Progress in the management of retrorectal tumours

AIM

Tumours in the retrorectal space are rare and pathologically heterogeneous. The roles of imaging and preoperative biopsy, nonoperative management and the indications for surgical resection are controversial. This study investigated a series of retrorectal tumours treated in a single institution with the aim of producing a modern improved management algorithm.

METHOD

A retrospective analysis was conducted of the management of all retrorectal lesions identified between 1998 and 2013 from a radiology database search. Patient demographics, presenting symptoms, imaging, biopsy, management and the results were recorded. Descriptive statistics were used and Kaplan-Meier survival analysis was performed.

RESULTS

Sixty-nine patients with a confirmed retrorectal tumour were identified. The median age was 50 (36-67 interquartile range) and 42 (56%) were female. Twenty (29%) of the tumours were malignant: 4 of 41 cystic lesions were malignant (12.9%) vs. 16 of 28 solid (or heterogeneous) lesions (57.1%) (P < 0.0001). Imaging demonstrated a 95% sensitivity and 64% specificity for differentiating benign from malignant tumours. Magnetic resonance imaging (MRI) was significantly better at distinguishing between benign and malignant tumours than computed tomography (94% vs. 64%, P = 0.03). Percutaneous biopsy was performed in 16 patients and only 27 underwent resection. There was no evidence of local recurrence associated with biopsy. Solid lesions were associated with a nonsignificant decreased overall survival (P = 0.348).

CONCLUSION

This study demonstrated that MRI should be the investigation of choice for retrorectal lesions. Biopsy of solid lesions is safe and useful for guiding neoadjuvant and surgical therapy. Cystic lesions without suspicious radiological features can be followed by serial imaging without resection.

The low FODMAP diet improves gastrointestinal symptoms in patients with irritable bowel syndrome: a prospective study

BACKGROUND AND AIM

Current treatment for irritable bowel syndrome (IBS) is suboptimal. Fermentable oligo-, di-, mono-saccharides and polyols (FODMAPs) may trigger gastrointestinal symptoms in IBS patients. Our aim was to determine whether a low FODMAP diet improves symptoms in IBS patients.

METHODS

Irritable bowel syndrome patients, who had performed hydrogen/methane breath testing for fructose and lactose malabsorption and had received dietary advice regarding the low FODMAP diet, were included. The effect of low FODMAP diet was prospectively evaluated using a symptom questionnaire. Furthermore, questions about adherence and satisfaction with symptom improvement, dietary advice and diet were assessed.

RESULTS

Ninety patients with a mean follow up of 15.7 months were studied. Most symptoms including abdominal pain, bloating, flatulence and diarrhoea significantly improved (p < 0.001 for all). 75.6%, 37.8% and 13.3% of patients had fructose, lactose malabsorption or small intestinal bacterial overgrowth respectively. Fructose malabsorption was significantly associated with symptom improvement (abdominal pain odds ratio (OR) 7.09 [95% confidence interval (CI) 2.01-25.0], bloating OR 8.71 (95% CI 2.76-27.5), flatulence OR 7.64 (95% CI 2.53-23.0) and diarrhoea OR 3.39 (95% CI 1.17-9.78), p < 0.029 for all). Most patients (75.6%) were adherent to the diet, which was associated with symptom improvement (abdominal pain, bloating, flatulence and diarrhoea all significantly associated with adherence, r > 0.27, p < 0.011). Most patients (72.1%) were satisfied with their symptoms.

CONCLUSIONS

The low FODMAP diet shows efficacy for IBS patients. The current strategy of breath testing and dietary advice provides a good basis to understand and adhere to the diet.

The impact of splenectomy on outcome after resection for colorectal cancer: a multicenter, nested, paired cohort study

PURPOSE

This study was designed to determine whether incidental splenectomy for iatrogenic injury affects long-term cancer-specific survival in patients having resection of an adenocarcinoma of the sigmoid or rectum.

METHODS

A retrospective case-matched review of patients undergoing surgery for colorectal cancer with incidental splenectomy between January 1, 1990 and December 31, 1999 was undertaken. Data were analysed for age, American Society of Anesthesiologists physical status, gender, disease stage, operation type, and outcome. These cases were matched with patients from the same center, of the same age and gender, with the same stage of disease and operation, who did not require a splenectomy at the time of their surgery.

RESULTS

Fifty-five patients were identified who had an iatrogenic splenectomy. Matched gender, stage, and American Society of Anesthesiologists-matched controls were identified. Follow-up from time of surgery to death or last follow-up ranged from 2 to 205 (median, 43) months. A Kaplan-Meier survival analysis using the Cox proportional hazards model to define the statistical significance found a significant difference between the groups favoring those without splenectomy (hazard ratio, 1.8; 95 percent confidence interval (CI), 1-3.3; P=0.0399). Cancer-specific survival at five years was 70 vs. 47 percent and at ten years was 55 vs. 38 percent.

DISCUSSION

Patients with colorectal cancer who had splenectomy as a result of iatrogenic damage of the spleen while undergoing resection of the sigmoid or rectum for adenocarcinoma had a significantly worse prognosis.

