Functional Constipation in Older Adults: Prevalence, Clinical Symptoms and Subtypes, Association with Frailty, and Impact on Quality of Life

INTRODUCTION

Functional constipation (FC) is very prevalent in older adults, especially in women, but its relationship with frailty is not fully understood. The aims were to assess FC prevalence, clinical symptoms and subtypes, association with frailty, and impact on quality of life (QoL) in older people.

METHODS

This epidemiological study included 384 individuals aged over 70 years recruited from the community, a hospital, and a nursing home and stratified into robust, pre-frail, and frail groups (Fried criteria). The following criteria were evaluated: frailty, FC (Rome III criteria), stool consistency (Bristol Stool Chart), comorbidities (Charlson), dependency (Barthel), QoL (EQ5D), and clinical and sociodemographic data. Defined by symptom aggregation were 2 main clinical subtypes as follows: slow colonic transit time (CTT) and functional defecation disorder (FDD).

RESULTS

Mean age was 79.11 ± 6.43 years. Overall FC prevalence was 26.8%, higher in women (32.4% women vs. 21.8% men; p = 0.019) and highest in frail patients (41.7% frail vs. 33.9% pre-frail vs. 24.2% robust; p < 0.001). Straining and hard stools (Bristol 1-2) were the most prevalent symptoms (89.3 and 75.7%, respectively). Frailty and benzodiazepine intake were independently associated with FC. Patients with FC obtained poorer QoL scores in the EQ5D (perceived health 66.09 ± 17.8 FC patients vs. 56.4 ± 19.03 non-FC patients; p < 0.05). The FDD subtype became significantly more prevalent as frailty increased (6.5, 25.8, and 67.7% for robust, pre-frail, and frail patients, respectively); the slow CTT subtype was significantly more frequent in robust patients (38.5% robust vs. 30.5% pre-frail vs. 23.1% frail), p = 0.002.

DISCUSSION/CONCLUSION

FC prevalence in older adults was high, especially in women, and was associated with frailty and poor QoL. Clinical subtypes as related to frailty phenotypes reflect specific pathophysiological aspects and should lead to more specific diagnoses and improved treatment.

A European snapshot of psychosocial characteristics and patients' perspectives of faecal incontinence-do they correlate with current scoring systems?

PURPOSE

To compare the current clinical scoring systems used to quantify the severity of symptoms of faecal incontinence (FI) to patients' subjective scoring of parameters of psychosocial well-being.

METHODS

Patients referred to six European centres for investigation or treatment of symptoms of FI between June 2017 and September 2019 completed a questionnaire that captured patient demographics, incontinence symptoms using St. Mark's Incontinence score (SMIS) and ICIQ-B, psychological well-being (HADS, Hospital Anxiety and Depression Scale), and social interaction (a three-item loneliness scale).

RESULTS

Three hundred eighteen patients completed questionnaires (62 men, mean age 58.7). Sixty percent of the respondents were aged under 65. Median SMIS was 15 (11-18), ICIQ-B bowel pattern was 8 (6-11) and bowel control was 17 (13-22), similar across all demographic groups; however, younger patients were more likely to experience symptoms of depression and anxiety (HADS score > 10, 65.2% of patients age < 65 vs 54.9% of those ages > = 65, p = 0.03) with lower quality of life (ICIQ-B QoL, median score 19 (14-23)) vs age > = 65 (16 (11-21) (p < 0.005)). On loneliness score 25.5% reported often feeling isolated from others. One of the most significant concerns by patients was the fear and embarrassment related to unpredictable episodes of incontinence.

CONCLUSION

The SMIS remains a useful tool for quantifying incontinence symptoms but may underestimate the psychosocial morbidity associated with unpredictable episodes of incontinence. Interventions aimed at decreasing anxiety and to address feelings of disgust may be helpful for a significant number of patients requiring treatment for FI.

Ingested Foreign Bodies: Do We Need a Specific Approach When Treating Inmates?

