenced by the presence of preoperative ERA, since beneficial response rates were 93% for those without and 67% for those with ERA (p = 0.17). We conclude that renal revascularization is effective both early and late for the treatment of renovascular hypertension caused by fibrodysplasia and that complex renovascular obstruction can be treated effectively with extracorporeal repair.

Adolescent↗
PubMed1985

The effects of duct obliteration and of autotransplantation on the endocrine function of canine pancreatic segments.

This study in dogs addresses itself to the endocrine function of the duct-obliterated left pancreatic lobe (body and tail), which is the portion of the pancreas used for segmental transplantation. The endocrine function was determined with intravenous (i.v.) glucose tolerance tests and expressed in K-values and insulin-response curves. Duct obliteration of the nontransplanted left lobe was associated with normal K-values in the presence of the unmodified right lobe, but with reduced K-values in its absence. Removal of the left lobe while leaving the right lobe untouched was not associated with reduced K-values, but duct obliteration of the whole pancreas was. When the duct-obliterated left lobe was transplanted onto the iliac vessels (segmental autografts), K-values were reduced when compared with the unmodified situation, but were significantly higher than with nontransplanted, duct-obliterated left lobes. Insulin-response curves of nontransplanted, duct-obliterated segments differed both qualitatively and quantitatively from the unmodified situation, but insulin-response curves of duct-obliterated segmental autografts showed only qualitative differences with the unmodified situation. It is concluded that duct obliteration rather than the absence of the right lobe is the predominant cause of reduced glucose tolerance with duct-obliterated left pancreatic lobes. It is suggested that duct obliteration affects the endocrine pancreas both in a qualitative and quantitative fashion. The qualitative effect is similarly demonstrable with segmental autografts and nontransplanted segments, but the quantitative effect is largely dissolved with autografting by virtue of caval as opposed to portal venous drainage.

Animals↗
PubMed1984

The effect of duct obliteration on the histology and endocrine function of the canine pancreas.

Although duct obliteration is a safe and effective method for ablation of exocrine secretion in segmental pancreas transplantation, it remains to be clarified whether its effects are restricted to the exocrine tissue. In 20 dogs (beagles 9-15 kg) the right lobe of the pancreas was removed and the ductal system of the left lobe was injected with the duct-obliterants neoprene (6 dogs), polyisoprene (6 dogs), or prolamine (8 dogs). In this study, i.v. glucose tolerance tests (the results of which are expressed in K values) and relaparotomies for taking biopsies were performed at 1, 3, and 12 months after duct obliteration. Biopsies were studied histologically and immunohistochemically in a qualitative and semiquantitative fashion. Three prolamine-injected dogs developed diabetes. All other dogs maintained normal fasting blood glucose levels but showed reduced K values at 1 month after duct obliteration. Further deterioration of glucose tolerance was not observed up to 12 months. Differences in K values depending on the type of obliterant were insignificant at all intervals. The exocrine tissue was completely replaced by fibrosis at 3 months after duct obliteration, and the architecture of the islets was disrupted. Morphometrical analysis of relative numbers of different endocrine cell types showed transient changes at 1 month after duct obliteration, but did not differ from unmodified controls at 12 months. We conclude that the effects of duct obliteration are not restricted to the exocrine pancreatic tissue, but that the endocrine pancreas is interfered with as well. Changes in islet function and histology are brought about during the first month after duct obliteration and stabilize thereafter.

Animals↗
PubMed1983

Arterial blood supply of the left lobe of the canine pancreas. II. Electromagnetic flow measurements.