Reasons for failure to diagnose colorectal carcinoma at colonoscopy

BACKGROUND AND STUDY AIMS

Colonoscopy can produce false-negative results, and the reasons for this remain obscure. The aim of this study was to examine why cancers are missed at colonoscopy.

PATIENTS AND METHODS

All colonoscopies carried out at Christchurch Hospital, New Zealand, over a 43-month period (1 October 1997 - 30 April 2001) were retrospectively analyzed (the data having been prospectively collected). All cases of colorectal carcinoma during the period 1 October 1997 - 30 July 2001 (3 months longer, to capture delayed diagnoses) were also identified. The two databases were then compared, and all cases in which a colonoscopy had been performed more than 6 weeks before a colorectal carcinoma specimen being received by the pathology department were identified and analyzed.

RESULTS

A total of 5055 colonoscopies were undertaken in 4598 patients. Over this period, 630 colorectal carcinomas were identified in the pathology database; 286 of the patients affected were in the colonoscopy and pathology database. Sixty-six patients had had a colonoscopy performed more than 6 weeks before the diagnosis of colorectal carcinoma. Carcinoma was identified in 48 of these 66 patients, and management was being provided. Seventeen cancers (5.9 %) were missed at colonoscopy, and the patients had had an incomplete colonoscopy in nine of these cases. In seven of the 17, an alternative benign cause was recorded. In four patients, a lesion was seen and thought to be benign, although subsequently proven not to be. In another four cases, the cancer was not diagnosed despite adequate bowel preparation and what was thought by the colonoscopist to be an adequate colonoscopy.

CONCLUSIONS

Colonoscopy missed 17 of 286 cancers (5.9 %). The reasons why cancers were missed relate to incomplete colonoscopy, poor bowel preparation, misinterpretation of what was seen, failure to carry out adequate biopsy (and follow-up) of lesions seen, and systems failures related to follow-up investigations in patients who had an incomplete colonoscopy. The fact that colonoscopy and barium enema investigations may fail to diagnose cancers has important medicolegal implications. The recognition that colonoscopy may miss a cancer should encourage doctors to reinvestigate patients when there is a lack of correlation between the clinical and investigative findings.

Penile and clitoral stimulation for faecal incontinence: external application of a bipolar electrode for patients with faecal incontinence

OBJECTIVE

The aim of this study was to assess the effect of a novel pudendal nerve stimulator on clinical and anorectal manometric parameters in patients with faecal incontinence.

METHOD

Retrospective cohort analysis of consecutive patients presenting with faecal incontinence who had failed initial conservative treatment and were not suitable for surgical intervention in a university hospital incontinence clinic. Biofeedback using a pudendal nerve stimulator comprising a bipolar electrode applied to the base of the clitoris or penis. Electrical pulse voltage was self-titrated and defined periods of treatment were prescribed. Anorectal manometry and Cleveland incontinence scores were assessed.

RESULTS

There was a significant reduction in incontinence symptom score after pudendal nerve stimulator treatment in the 42 patients treated and who had a complete set of data (median age 57 years (range 37-81); 39 female, 3 male). This was accompanied by significant improvements (P < 0.05) in anal sphincter tone, maximal tolerated rectal volume and the sustained rectoanal inhibitory reflex.

CONCLUSIONS

An externally applied pudendal nerve stimulator improves symptoms and physiological evidence of faecal incontinence but long-term follow up is not available for these patients.

The utility of laparoscopy in the diagnosis of acute appendicitis in women of reproductive age

AIM

To see whether laparoscopy improves the accuracy of a clinical diagnosis of acute appendicitis in women of reproductive age, and to determine what the long-term sequelae are of not removing an appendix deemed at laparoscopy to be normal.

METHOD

The initial part of the study was undertaken during 1991-1992. Female patients between 16 and 45 years were eligible for inclusion once a clinical decision had been made to perform an appendicectomy for suspected acute appendicitis. Following consent, patients were randomized into two groups. One group had open appendicectomy, as planned. The other group had laparoscopy, followed by open appendicectomy only if the appendix was seen to be inflamed or was not visualized. The end points for the study were the clinical outcomes of all patients, and the results of histology, where appropriate. An attempt was made to contact all patients at 10 years to determine whether they had had a subsequent appendicectomy, or had been diagnosed with another abdominal condition that might be relevant to the initial presentation in 1991-1992.

RESULTS

Laparoscopic assessment was correct in all cases in which the appendix was visualized. Diagnostic accuracy was improved from 75% to 97%. Laparoscopy was associated with no added complications, no increase in hospital stay in patients who went on to appendicectomy, and a reduction in hospital stay for those who underwent laparoscopy alone. No patients developed a problem over the 10-year follow-up period from having a normal-looking appendix not removed at laparoscopy.

CONCLUSION

Laparoscopic assessment of the appendix is reliable, and to leave a normal-looking appendix at laparoscopy does not appear to cause any long-term problems.

A retrospective audit of long-term lower limb complications following leg vein harvesting for coronary artery bypass grafting

OBJECTIVE

To evaluate the prevalence of leg complications following leg-vein harvest for coronary artery bypass grafting.