The management of foreign bodies in the gastrointestinal tract is not standardized. Foreign body ingestions in prisoners are always intentional and inmates can be manipulative, which makes medical decision even more difficult. Our objective is to propose a decisional algorithm for management of foreign body ingestion in prisoners. We reviewed the records of 198 admissions for foreign body ingestion for a 10-year period. Type and number of ingested foreign bodies, radiographic findings, outcome as well as the management method including conservative, endoscopic removal, or surgical treatment were analyzed. Most cases were managed conservatively (87.6%). Endoscopy of the upper gastrointestinal tract was performed in 37 cases with a success rate of 46 per cent. In 9.3 per cent of cases, the final treatment was endoscopic. Only five patients required surgical treatment, being emergent just in one case. We advocate conservative treatment for asymptomatic patients with foreign body ingestion. Endoscopic removal is proposed for pointed objects or objects bigger than 2.5 cm located in the stomach. Objects longer than 6 to 8 cm located in the stomach should be removed by endoscopy or laparoscopy. Patients with objects in the small bowel or colon should be treated conservatively unless there are complications or they fail to progress.

Bowel dysfunction in survivors of gynaecologic malignancies

PURPOSE

To assess the prevalence of bowel dysfunctions after treatment for gynaecological cancer and the impact on the quality of life.

METHODS

We identified a cohort of 217 eligible women treated with radiotherapy (RT) with curative intention, alone or as combined treatment, for gynaecological malignancies at three institutions in Catalonia (Spain). Demographic, diagnosis and treatment modality were reviewed. Patients were sent validated questionnaires to assess bowel function and a set of questions asking on the changes after RT in bowel function, urinary function, sexuality, pain and lymphoedema.

RESULTS

Questionnaires were returned by 109 patients (50.2%) with a mean age of 65 ± 11 years. Of them, 71.8% had been treated for endometrial cancer and 28.2% for cervical cancer. Overall, 42.7% of patients reported bowel dysfunction, affecting their quality of life in 36% of cases. Symptoms were more frequent in patients who had undergone external beam RT compared to brachytherapy. The most common symptom was defecatory urgency which was reported by more than 40% of patients according to the St Mark's score, although it was less common in other questionnaires. Overall, faecal incontinence ranged between 10 and 15%, and usual loose stools and diarrhoea were reported by 13.5% and 5.1%, respectively.

CONCLUSION

Prevalence of bowel symptoms after treatment of gynaecological malignancies is high. A systematic evaluation using validated questionnaires should be performed in order to allow the decision-making process and also because there are a number of treatments available to improve the quality of life of cancer survivors.

Assessment of acute bowel function after radiotherapy for prostate cancer: Is it accurate enough?

BACKGROUND AND PURPOSE

Pelvic radiotherapy for prostate cancer can be associated with bowel toxicity, which may have a significant impact on quality of life. Our aim was to assess the adequacy of the tools currently used to assess bowel symptoms after radiotherapy, including physician and patient reported outcomes. This sub-study on acute toxicity was part of a prospective trial assessing long-term bowel dysfunction.

MATERIALS AND METHODS

Between February 2013 and July 2015, 75 patients with prostate cancer who received radiotherapy completed the LENT/SOMA and the EPIC questionnaires baseline and 2 weeks after the treatment. The Bristol stool scale and two additional questions on faecal urgency were added. Physicians assessed toxicity using Common Terminology Criteria for Adverse Events v.4.0. Agreement between patients and clinicians was assessed using the Cohen's κ coefficient.

RESULTS

Acute toxicity during radiotherapy was very low. The pattern of overall bowel bother was similar before and after treatment. Faecal urgency significantly increased after radiotherapy compared to baseline but was only detected by the additional questions and not by the physicians or the patient-reported outcomes (PRO) questionnaires. Correlation between physician and PRO was poor for most symptoms.

CONCLUSION

Bowel symptoms such as urgency may remain undetected by usual tools to assess toxicity after radiotherapy. Assessment of bowel toxicity should be reappraised in order to identify those patients who may have symptoms with an impact on their quality of life.

Short-term outcome of percutaneous tibial nerve stimulation for low anterior resection syndrome: results of a pilot study

AIM

Percutaneous tibial nerve stimulation (PTNS) is a minimally invasive procedure which has been demonstrated to be effective in faecal/urinary incontinence but has never been tested in low anterior resection syndrome (LARS). The severity of LARS may be evaluated by the LARS score, but rectal cancer treatments may also affect urinary and sexual function, which are not explored by the LARS score. The Three Axial Perineal Evaluation (TAPE) score is a new validated index addressing the overall pelvic floor functions. This study aims to assess the efficacy of PTNS in LARS patients and to evaluate the results by the LARS and TAPE scores.