The arterial blood flow through the left lobe of the canine pancreas was assessed by means of electromagnetic flow measurements under three different experimental conditions. First, flow was measured in 14 unmodified left pancreatic segments. The mean segmental blood flow was 9.1 +/- 4.5 ml/min, while the mean blood flow through the splenic artery was 53.3 +/- 21.2 ml/min. Next, flow was measured in seven of these dogs 1/2 hour after occlusion of the ductal system and construction of an end-to-end arteriovenous fistula between the distal splenic vessels. The segmental pancreatic blood flow remained unchanged, and the blood flow in the splenic artery increased more than twofold. Third, flow was measured in seven dogs (eight measurements) at 3 to 8 months after ductal occlusion of the left lobe. No significant decrease in segmental pancreatic blood flow was demonstrable up to 8 months. It is concluded that the arterial blood flow through the left lobe of the canine pancreas amounts to less than 20% of that in the splenic artery, that an end-to-end arteriovenous fistula increases the blood flow through the splenic artery and thus may contribute to the prevention of vascular thrombosis, and that the eventual decrease of endocrine function or occurrence of vascular thrombosis in duct-obliterated pancreatic grafts cannot be readily explained by a reduced blood flow as a consequence of either duct obliteration as such or fibrosis induced by duct obliteration.

Animals↗
PubMed1983

Arterial blood supply of the left lobe of the canine pancreas. I. Anatomic variations relevant to segmental transplantation.

The anatomy of the arterial blood supply of the left lobe of the pancreas was studied in 70 beagles. It was found to be supplied by one small artery only, which was called the pancreatic artery. The pancreatic artery originated from the splenic artery (type I) in 56 dogs (80%). However, it originated from the cranial mesenteric artery (type II) in 14 dogs (20%). In the presence of type I anatomy, the surgical technique for segmental pancreatic transplantation can, in general, be performed in a routine fashion. In the presence of type II anatomy, a modification should be applied. This modification is described and illustrated. It is concluded that the pancreatic artery should always be identified at operation, and that the specific surgical procedure chosen should depend upon the anatomy found. In addition, ischemic necrosis of segmental pancreatic grafts can only be explained by vascular thrombosis if the pancreatic artery has been recognized and preserved with certainty at transplantation.

Animals↗
PubMed1983

The persisting capability for vasodilatation in duct-occluded canine pancreatic segments.

The effect of duct-obliteration and duct-obliteration induced fibrosis on the capability for vasodilatation of the pancreatic vasculature was investigated in dogs. It was demonstrated that the increase of basal blood flow through left pancreatic segments, induced by intra-arterial injection of papaverin, remained unchanged during 6 months after duct-obliteration. It is concluded that impairment of endocrine function of duct-obliterated segmental pancreatic grafts cannot be readily explained by a functional impairment of the pancreatic vessels.

Animals↗
PubMed1981

Uremic escape of renal allograft rejection.

It is demonstrated in rats that, in the presence of early postoperative severe but transient uremia, the survival of first set Brown-Norway (BN) renal allografts in Lewis (LEW) recipients is at least three times prolonged when compared to non-uremic controls. This phenomenon is called "uremic escape of renal allograft rejection'. By means of lethal X-irradiation of donors of BN kidneys transplanted into transiently uremic and non-uremic LEW recipients, the presence of passenger lymphocyte immunocompetence is demonstrated to be obligatory for this phenomenon to occur. As a result of mobile passenger lymphocyte immunocompetence, a graft-versus-host (GVH) reaction is elicited in the spleens of LEW recipients of BN kidneys which amplifies the host response. The splenomegaly observed in LEW recipients of BN kidneys is caused not only by this GVH reaction, which is shown to be exquisitely sensitive to even mild uremia. It is also contributed to by a proliferative response of the host against the graft (which latter response is equated with an in vivo equivalent of a unilateral mixed lymphocyte reaction (MLR)), since the reduction in spleen weights caused by abrogation of mobile passenger lymphocyte immunocompetence brought about by lethal donor X-irradiation is increased significantly by early postoperative severe but transient uremia. It is concluded that in uremic escape of renal allograft rejection both reactions are suppressed by uremia during the early postoperative period. Prolonged survival is brought about, since on the one hand suppression of the splenic GVH reaction abolishes its amplifying effect on the host response, and on the other hand suppression of the splenic MLR equivalent interferes with the generation of cytotoxic T-lymphocytes and enhances the generation of suppressor cells.