METHOD

A questionnaire was sent to patients who had coronary artery bypass surgery between January 1993 and December 1998. Questions addressed pain, numbness, infection, swelling and general healing. The relationship between the risk factors of diabetes, peripheral vascular disease, previous fractures/injuries to legs, previous deep vein clots and arthritis affecting the legs with post operative symptoms of pain, numbness, swelling and general healing was explored with multivariate analysis.

RESULTS

Of 700 questionnaires sent out 497 were returned, of which 422 (60%) were suitable for analysis. Numbness or tingling related to the wound was reported by 256 (61%), of whom 94 (37%) improved within 3 months. However, 105 (41%) had persistent numbness beyond 2 years. Pain in the wound was reported by 193 (46%), of whom 149 (77%) reported that this had improved by 3 months and only 19 (10%) had pain persisting beyond 2 years. A leg wound infection was reported by 126 (32%) patients, with 82 (65%) of these receiving antibiotics. A total of 336 (87% of 387 responses) described their wound as completely healed at 3 months. Unilateral leg swelling was reported by 175 (41%) with 98 of these (56% of those with swelling) improving by 3 months and 41 (23%) with swelling persisting beyond 2 years. There was no relation of wound problems to examined risk factors diabetes (P-values for numbness 0.31, wound healing 0.15, swelling 0.21, pain 0.22) and peripheral vascular disease (P-values for numbness 0.8, wound healing 0.21, swelling 0.18, pain 0.09). There was insufficient data to comment on the influence of fractures/injuries to legs, previous deep vein clots and arthritis affecting the legs.

CONCLUSIONS

Wound complications are common following leg vein harvest. Prevalence of infection was higher than has previously been reported. Few people suffer long-term pain from saphenous nerve damage although paraesthesia and swelling were common long-term complications. We did not identify either diabetes or peripheral vascular disease as a risk factor for pain, numbness, swelling or problems with general healing. There is a need for a large multicentre prospective study.

A multicentre retrospective audit of outcome of patients undergoing curative resection for rectal cancer

AIM

This study describes the outcome of patients with rectal cancer treated in four New Zealand public hospitals before the advent of specialised colorectal units in order to provide a baseline against which any changes in management can be measured.

METHODS

A retrospective review of case notes of patients who underwent resection of rectal cancer with curative intent over a period of 7-10 years up to 1995 in Christchurch, Wellington, Nelson, and Masterton Public Hospital's, was undertaken. Patients were identified from hospital records using a combination of methods (pathology data bases, clinical case mix data, operating logs and audit data). Metastatic disease was considered to be present if confirmed on histology or the clinical course of the patient was consistent with metastatic disease. Patients were excluded if there was perioperative evidence of metastatic disease or if they had transanal excision. Previously published results from Auckland and Dunedin Hospitals are compared.

RESULTS

524 patients with rectal cancer were identified who had undergone surgery with curative intent in the four hospitals. The overall permanent stoma rate was 37%. The overall 30-day mortality was 2.9%, five-year survival was 63% and local recurrence at five years was 26%.

CONCLUSION

While low perioperative mortality and good long-term survival were achieved, there were high rates of local recurrence. These data are a baseline against which the impact of new approaches to curative resection for rectal cancer can be measured.

Postoperative epidural analgesia following elective major abdominal surgery in high risk patients: a retrospective cohort study

AIM

To describe the effect of post-operative epidural analgesia on morbidity and mortality rates in a group of high-risk patients undergoing elective major abdominal surgery.

METHODS

Retrospective chart review of patients in American Society of Anaesthetists Physical Status (ASA) category III or IV, who underwent elective major I or II general surgical procedures between 01/01/1996 and 01/09/1998. Patients were identified from a prospective audit database. Patients who had epidural analgesia or conventional parenteral opioids were compared for outcome measures.

RESULTS

There were 167 patients identified (72 epidural, 95 non-epidural group). There was no significant difference in demographic data, inpatient stay, intensive care unit stay, or mortality rates (11% epidural v 17% non-epidural, p>0.05). There was no significant difference in morbidity rates, however there was a non-significant trend towards a lower morbidity in the epidural group.

CONCLUSIONS

This study does not show any benefit from post-operative epidural analgesia on morbidity and mortality rates in high risk patients undergoing major abdominal surgery. It does illustrate that ASA 3 and 4 patients undergoing major abdominal surgery have a high morbidity and mortality.

The prevalence of faecal incontinence and constipation in a general New Zealand population; a postal survey

AIMS

To determine the prevalence of constipation and faecal incontinence in the community.

METHODS

A 20-question multi-field postal questionnaire was sent to 1500 adults (over 18 years) randomly selected from the electoral roll in the Canterbury region. Questions detailed frequency of bowel function, time spent at the toilet, incidence and severity of faecal incontinence, constipation, and the effect of disordered bowel function.

RESULTS

Of 1500 questionnaires, 717 (48%) were returned (male: female 388:329). The median age was 46 years (range 18-70). 24 (4%) had self-reported gastrointestinal disease. There was a median frequency of seven bowel motions per week (BM/wk) (range 1 to 70) with 89% having between two motions a day and one every two days. Faecal incontinence affected lifestyle in 58 (8.1%). Incontinence of solid stool at least once a month occurred in 70 (9.8%), of liquid stool in 91 (12.7%), of gas in 459 (64%), while 12 (2%) regularly wore a pad. Those with self-reported gastrointestinal disease had a significantly higher (p<0.05) bowel motion frequency (17 vs 7 BM/wk) and median faecal incontinence score (2.5 vs 0). Laxatives were used by 4.9% of the population, while 26.2% increased fibre to avoid constipation.