METHODS

Twenty-one patients operated on for rectal cancer between 2009 and 2014 complaining of LARS underwent PTNS (12 sessions of 30 min each). Six patients reported urinary incontinence and all except two (men) were sexually inactive. The LARS score and the TAPE score questionnaires were administered at baseline and after 6 months of follow-up.

RESULTS

At 6 months' follow-up, nine patients reported a significant improvement of faecal incontinence and 3/6 an improvement of urinary incontinence after PTNS. Median LARS score significantly decreased from 32 to 27 (P = 0.009), while the median TAPE score improved significantly from 55 to 58 (P = 0.004).

CONCLUSIONS

PTNS may be a further option in the treatment of selected patients with LARS and in addition may improve associated urinary incontinence. The severity of LARS can be detected by the LARS score; however, the adoption of the TAPE score is preferred in the case of concomitant urinary and/or sexual problems not explored by the LARS score.

Initiative to improve detection of faecal incontinence in primary care: The GIFT Project

BACKGROUND

Faecal incontinence (FI) is a distressing condition with a significant impact on quality of life. The true prevalence of FI is unknown but probably underestimated. Identifying patients affected is of key importance because a significant proportion may improve with conservative treatments, and there are a number of other treatments available.

OBJECTIVES

The aim of our project was to improve detection of FI in our primary care setting.

METHODS

A multidisciplinary working group was created in order to raise awareness and educate health professionals about FI. We designed a simple protocol and organized educational meetings at 7 primary care centres. The usual diagnostic computer-based tools used by nurses were modified, so that FI was systematically asked about. A proactive attitude among doctors and midwives regarding FI was recommended for high-risk patient groups.

RESULTS

The project was implemented in October 2014. Before the intervention, only 250 (<1%) patients with a diagnosis of FI were identified from the primary care register out of a population over 165000 people. Between October 2014 and February 2016, 17370 patients were questioned about anal continence in routine follow-ups. Of those questioned, 829 (4.8%) disclosed suffering from FI. Mean age was 78.5 ± 14 years (16-104), 565 (68.2%) were females, and 264 (31.8%) were males. The percentage of patients with FI increased with age and was higher in women.

CONCLUSION

Our results show that a proactive approach with direct questions on FI may lead to a significant increase in FI detection in primary care.

Clinical application of the LARS score: results from a pilot study

PURPOSE

The impact of the low anterior resection syndrome (LARS) on quality of life has underscored the importance of measuring functional outcomes after treatment for rectal cancer. The aim of this study was to evaluate whether the LARS score as a single questionnaire was useful enough in the clinical setting.

METHODS

Patients treated by curative anterior resection for rectal cancer were sent the LARS score and the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 questionnaires by post. Patients classified as "minor" and "major" LARS according to the LARS score were visited. Assessment included several scores (Vaizey score, Altomare Obstructed Defecation Syndrome score, Bristol scale). Patients with urgency/faecal incontinence also filled in a bowel diary and the FIQL score.

RESULTS

Seventy patients returned the questionnaires, 49 of whom ("major LARS" and "minor LARS") were visited and 19 ("no LARS") were assessed by phone. Four different clinical patterns were identified. The group with urgency/faecal incontinence was the largest (33.8 %), whereas 17.7 % referred evacuatory dysfunction. The LARS score did not correctly evaluate 18 patients: 5 who were classified as no LARS but had severe evacuatory dysfunction and 13 patients categorized as LARS but without significant bowel dysfunction, 9 of whom were classified as major LARS.

CONCLUSION

The LARS score may overestimate the impact on quality of life in some patients and may underestimate the impact of severe evacuatory dysfunction. Due to the complexity of the LARS, the LARS score as a single questionnaire might not be enough to assess bowel function. A complete clinical evaluation and additional questionnaires might be required.

The influence of obesity and body mass index on the outcome of laparoscopic colorectal surgery: a systematic literature review

AIM

The relationship between obesity, body mass index (BMI) and laparoscopic colorectal resection is unclear. Our object was to assess systematically the available evidence to establish the influence of obesity and BMI on the outcome of laparoscopic colorectal resection.

METHOD

A search of PubMed/Medline databases was performed in May 2015 to identify all studies investigating the impact of BMI and obesity on elective laparoscopic colorectal resection performed for benign or malignant bowel disease. Clinical end-points examined included operation time, conversion rate to open surgery, postoperative complications including anastomotic leakage, length of hospital stay, readmission rate, reoperation rate and mortality. For patients who underwent an operation for cancer, the harvested number of lymph nodes and long-term oncological data were also examined.

