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Biomedical subjects

S Nordgren

Publications and source records attributed to S Nordgren.

At least 73 records · Page 4Linked to original sources
PubMed1988

Sympathetic nervous influence on the internal anal sphincter and rectum in man.

The effect of sympathetic nerve block and efferent stimulation of the sympathetic nerves on anorectal motility was studied in 21 patients undergoing operation for rectal carcinoma. Anal pressure and rectal volume were simultaneously recorded before and after epidural anaesthesia and during nerve stimulation. Efferent electrical stimulation of the presacral hypogastric nerves (HGN) elicited a contraction of the internal anal sphincter (IAS) in 13 out of 15 patients. The contraction was preceded by a relaxation in seven patients. In the rectum stimulation of the HGN caused variable responses. A weak contraction was the most frequent response. Efferent stimulation of the periarterial lumbar colonic nerves (LCN) elicited a clear-cut contraction of the IAS, while rectal motor responses were only occasionally observed. Epidural anaesthesia encompassing the thoraco-lumbar region (EDA), when used to block the sympathetic discharge to the IAS and the rectum, caused a reduction of anal pressure (28 +/- 11%) and an increased rectal tone. The results imply that the human IAS receives a sympathetic excitatory innervation via both the HGN and the LCN. Furthermore, it appears that the HGN convey inhibitory fibres to the IAS. The rectal responses to EDA and sympathetic nerve stimulation also indicate the presence of both excitatory and inhibitory neurones in the sympathetic nerve supply to the rectum in man.

Aged↗
PubMed1988

The functional results after colectomy and ileorectal anastomosis for severe constipation (Arbuthnot Lane's disease) as related to rectal sensory function.

Rectoanal manovolumetry during graded isobaric rectal distension was carried out in 12 women with severe constipation classified as slow transit constipation (Arbuthnot Lane's disease). The resting anal sphincter pressure, the rectoanal inhibitory reflex and the rectal capacity were all normal. While the distension volumes required to elicit sensation of rectal filling and an urge to defaecate were within normal limits in all patients the distension pressures required to elicit such sensations fell outside the 95% limits of variation of control subjects in 4 patients. All patients were subsequently subjected to colectomy and ileorectal anastomosis. Patients with normal rectal sensory function had a satisfactory functional result after colectomy, whereas the four patients with blunted sensation did not improve. These findings suggest that rectoanal manovolumetry with determination of the distension pressures required to elicit rectal sensation is an important preoperative measure to be used in patients with severe constipation for selection of patients suitable for colectomy and ileorectal anastomosis.

Adult↗
PubMed1988

Does balloon dilatation and anal sphincter training improve ileoanal-pouch function?

Although patients' satisfaction may be high after restorative proctocolectomy the functional results are still far from perfect. Increased bowel frequency and imperfection in continence are common. Pouch volume and anal sphincter status are important determinants for the outcome. The aim of the present study was to evaluate if balloon dilatation of the pouch and sphincter biofeedback training might improve the results. Forty patients with an ileo-pouch anal anastomosis were randomized into a control and a treatment group. During the interval with a diverting ileostomy, patients in the latter group were subjected to balloon dilatation of the pouch and sphincter biofeedback training by using a manovolumetric technique. All patients were functionally assessed and anorectal manovolumetry performed preoperatively and at regular intervals postoperatively. Follow-up time was at least 12 months. Immediately before ileostomy take down patients in the treatment group showed a significant initial increase in pouch compliance compared with controls. However, a rapid and pronounced increase in pouch volume occurring after ileostomy closure in the control group equalized this initial difference. Anal resting tone and maximum squeezing capacity were at all intervals similar in the two groups. Bowel frequency per 24 h was similar and mucus soiling occurred to a similar extent in both groups, and the overall functional result as assessed according to a scoring system was equal at each interval. Balloon dilatation of the pouch and sphincter exercises appear not to be essential measures in these patients.

Adolescent↗
PubMed1988

Kock's pouch converted to a pelvic pouch. Report of a case.

This study reports a patient previously operated upon with proctocolectomy and construction of a continent ileostomy (Kock pouch). The sphincter muscles, which were preserved by using the mucosal proctectomy technique, were used for conversion to a pelvic pouch five years later. The functional result was satisfactory and superior to that commonly seen in an average J-pouch patient. Patients with a continent ileostomy and in whom the rectum or sphincters have been preserved may be easily converted to a pelvic pouch, should they wish. Patients in whom a short mesentery prevents construction of a pelvic pouch, may be recommended a continent ileostomy as a temporary measure. Due to subsequent expansion of the reservoir, a restorative ileopouch-anal anastomosis may be possible at a later date. The good functional result in this case implies that the double folded reservoir according to Kock's original technique exhibits the same unique reservoir properties even when employed for an ileopouch-anal anastomosis.