CONCLUSIONS

The normal frequency of bowel motions (+/- 2SD) was 2-17 per week. Faecal incontinence affecting life style affected 8.1%, while constipation requiring regular laxative use affected 4.9% of people. There is acceptance in the community that a moderate degree of bowel dysfunction is normal. Stool frequency and faecal incontinence scores can be used to predict those most likely to have organic gastrointestinal disease.

Does anorectal manometry predict clinical outcome after laparoscopic ACE procedures in children with spina bifida?

PURPOSE

The laparoscopic antegrade continence enema (LACE) procedure is used for the treatment of faecal incontinence in children with spina bifida. The purpose of this study was to relate the outcome of the LACE procedure to anorectal function, as determined by anorectal manometry.

METHOD

Eleven children with spina bifida who had the LACE procedure underwent anorectal manometry (ARM) to document their anorectal function, and its relationship to the level of continence obtained following surgery.

RESULTS

There was a consistently high level of functional continence achieved following surgery despite wide variability in the parameters of anorectal manometry. There was no demonstrable correlation between the outcome of the LACE procedure and anorectal function as assessed by manometry.

CONCLUSION

Anorectal function as determined by manometry failed to predict outcome after the laparoscopic ACE procedure in children with spina bifida.

Does a colostomy alter quality of life in patients with spinal cord injury? A controlled study

STUDY DESIGN

Prospective controlled comparative analysis.

OBJECTIVE

To determine whether a colostomy changes quality of life in patients with a spinal cord injury.

METHOD

A previously validated questionnaire designed to assess quality of life in spinal injured patients (Burwood Questionnaire) was sent to 26 spinal cord injured patients with colostomies and 26 spinal cord injured patients without colostomy. The two groups were matched for level of injury, completeness of injury, length of time since injury, age (+/- 5 years) and gender.

RESULTS

There was 100% completion of the questionnaire. There was no significant difference (P > 0.05) in the two groups of patients in regard to their general well being, emotional, social, or work functioning.

CONCLUSIONS

Patients with colostomy following spinal injury are no worse off in regard to quality of life, than those without. The inference is that perhaps a colostomy should be considered earlier in patients with major bowel dysfunction following spinal cord injury.

SPONSORSHIP

Financial support for Dr AC Lynch was provided by Royal Australian College of Surgeons with a Foundation Scholarship and Grant in aid by the Burwood International Spinal Trust. Mr N Randell was supported by the Canterbury Medical Research Foundation with a summer studentship.

Bowel dysfunction following spinal cord injury

STUDY DESIGN

Review.

OBJECTIVES

To outline the present knowledge of bowel dysfunction following spinal injury, and look at future directions of management and research.

SETTING

Spinal Unit and Colorectal Unit, Christchurch, New Zealand.

METHODOLOGY

Review.

RESULTS

The underlying physiology of colorectal motility and defecation is reviewed, and consequences of spinal cord injury on defecation are reported. A discussion of present management techniques is undertaken and new directions in management and research are suggested.

CONCLUSION

There is need for more intervention in regard to bowel function that could improve quality of life, but there is also a need for more research in this area.

Bowel dysfunction following spinal cord injury: a description of bowel function in a spinal cord-injured population and comparison with age and gender matched controls

STUDY DESIGN

A controlled, descriptive and comparative, questionnaire based study.

OBJECTIVES

To describe the bowel function of spinal cord injured (SCI) patients and compare this with a general community control group.

SETTING

Christchurch, New Zealand.

METHODOLOGY

A postal questionnaire was sent out to past SCI patients of the Burwood Spinal Injuries Unit, Christchurch, New Zealand, and age/gender matched with controls randomly selected from the electoral roll. Permission was obtained from SCI participants to retrieve data relating to their injury from hospital case notes. The questionnaire detailed general bowel function, influence of bowel problems on everyday life, incidence of incontinence and methods of defecation. A Faecal Incontinence Score was generated according to an established incontinence grading scheme.

RESULTS

Questionnaires were sent out to 1200 SCI patients and 1200 control subjects. Of these, 467 completed questionnaires were returned from SCI patients and age/gender matched from the 668 returned control questionnaires. Mean Faecal Incontinence Score was higher for SCI patients than controls (P<0.0001), and for complete compared with incomplete injury (P=0.0023). Age or time from injury did not affect Faecal Incontinence Score. Incontinence affected quality of life for 62% of SCI patients, compared with 8% of controls. Faecal urgency and time spent at the toilet were also significantly higher for the SCI group (39% of SCI patients use laxatives, compared with 4% of controls (P<0.0001)). Haemorrhoidectomy was more common (P<0.001) in the SCI population (9% vs 1.5%), particularly among those requiring manual evacuations.

CONCLUSION

SCI has a significant effect on bowel function in terms of faecal incontinence, urgency, and toileting methods. This results in a marked impact on quality of life. While bowel function may deteriorate with time, most patients with poor function can be identified early implying a role for early intervention in those with potential bowel problems, such as colostomy or ACE procedure.