RESULTS

Forty-five studies were analysed, the majority of which were level IV with only four level III (Oxford Centre for Evidence-based Medicine 2011) case-controlled studies. Thirty comparative studies containing 23 649 patients including 17 895 non-obese and 5754 obese showed no significant differences between the two groups with respect to intra-operative blood loss, overall postoperative morbidity, anastomotic leakage, reoperation rate, mortality and the number of retrieved lymph nodes in patients operated on for malignancy. Most studies, including 15 non-comparative studies, reported a longer operation time in patients who underwent a laparoscopic procedure with the BMI being an independent predictor in multivariate analyses for the operation time.

CONCLUSION

Laparoscopic colorectal resection is safe and technically and oncologically feasible in obese patients. These results, however, may vary outside of high volume centres of expertise.

A systematic literature review on the use of vacuum assisted closure for enterocutaneous fistula

AIM

Enterocutaneous fistula (ECF) is considered to be one of the most challenging complications a general surgeon can encounter. The current mainstay of treatment is surgical closure, associated with significant morbidity and mortality. Vacuum assisted closure (VAC) has been successfully used for closure of persistent abdominal wounds for a number of years. This study aims to investigate whether current literature supports the use of VAC for ECF.

METHOD

A PubMed search of the search terms 'enterocutaneous fistula' and 'vacuum assisted closure/therapy' was performed in December 2014. Results were restricted to articles involving human subjects with an available abstract and full text written between 1950 and 2014. The end-points analysed included rate of fistula closure, duration of follow-up, and morbidity and mortality where available.

RESULTS

Ten studies (all level IV) including 151 patients were examined. In all except one, surgery was the underlying aetiology with median number of fistulae per patient of one. The median rate of closure with VAC was 64.6% (7.7-100%) with healing occurring within 58 (12-90) days. Follow-up was only mentioned in three of the 10 studies, in which the patients were followed for 3, 20 and 28.5 months. No complications were reported in all but one of the studies, in which abdominal wall disruption and intestinal obstruction were identified in a minority of patients.

CONCLUSION

The included studies suggest that VAC therapy may be considered a safe treatment for ECF. The current evidence is generally of low level and characterized by heterogeneity. Definitive recommendations based on this information cannot therefore be made. Further studies are necessary to establish any proven benefit over standard surgical or conservative therapy.

Quality of Life Differences in Female and Male Patients with Fecal Incontinence

Background/Aims

To explore and compare quality of life (QoL) differences in female and male patients with fecal incontinence.

Methods

Ninety-one patients with fecal incontinence (60 women, mean (SD) age 64.13 (9.72) years; 31 men, mean (SD) age 63.61 (13.33) years) were assessed for pathophysiology (anorectal manometry and ultrasound), clinical severity (Wexner and Vaizey scales), QoL (Fecal Incontinence Quality of Life Score [FIQL]) and health status (EQ-5D).

Results

External and internal anal sphincter impairment rates were 96.5% and 70.2%, respectively, in women, compared to 30% and 43.3% respectively in men (P < 0.05). Clinical severity was similar in both sexes, with mean (SD) Wexner scores of 10.95 (4.35) for women and 9.81 (4.30) for men, and mean (SD) Vaizey scores of 13.27 (4.66) for women and 11.90 (5.22) for men. Scores for women were significantly lower for all FIQL depression and coping subscales (P < 0.001) and the EQ-5D depression subscale (P < 0.01). EQ-5D index was 0.687 (0.20) for women and 0.835 (0.15) for men (P < 0.001). QoL was negatively affected by female gender (−1.336), anxiety/depression (−1.324) and clinical severity (−0.302), whereas age had a positive impact (0.055 per year) (P < 0.01).

Conclusions

The pathophysiology of fecal incontinence differed between the sexes. For similar severity scores, impact on QoL was higher in women. Gender had the highest impact on QoL compared to other factors. QoL measurements should be part of assessment and treatment protocols.

A systematic review of the literature on the surgical management of recurrent rectal prolapse

AIM

There are no available guidelines to support surgical decision-making in recurrent rectal prolapse. This systematic review evaluated the results of abdominal or perineal surgery for recurrent rectal prolapse, with the aim of developing an evidence-based treatment algorithm.