Animals↗
PubMed1981

Extracorporeal renal surgery.

By means of techniques derived mainly from renal transplant surgical experience, several pathologic conditions of the renal artery, the kidney and the ureter have been made accessible to surgical therapy in the course of the past two decades. This therapy is basically composed of nephrectomy, workbench surgery and reimplantation of the kidney, in this order, and called "extracorporeal renal surgery'. Indications for its use are proposed and discussed, and the operative technique is described. Results are presented of 27 extracorporeal vascular reconstructions in 25 patients with severe renovascular hypertension on the basis of fibromuscular dysplasia located predominantly peripherally in the renal artery and its branches. Of these procedures, 25 were actually completed since in two patients reconstruction of the renal artery was technically impossible and reimplantation of their kidneys had to be discarded. One out of the other 23 patients died because of haemorrhagic and septic complications. In the remaining group of 22 patients, operation-associated complications were observed in one patient, who had to be reoperated because of bleeding at the operation site. At a mean follow-up period of 4.5 years, all these 22 patients had normal blood pressures, and 16 were off medication ("cured') whereas six needed only moderate anti-hypertensive medication ("improved'). Results are also presented of extracorporeal procedures performed in one patient with a carcinoma in a solitary kidney and in one patient with a ruptured aneurysm of the abdominal aorta in which both renal arteries were involved. Both patients are well at one and more than five years postoperatively, respectively.

Adolescent↗
PubMed1981

Acute acalculous cholecystitis.

Acute acalculous cholecystitis after trauma or non-related surgery is a rare and dangerous complication. The pathogenesis is multifactorial. Impairment of the circulation to the gallbladder and cystic duct obstruction by inspissated bile seem to be the most important factors. The disease runs a fulminant course, and since diagnosis is generally difficult and usually delayed, the mortality is unduly high. Awareness of the physician is therefore of paramount importance. Cholecystectomy is the recommended treatment. A series of 13 patients is presented and the pathogenesis, diagnosis, and management of this complication are discussed.

Acute Disease↗
PubMed1980

Role of mobile passenger lymphocytes in the rejection of renal and cardiac allografts in the rat. A passenger lymphocyte-mediated graft-versus-host reaction amplifies the host response.

It is demonstrated that passenger lymphocytes migrate out of rat renal allografts into host spleens in a radioresistant fashion. These mobile passenger lymphocytes within BN kidney and heart transplants are immunocompetent, since they elicit a graft-versus-host (GVH) reaction in the spleens of (LEW x BN)F2 hybrid hosts. The greater GVH reaction in (LEW x BN)F1 recipients of BN kidneys reflects the greater number of mobile passenger lymphocytes in the kidney when compared to the heart. The mobile passenger lymphocytes within BN renal allografts also cause a proliferative response in the spleens of LEW hosts as well as an accelerated rejection of BN renal allografts when compared to BN cardiac allografts, for the differences between BN kidney and heart, both in terms of splenomegaly elicited in LEW as well as tempo of rejection, are abolished by total body X-irradiation of the donor with 900 rad. Results indicate that a mobile passenger lymphocyte mediated GVH reaction in the central lymphoid organs of the host augments the host response to allogeneic kidneys and contributes materially to first-set renal allograft rejection; this GVH reaction on the other hand is not conspicuously present in LEW recipients of BN cardiac allografts and has therefore little effect on first-set cardiac allograft rejection.

Animals↗
PubMedDate not supplied

Changing patterns in graduate surgical education in The Netherlands.

An overview is presented of the organization, outline, and contents of graduate surgical training programs in The Netherlands. Adaptations of these programs to changes in demands in surgical practice and health care delivery systems are discussed. Special emphasis is given to the relation of surgery and the surgical specialties, additional training, theoretic training, and manpower planning. The principal questions regarding the optimal way to respond to changing concepts in the field of surgery are presented and discussed in the context of the situation in The Netherlands, but they seem to be similar in the surgical communities of many countries.

Delivery of Health Care↗