Comparison of micronutrients in patients having had panproctocolectomy and either ileal pouch anal anastomosis or Brooke ileostomy for chronic ulcerative colitis (UC)

OBJECTIVE

Patients having panproctocolectomy undergo major metabolic changes. A recent study suggested that patients who have had a panproctocolectomy and ileal pouch-anal anastomosis (IPAA) may be trace element-deficient, while other recent evidence has suggested a gradual decrease in vitamin B12. This study was undertaken to compare patients who had a panproctocolectomy for UC in combination with either an IPAA or a Brooke ileostomy (BI), and to determine whether the type of surgery post-proctocolectomy influences the absorption of trace elements, as well as comparing the levels after both operations with the normal population values.

PATIENTS AND METHODS

One hundred randomly selected patients who had had a panproctocolectomy for UC (50 IPAA, 50 BI) were invited to take part in the study by letter. The patients who consented had blood taken for haemoglobin, serum iron, ferritin, serum folate, red cell folate, vitamin B12, insulin-like growth factor-1 (IGF-1), albumin, and the trace elements copper, magnesium, manganese, selenium, and zinc.

RESULTS

Of the 100 patients, 46 consented to participate in the study (23 IPAA, 23 BI). The age of the BI group was significantly higher than those of the IPAA group (mean age IPAA 44 years, BI 52 years, P < 0.05). There was no significant difference between the two groups with respect to time since operation, mean levels of haemoglobin, iron indices, albumin, serum and red cell folate, vitamin B12, or any of the trace elements examined. Plasma IGF-1 was higher in the IPAA group, but this was no longer significant when adjusted for age.

CONCLUSION

No difference was found in trace element status in patients who had had a panproctocolectomy for UC with either an IPAA or BI. Furthermore, no difference existed between these two groups.

Anorectal physiology following spinal cord injury

PURPOSE

Spinal cord injured (SCI) patients have delayed colonic motility and anorectal dysfunction resulting in functional obstruction and constipation. This may be caused by changes in descending modulation from the central or sympathetic nervous systems. Anorectal dyssynergy may demonstrate similarities to that seen in the bladder following SCI.

METHODOLOGY

Anorectal manometry was performed on 37 SCI volunteers. Patterns of rectal and sphincter function were identified. These patterns were then compared with questionnaire answers on bowel function and cystometrograms to identify a relationship between detrusor dyssynergy and anal sphincter tone.

RESULTS

Rectal compliance and basal resting sphincter pressures were lower than normal values. Ramp rectal inflation demonstrated patterns of sphincter activity similar to that recorded in the patients' cystometrograms. There is no definite relationship of bowel function to the findings on manometry in SCI patients.

CONCLUSIONS

SCI patients have abnormal anorectal function. Anorectal manometry results were able to be classified into four patterns on the basis of rectal pressure and sphincter tone in response to rectal distention. The patterns of anorectal manometry seen were similar to those in cystometrograms, however there is no definite relationship to bowel dysfunction. Spinal Cord (2000) 38, 573 - 580.

Pancreatic cancer and diabetes: is there a relationship? A case-controlled study

BACKGROUND

There is controversy about whether diabetes mellitus is a risk factor for pancreatic cancer or an epiphenomenon of the cancer. The present study aims to determine if long-term diabetes is a risk factor for pancreatic cancer.

METHODS

The study undertook to determine the prevalence of diabetes among three matched (age/gender) patient groups (pancreatic cancer (PaC), colorectal cancer (CRC), and fracture neck of femur (NOF)) at the date of diagnosis of cancer or fracture as well as 1 and 5 years prior to this. A retrospective review of the medical records of the three groups of patients was undertaken. Patients identified with PaC in the period July 1994 to February 1998 were age (+/- 5 years)- and gender-matched to patients identified in the same time period with NOF and with CRC. The data were then analysed using McNemar's test for discordant pairs.

RESULTS

Over a 44-month period 116 patients with PaC were identified of which 24% had diabetes at the time of diagnosis of their malignancy (NOF, 8%; CRC, 9.5%). There was a statistically significant difference (PaC and NOF, P < 0.01; PaC and CRC, P < 0.01). For a duration of diabetes of > 5 years the prevalence of diabetes fell to 7.8% in the PaC group, to 6% in the NOF group and to 6.9% in the CRC group, with no significant difference between the groups.

CONCLUSION

There is no increase in the prevalence of long-standing diabetes mellitus in patients with PaC compared to age- and gender-matched controls with NOF and CRC. The relationship of PaC and diabetes may be an epiphenomenon, rather than diabetes being a risk factor for pancreatic malignancy.

Use of (99m)Tc-DISIDA biliary scanning with morphine provocation for the detection of elevated sphincter of Oddi basal pressure

BACKGROUND

Endoscopic biliary manometry is useful in the assessment of patients with types II and III sphincter of Oddi dysfunction, but it is time consuming and invasive.

AIM

To investigate the role of (99m)Tc-DISIDA scanning, with and without morphine provocation, as a non-invasive investigation in these patients compared with endoscopic biliary manometry.