Adult↗
PubMed1988

The sympathetic innervation of the internal anal sphincter and rectum in the cat.

The distribution of the sympathetic innervation to the internal anal sphincter (IAS) and rectum and the occurrence of different types of adrenergic receptors in the two organs were investigated in anaesthetized cats. Anal pressure and rectal motility were recorded by a manometric and a volumetric method respectively. Division of both the hypogastric nerves (HGN) and the lumbar colonic nerves (LCN) reduced the anal pressure by 46 +/- 6% of the resting pressure (40.9 +/- 6.4 mmHg) and consistently increased rectal motility. Efferent electrical stimulation of the HGN as well as the LCN elicited a contraction in the anus and the rectum, which, at maximal stimulation, caused the anal pressure to reach a similar level to that recorded before division of these nerves. After injection of phentolamine the anal contraction was abolished, whereas the rectal contraction was either abolished or converted to a beta-adrenergic relaxation. Propranolol caused increased rectal contraction in response to stimulation of the HGN and the LCN, whereas the anal contraction was unaffected. The results imply that the sympathetic nerves exert a tonic excitatory effect on the IAS and a dual effect on the rectum in the cat. The results also indicate that sympathetic fibres to the IAS are conveyed in both the HGN and the LCN. Inhibitory beta-adrenergic receptors seem to be of minor importance in regulating anal pressure.

Adrenergic Fibers↗
PubMed1988

Motor responses elicited by local electrical stimulation of the distal colon in the anaesthetized rat.

A method to study electrically induced distal colonic motility in the rat in vivo is reported. The animals were anaesthetized with methohexital and chloralose and were artificially ventilated. Motility of a segment (2 cm) of the distal colon was monitored as volume changes of an intraluminal balloon, introduced via the anus. Local electrical stimulation of the wall of the segment was achieved by means of a bipolar electrode folded around the gut. Stimulations produced reproducible contractile responses in a frequency dependent fashion. Stimulation characteristics resembled those of other autonomic neuro-effector systems. The adrenergic neuron-blocker, guanethidine, significantly lowered colonic tone, but had no other effects on spontaneous or electrically induced motility. Atropine significantly lowered colonic tone. After the administration of this compound the electrically induced contractions were significantly smaller with a shorter duration and, furthermore, appeared upon the cessation of stimulation ('off' or 'rebound' contraction). Following the administration of tetrodotoxin (TTX, given close i.a. via a cannula with its tip in distal aorta) basal colonic tone and the number of spontaneously occurring contractions increased. The amplitude and duration of the electrically induced responses were significantly attenuated and, furthermore, appeared as 'rebound' contractions which were preceded by a relaxation. Such TTX-resistant responses may be myogenic, but a neurogenic origin cannot be excluded. The present study showed that local electrical stimulation of the distal colon elicits cholinergic contractions, but also atropine- and TTX-resistant motor responses.

Animals↗
PubMed1988

Manovolumetry: a new method for investigation of anorectal function.

A new technique for manovolumetric investigation of rectoanal function allowing for simultaneous recording of rectal volume, anal pressure and external sphincter EMG in response to graded rectal distension was developed. Distension pressure was generated by a water column between two reservoirs. Volume was recorded as shifts of water between the reservoirs. Anal pressure was recorded with a cylindrical balloon and electromyographic activity of the external sphincter by means of a needle electrode. It could be shown that although reduction of preset pressure was minimal, this factor had to be taken into account when rectal compliance is high. The position of the patients during the investigation has to be defined, because rectal volume changed with body position. Pull through studies of anal pressure indicated low sensitivity to displacement of the cylindrical anal probe. A pressure adaptation to the anal probe during eight minutes was noted. Representative recordings of the anorectal response to different isobaric pressures are presented. The present system offers new possibilities for investigation of rectoanal physiology in man.

Adult↗
PubMed1987

Postoperative complications in colorectal surgery in relation to preoperative clinical and nutritional state and postoperative nutritional treatment.

The impact of the pre-operative nutritional and clinical state on post-operative morbidity and mortality is not fully known and the effect of total parenteral nutrition (TPN) on the postoperative complication rate has not been established. We have investigated the effects of postoperative TPN on the complication rate in 92 patients after major colorectal surgery for carcinoma of the large bowel or inflammatory bowel disease in a controlled, randomised study. The complication rate was analysed against seven commonly used nutritional (biochemical and anthropometric) variables and against the diagnosis, clinical inflammatory activity and presence of pre-operative septic complication. Patients were randomly allocated to postoperative TPN or conventional fluid and electrolyte support. The results show no correlation between the complication rate and the nutritional and clinical state of the patients as assessed pre-operatively. The complication rate was not significantly reduced by postoperative TPN. This study indicates that biochemical and anthropometric nutritional variables do not identify patients at risk to develop postoperative complications. The presence of pre-operative complications showed a marginal correlation with postoperative morbidity, in agreement with previous experience. The result of this study obviates the use of TPN in routine postoperative care.