SUBJECTS AND METHODS

A total of 34 patients with a clinical diagnosis of type II (n = 21) or III (n = 13) sphincter of Oddi dysfunction were studied. Biliary scintigraphy with 100 MBq of (99m)Tc-DISIDA was carried out with and without morphine provocation (0.04 mg/kg intravenously) and time/activity curves were compared with the results of subsequent endoscopic biliary manometry.

RESULTS

Eighteen (nine type II, nine type III) of the 34 (53%) patients had sphincter of Oddi basal pressures above the upper limit of normal (40 mm Hg). In the standard DISIDA scan without morphine, no significant differences were observed in time to maximal activity (Tmax) or percentage excretion at 45 or 60 minutes between those with normal and those with abnormal biliary manometry. However, following morphine provocation, median percentage excretion at 60 minutes was 4.9% in those with abnormal manometry and 28.2% in the normal manometry group (p = 0.002). Using a cut off value of 15% excretion at 60 minutes, the sensitivity for detecting elevated sphincter of Oddi basal pressure by the morphine augmented DISIDA scan was 83% and specificity was 81%. Also, 14 of the 18 patients with abnormal manometry complained of biliary-type pain after morphine infusion compared with only two of 16 patients in the normal manometry group (p = 0.001).

CONCLUSIONS

(99m)Tc-DISIDA with morphine provocation is a useful non-invasive investigation for types II and III sphincter of Oddi dysfunction to detect those with elevated sphincter basal pressures who may respond to endoscopic sphincterotomy.

Risk factors for post-appendicectomy intra-abdominal abscess

BACKGROUND

Appendicectomy is a common emergency operation, after which major complications are uncommon, however when they do occur they are a major cause of concern to patient and surgeon. This study aims to determine the incidence and risk factors for post-appendicectomy intra-abdominal abscess formation.

METHOD

A retrospective review was undertaken of all appendicectomies undertaken in Christchurch Hospital between 1 January and 31 December 1995. Appendicectomies were identified from a database of histology. The patients' notes were reviewed and the surgical approach, histological diagnosis and postoperative complications identified.

RESULTS

A total of 417 appendicectomies was identified of which 331 were open, 66 laparoscopic, and 20 undertaken at laparotomy. Mean day stays for each group were 4.4, 4.2 and 11.5 days, respectively. The percentages of patients with acute appendicitis in each group were 87, 58 and 35%. Histologically the appendix was inflamed in 80% (334) of patients (acute 232, chronic 15, perforated 56 and gangrenous 24). There were six postoperative intra-abdominal abscesses (1.4%), all occurring in the open appendicectomy group when the histology was either perforated or gangrenous appendicitis (P < 0.001). There were no cases of postoperative abscess formation following laparoscopic appendicectomy. All cases of postoperative intra-abdominal abscess were associated with perforated and/or gangrenous appendicitis (P < 0.001). The incidence of intra-abdominal abscesses was 7.5% with a perforated and/or gangrenous appendix. There were two cases of iatrogenic perforation following laparoscopic appendicectomy.

CONCLUSION

The incidence of intra-abdominal abscess is 1.4% of all appendicectomies. The only identified risk factor for development of post-appendicectomy intra-abdominal abscess was the underlying pathology of gangrenous or perforated appendicitis.

Informed consent: what do patients want to know?

AIM

To determine which aspects of informed consent are important to patients and surgeons and to determine where there is disparity and similarity.

METHOD

A questionnaire was developed from the Disability Commissioner's Regulations (1996) and was administered to 256 patients and 37 doctors at Christchurch Hospital.

RESULTS

According to patients the five most important aspects of informed consent were: (1) the major risks, (2) quality of life, (3) outcome, (4) consequences of not undergoing the procedure and (5) quantity of life. The five most important aspects to the doctors were (1) the general nature of the procedure, (2) major risks, (3) consequences of not undergoing the procedure, (4) alternative options and (5) consequences of the procedure in regard to management. The aspects of informed consent of greatest divergence (power of divergence, p < 0.05) between patient and doctor were (1) the importance of technical details of the procedure, (2) cost to the country, (3) qualifications of the doctor, (4) experimental and non-conventional treatment options and (5) whether the doctor would have the procedure if they were in the position of the patient.

CONCLUSIONS

This study has identified aspects of informed consent that patients and doctors consider important, as well as aspects where there are significant differences. Both patients and doctors consider the explanations of risks and complications important, especially if the complication is serious and risk is greater than 1 in 1000. Patients consider aspects of outcome (quantity and quality of life) important, while doctors are concerned about "process" including the general nature of the procedure and consequences of the procedure for the patient's management. This study gives direction to medical practitioners concerning what it is that patient's are wanting to know during informed consent about a procedure.