Adult↗
PubMed1987

The immediate and long-term effects of postoperative total parenteral nutrition on body composition.

The short and long-term effects of postoperative total parenteral nutrition (TPN) on body composition were studied in a randomised series of patients undergoing major colorectal surgery. Ninety-two patients (colorectal cancer: 50, ulcerative colitis or Crohn's disease: 42) were grouped according to diagnosis and clinical inflammatory activity. TPN was given for 9.7 +/- 1.1 days. The complication rate was not changed by the TPN. Nitrogen balance was studied during the first week. Body weight, total body potassium, triceps skinfold, serum albumin and body water were measured before and at intervals up to 24 weeks after the operation. Cumulative nitrogen balance in control patients at 7 days after surgery was -47.3 g. Patients given TPN balanced nitrogen intake and output (cancer patients and patients with quiescent inflammatory bowel disease, IBD) or were in positive balance (patients with active IBD). Weight loss at 1 week after surgery was less in TPN patients compared to controls and this difference remained statistically significant up to 6 months after termination of the nutritional treatment. A similar, although not statistically significant, difference was noted in total body potassium and triceps skinfold. Patients with active IBD regained pre-operative body composition earlier than cancer patients and patients with quiescent IBD. It is concluded that TPN after major colorectal surgery reduces postoperative weight loss and that this effect lasts after termination of the nutritional treatment. In the absence of increased body potassium and increased body water, we conclude that the long-term effect of TPN on body weight is most likely due to preservation of fat.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Long-term ileostomy complications in patients with ulcerative colitis and Crohn's disease.

Ileostomy complications in 203 patients operated on with proctocolectomy and ileostomy for ulcerative colitis and Crohn's disease were investigated prospectively. The patients were examined at regular intervals by interview and thorough examination of the stoma. Stomal dysfunction was carefully assessed and patients presenting with surgical complications were admitted for reconstruction. The crude rate of ileostomy complications necessitating reconstruction was 34% and significantly higher in patients with Crohn's disease compared with patients with ulcerative colitis. The cumulative rate of surgical revision after 8 years was 75% in the former group and 44% in the latter. Ileostomy stenosis and sliding recession were the two most common indications for reconstruction. Eighty-three per cent of the revisions were performed as local procedures, making a formal laparotomy unnecessary. Causative factors such as surgical technique, length of concomittant ileal resection and postoperative weight gain were analysed for possible influence on the rate of reconstruction, but no significant association was identified.

Adolescent↗
PubMed1986

Restoration of intestinal continuity (pelvic pouch) after previous proctocolectomy with distal mucosal proctectomy.

Colectomy with full thickness proximal proctectomy and endoanal distal mucosal proctectomy may be a rational alternative to the conventional single stage proctocolectomy for ulcerative colitis. One of the great attractions of the method is that the preserved anal canal and anal sphincters may subsequently be used for restoration of intestinal continuity. Two patients are described who were both successfully treated by construction of a pelvic pouch at a second stage. This approach should be considered an alternative for patients with severe ulcerative colitis particularly those in whom preservation of the rectum is judged to be hazardous.

Adult↗
PubMed1985

The pelvic pouch and ileoanal anastomosis procedure. Surgical technique and initial results.

The pelvic pouch and ileoanal anastomosis procedure should be considered a reasonable alternative for selected patients with ulcerative colitis and familial polyposis. Patients can expect an improved quality of life without a stoma, particularly those with ulcerative colitis. The long-term effects of the reservoir are not completely known; however, from previous reports and from experience with the Kock's ileostomy reservoir, it seems unlikely that there will be a long-term metabolic problems. It appears that a reservoir is essential in adults to minimize stool frequency to an acceptable level and that there is an inverse correlation between pouch size and stool frequency. We still consider this to be an evolutionary procedure and, as such, it should be confined to specialized centers where larger experiences can be accumulated. For the majority of patients who are being considered for proctocolectomy and ileostomy, we urge that they be made aware of alternative forms of therapy and that retaining the rectum should be considered in these patients due to the possibility of reconstructive surgery at a future date.

Adolescent↗
PubMed1985

Cyclosporine absorption in intestinal transplantation.