Lipoproteins and the liver sieve: the role of the fenestrated sinusoidal endothelium in lipoprotein metabolism, atherosclerosis, and cirrhosis

The liver sieve, formed by the fenestrated hepatic sinusoidal endothelium, is a dynamic biofilter separating the hepatic blood from the plasma within the space of Disse. It filters macromolecules of differing sizes, especially lipoproteins. More specifically, it acts as a barrier to the large triglyceride-rich parent chylomicrons, while permitting the smaller triglyceride-depleted but cholesterol- and retinol-rich remnants to enter the space of Disse. There the remnants contact specific receptor sites on the hepatocyte microvilli. Thus, the liver sieve is the first site of hepatic selection and consequent metabolism of dietary cholesterol and fat-soluble vitamins, as well as rejection of dietary triglycerides. Therefore, perturbations of the porosity of the sieve, whether from changes in size, number of fenestrae, or composition of the underlying extracellular matrix within the space of Disse, will have a profound influence on the metabolism of lipoproteins. This disturbance of the homeostasis of lipids, including fat-soluble vitamins and cholesterol, as well as other macromolecules, may tilt the balance between health and disease in a variety of organs and tissues, such as the liver, kidney and arteries.

Endotoxin-induced defenestration of the hepatic sinusoidal endothelium: a factor in the pathogenesis of cirrhosis?

Defenestration and capillarisation of the hepatic sinusoidal endothelium occurs early in the pathogenesis of cirrhosis, both in patients suffering from alcohol abuse and in animal models. It is possible also that alcohol abuse promotes the absorption of bacterial endotoxins from the gastrointestinal tract. In this study we have investigated the effects of a single intravenous injection of endotoxin on the hepatic sinusoidal endothelium of rats. Seven days after the dose of endotoxin, the porosity of the sinusoidal endothelium was reduced to 40% of that of controls, due to a decrease in both diameter and number of fenestrae. The livers examined 14 days after dosing exhibited normal porosity. We postulate that bacterial endotoxins play a role in the pathogenesis of cirrhosis by modulating the fenestrated sinusoidal endothelium (liver sieve).

The fate of ingested 14C-urea in the urea breath test for Helicobacter pylori infection

The metabolic fate of the radioactive carbon in the 14C-urea breath test for Helicobacter pylori was investigated in 18 subjects. After ingestion of labelled urea, breath was sampled for 24 h, and urine was collected for 3 days. Subjects were designated high or low expirers on the basis of their breath counts, and this agreed well with H. pylori serologic analyses. When given 185 or 37 kBq of 14C-urea, 51% (SD = 16%, n = 11) of the label was recovered from the breath of high expirers, and 7% (SD = 3%, n = 7) from the breath of low expirers. The mean combined urinary and breath recovery for high expirers was 86% (SD = 7%), and for low expirers it was 97% (SD = 3%). It is concluded that the long-term retention of 14C from ingested 14C-urea is low. The results enable a more accurate estimation to be made of radiation exposure resulting from the 14C-urea breath test.

Decreased hepatic uptake of cholesterol and retinol in the dimethylnitrosamine rat model of cirrhosis

The fenestrated endothelium of the liver sinusoids forms a sieve between the circulation and hepatocytes. Fenestrae selectively permit the entrance of relatively small chylomicron remnants into the space of Disse to contact hepatocyte receptors, but obstruct the passage of the larger parent chylomicrons. Much of dietary cholesterol and most of retinol are transported as esters in the core of chylomicrons. In the dimethyl nitrosamine rat model of cirrhosis, we have described a rapid reduction in size and number of fenestrae well before the onset of cirrhosis. Concurrent with this decreased porosity is a decreased trapping of radio-labelled dietary cholesterol and retinol by these livers. We postulate that the less porous "liver sieve" hinders the hepatic uptake of chylomicron remnants, with consequent disturbance of cholesterol and retinol metabolism.

Structural and functional changes of the gastric mucosa in rats with portal hypertension

Structural and functional changes of the gastric mucosa were studied in rats made portal hypertensive by partially ligating the portal vein. Studies were carried out at either 3 or 12 days after ligation or sham operation. At 3 days, structural changes were greater than at 12 days, the major effects being vascular congestion in the lamina propria, muscularis mucosa, submucosa, and submucosal oedema. Transmission electron microscopy showed only a mild hyperplasia in the muscularis mucosa. Gastric blood flow appeared to decrease at 3 days post-ligation compared to sham-operated control rats, but was significantly increased by 12 days after ligation (P less than 0.01). Cardiac output also appeared to increase in the portal hypertensive rats by 12 days post-ligation but this was not statistically significant. Portal venous inflow was significantly increased by 12 days (P less than 0.05) but after correction for collateral circulation liver blood flow had returned to normal values by 12 days post-ligation.

Intravenous enoxacin for the treatment of acute pyelonephritis: pharmacokinetic and clinical study

1. Eight women with acute pyelonephritis were treated with i.v. enoxacin for 5 days. All were clinically cured and five had a bacteriological cure. Five women reported side effects. 2. During treatment there was no significant accumulation of enoxacin and the total clearance of the drug did not alter with repeated dosing. Drug elimination half-life (mean 4.3 h, s.d. 2.1) was similar to that reported in healthy volunteers. 3. Enoxacin should be compared with the aminoglycosides and beta-lactam antibiotics for the treatment of severe or complicated urinary tract infections.

Pharmacokinetics and sputum penetration of enoxacin after twice daily oral dosing for seven days

The ability of enoxacin to penetrate into sputum and its distribution and elimination characteristics after dosing to steady state were determined in six subjects with permanent tracheostomies. At steady state the mean trough level of enoxacin in sputum was 1.75 +/- 0.70 mg/kg (mean +/- S.D.), and the corresponding level in plasma was 1.23 +/- 0.32 mg/l. The mean peak sputum concentration at steady state was 7.12 +/- 4.21 mg/kg with the corresponding level in plasma being 4.54 +/- 1.34 mg/l. The ratio of the mean trough concentration of enoxacin in sputum to that in plasma was 1.42 +/- 0.36, and the ratio of the mean peak concentrations was 1.67 +/- 1.07. The pharmacokinetics of enoxacin in sputum were similar to those in plasma, the only significant difference being between the mean times to reach peak concentration (T-max) which were 2.62 +/- 1.04 and 0.92 +/- 0.44 h in sputum and plasma respectively (P less than 0.01). After reaching steady state, the mean area under the plasma time-concentration curve (AUC) from 0 to 12 h (the dosing interval) was 26.6 +/- 5.9 mg/h/l, and the mean AUC (0-12) for sputum was 40.9 +/- 21.8 mg/h/kg. The mean apparent total clearance was 259.6 +/- 48.8 ml/min and the mean apparent volume of distribution was 169.6 +/- 30.51. Enoxacin exhibits a high degree of penetration into sputum which may prove useful in the treatment of bacterial infections of the respiratory tract.

The effect of age on the pharmacokinetics of enoxacin

We have studied the pharmacokinetics of enoxacin in two groups of subjects, 10 young (18-45 years) and 10 elderly adults (greater than 65 years) after a single oral dose of enoxacin (600 mg). Enoxacin was absorbed rapidly, peak plasma concentrations being reached within two hours in both groups. However, the peak plasma concentration of enoxacin was significantly higher in the elderly than in the young adults. The area under the concentration-time curve extrapolated to infinity was also significantly greater in the elderly compared with the young subjects, and the apparent renal clearance was significantly less in the elderly than in the young adults. Consequently, the urinary elimination of unchanged enoxacin was significantly reduced in the elderly. The apparent volume of distribution in the elderly was significantly less than in the young adults. The elimination half-time of enoxacin was similar in the two groups.

Nonlinear pharmacokinetic characteristics of 5-fluorouracil (5-FU) in colorectal cancer patients

The nonlinear disposition kinetics of 5-fluorouracil (5-FU) were investigated in 6 patients with colorectal carcinoma. Each patient randomly received two single, intravenous doses of 5-FU (7.5 and 15 mg/kg) on separate days. Venous blood and urine samples were collected just prior to and for 5 h after drug administration. In addition to the kinetic studies, the in vitro whole blood/plasma concentration ratio and stability of 5-FU at 37 degrees C were determined in whole blood from normal volunteers and from 5 patients with colorectal carcinoma. A disproportionate increase in area under the curve and corresponding decrease in total body clearance with increasing dose was observed suggesting dose-dependent behavior of 5-FU. Doubling the dose was accompanied by a 36% decrease in nonrenal clearance but no apparent change in renal clearance. Therefore, the mechanism for dose-dependent elimination appears to be primarily associated with nonrenal processes. The mean 5-FU half-life following the high dose was nearly twice as long as that observed for the low dose (12.3 versus 6.2 min). The log-linear decline in plasma concentrations and increase in half-life with dose suggest the potential role of product-inhibition as an explanation for the observed nonlinearity in 5-FU elimination. The present study demonstrates that 5-FU degrades when incubated in whole blood. This most likely reflects metabolism in red blood cells or other blood-formed elements since 5-FU was stable in plasma. Although degradation in whole blood occurs, the estimated whole blood clearance does not contribute significantly to the observed total body clearance value. The findings suggest the possibility of pulmonary clearance of 5-FU.

Glucuronidation and elimination of diflunisal in the isolated perfused rat liver: effect of pretreatment with phenobarbitone, clofibric acid and spironolactone

The effects of pretreatment of rats with phenobarbitone, clofibric acid and spironolactone on the metabolism and biliary excretion of the salicylate derivative diflunisal have been studied using the isolated perfused liver. The clearance of diflunisal was increased significantly by pretreatment with each of the drugs. Biliary excretion of diflunisal acyl and phenolic glucuronides followed apparent first-order and Michaelis-Menten kinetics, respectively. Pretreatment with clofibric acid or spironolactone resulted in a significant increase in the biliary excretion of the phenolic glucuronide. Pretreatment with phenobarbitone or spironolactone enhanced biliary excretion of the acyl glucuronide, particularly during the first 2 hr. The concentration of the phenolic glucuronide in the perfusate increased steadily during the 6 hr perfusions, whereas the acyl glucuronide concentration was relatively stable, reflecting the ease of hydrolysis of acyl glucuronides under physiological conditions.

Isolated liver perfusion: the choice of anaesthetic

Perfused livers isolated from rats under halothane anaesthesia produced greater amounts of bile, released smaller amounts of aspartate aminotransferase, and had a much greater ability to maintain a constant concentration of glucose in perfusates than those obtained with ether or pentobarbitone. Little or no effect was shown on the ability of the liver to synthesize urea and to retain potassium within the organ. It appears, therefore,that halothane is the anaesthetic of choice when removing the liver from the laboratory rat.