The absorption of oral cyclosporine (CsA) was studied in a canine small intestinal transplantation model. Absorption of CsA was almost absent in bowel-resected dogs. Autotransplanted dogs showed a persisting malabsorption of CsA (mean peak of 687 +/- 348 ng/ml vs. 1683 +/- 154 ng/ml in control dogs). Allotransplanted dogs with normal graft histology showed a similar malabsorption (mean increase in CsA level: 833 ng/ml), whereas allotransplanted dogs with rejection of the graft showed a markedly decreased absorption (mean increase: 368 +/- 31 ng/ml). In two autotransplanted dogs pretreated with olive oil alone, CsA absorption increased over four weeks to a mean peak of 2215 +/- 5 ng/ml. We conclude that oral CsA is absorbed through the small intestine. Absorption of CsA is decreased after autotransplantation and allotransplantation, and rejection of the graft impedes it further. Regular administration of olive oil alone enhances absorption of oral CsA in a canine model.

Animals↗
PubMed1985

Studies on the integrated extrinsic nervous control of rectal motility in the cat.

The effect of sympathetic nervous activity on rectal motility induced by pelvic nerve stimulation (PNS) was studied in anaesthetized cats. Division of the sympathetic lumbar colonic and hypogastric nerves or alpha-adrenoreceptor blockade, both of which reduced rectal tone, also reversed a predominantly relaxatory pelvic nerve response into a pure contraction. Contractions to pelvic nerve stimulation were reduced by simultaneous lumbar colonic nerve stimulation. This lumbar colonic nerve-induced inhibition was augmented by alpha-adrenoceptor blockade and abolished by beta-blockade. Close intra-arterial injection of a beta-adrenergic agonist reduced contractions to PNS, while an alpha-adrenergic agonist had no effect. Stimulation of the hypogastric nerves enhanced rectal contractions to simultaneous PNS. The apparent similarity with the arrangement of extrinsic nervous control of the internal anal sphincter suggests that the rectum is functionally involved in continence mechanisms.

Adrenergic alpha-Agonists↗
PubMed1984

Morphologic studies of intestinal allograft rejection. Immunosuppression with cyclosporine.

The usefulness of isolated intestinal pouches of an intestinal allograft for monitoring mucosal histology during rejection episodes was studied in a canine model. Total small intestinal autotransplantation was performed in four dogs, and allotransplantation in 18 dogs. Isolated pouches from the proximal and distal ends of the allografts were brought to the skin as stomas. Serial biopsies were obtained from these pouches. Nine allotransplants were treated with a suboptimal dose of cyclosporine. Nine allografted dogs were not immunosuppressed. Biopsies from all animals were normal the first two days postoperatively, and remained so in the autotransplants. Mononuclear cell infiltration in the lamina propria and submucosa was seen up to five days before death from rejection of the allograft in dogs on cyclosporine. At autopsy, all dogs had histologic findings in the transplanted bowel similar to those of simultaneously obtained pouch biopsies. The results show that histologic changes in isolated pouches from intestinal allotransplants reflect changes in the incontinuity segment of the graft and, therefore, such pouches can be used for histologic monitoring of the graft.

Administration, Oral↗
PubMed1984

Functional monitors of rejection in small intestinal transplants.

Absorption of cyclosporine and uptake of radiolabelled glucose by the transplanted small intestine in the dog was investigated to develop physiologic markers of rejection. Cyclosporine in olive oil was given orally, and glucose-14C was instilled into an isolated pouch constructed from the transplanted jejunum. Biopsies were simultaneously obtained from an isolated pouch made from the transplanted ileum. The absorption data were correlated with the histologic findings. Absorption of cyclosporine was of the same magnitude in autotransplanted dogs as it was in allotransplanted dogs with a normal graft. Absorption of cyclosporine in allotransplanted dogs with histologic signs of rejection was significantly reduced. Peak uptake of glucose-14C was noted 5 to 10 minutes after instillation of the isotope in autotransplanted and allotransplanted dogs with a normal graft. Allotransplanted dogs undergoing rejection had a delayed appearance of peak uptake and significantly reduced absolute uptake. In conclusion, absorption of cyclosporine and uptake of radiolabelled glucose can be utilized as functional monitors of intestinal allograft rejection.

Animals↗
PubMed1984

Arteriovenous shunt using the sleeve technique in the dog.

Arteriovenous shunts were constructed in 12 dogs for simplified venous access. A modified end-in-end technique was used. In this technique, the donor vessel is telescoped into the recipient vessel and kept in place with two sutures, not exposed to the blood stream. Mean skin-to-skin time was 17 minutes. Ten shunts were patent one week after construction. Nine were open after one month. We have concluded that this anastomotic technique is suitable for the construction of arteriovenous shunts in dogs and that it facilitates venous access.

Animals↗