METHOD

PubMed and MEDLINE databases were searched for all clinical studies involving patients who underwent surgery for recurrent rectal prolapse between 1950 and 2014. The primary outcome measure was the recurrence rate after abdominal or perineal surgery for recurrent rectal prolapse. Secondary outcomes included morbidity, mortality and quality of life data where available.

RESULTS

There were no randomized controlled studies comparing the success rates of abdominal or perineal surgery for recurrent rectal prolapse. Most studies were heterogeneous, of low quality (level IV) and involved small numbers of patients. The follow-up of 144 patients included in the studies undergoing perineal surgery ranged from 8.8 to 81 months, with recurrence rates varying from 0% to 50%. Morbidity ranged from 0% to 17% with no mortality reported. Limited data on quality of life following the Altemeier procedure were available. The follow-up for 158 patients included in the studies who underwent abdominal surgery ranged from 0 to 23 years, during which recurrence rates varied from 0% to 15%. Morbidity rates ranged from 0% to 32% with 4% mortality. No quality of life data were available for patients undergoing abdominal surgery.

CONCLUSION

This systematic review was unable to develop a treatment algorithm for recurrent rectal prolapse due to the variety of surgical techniques described and the low level of evidence within heterogeneous studies. Larger high-quality studies are necessary to guide practice in this difficult area.

Gracilis muscle interposition for rectovaginal and anovaginal fistula repair: a systematic literature review

BACKGROUND

Repair of rectovaginal fistula (RVF) is associated with high recurrence. For this reason gracilis muscle interposition is increasingly being used.

AIM

To evaluate the efficacy of this procedure for RVF repair.

METHOD/SEARCH STRATEGY

A search of PubMed and Medline databases was performed in November 2013 using the text terms and MESH headings 'rectovaginal fistula/fistulation', and 'gracilis muscle', spanning 1980-2013. The search strategy was restricted to articles written in English with available abstracts. Sample size, aetiology of RVF, previous repair attempts, follow-up period, healing rates and complications were recorded and analysed.

RESULTS

Seventeen studies involving 106 patients were analysed. The cause of RVF included inflammatory bowel disease (n = 37 [34.9%]: Crohn's disease [34], ulcerative colitis [3]), pelvic surgery (37 [34.9%]), obstetric injury (9 [8.5%]), malignancy (7 [6.6%]), trauma (5 [4.7%]), miscellaneous (idiopathic, endometriosis, radiation: 11 [10.4%]). Patients had undergone a median number of two previous unsuccessful repairs. At a median follow-up of 21 months, healing had occurred in 33-100% (median 100%) with the largest studies reporting rates between 60% and 90%. Thirteen studies did not report any complications, with the remainder reporting only minor morbidity.

CONCLUSION

Gracilis interposition appears to have a reasonable success rate for RVF repair with acceptable morbidity. It may be considered as one of the first-line treatment options for recurrent RVF.

Ingested foreign bodies: do we need a specific approach when treating inmates?

The management of foreign bodies in the gastrointestinal tract is not standardized. Foreign body ingestions in prisoners are always intentional and inmates can be manipulative, which makes medical decision even more difficult. Our objective is to propose a decisional algorithm for management of foreign body ingestion in prisoners. We reviewed the records of 198 admissions for foreign body ingestion for a 10-year period. Type and number of ingested foreign bodies, radiographic findings, outcome as well as the management method including conservative, endoscopic removal, or surgical treatment were analyzed. Most cases were managed conservatively (87.6%). Endoscopy of the upper gastrointestinal tract was performed in 37 cases with a success rate of 46 per cent. In 9.3 per cent of cases, the final treatment was endoscopic. Only five patients required surgical treatment, being emergent just in one case. We advocate conservative treatment for asymptomatic patients with foreign body ingestion. Endoscopic removal is proposed for pointed objects or objects bigger than 2.5 cm located in the stomach. Objects longer than 6 to 8 cm located in the stomach should be removed by endoscopy or laparoscopy. Patients with objects in the small bowel or colon should be treated conservatively unless there are complications or they fail to progress.

Prospective randomized clinical trial assessing the efficacy of a short course of intravenously administered amoxicillin plus clavulanic acid followed by oral antibiotic in patients with uncomplicated acute diverticulitis

INTRODUCTION

Medical treatment of uncomplicated acute diverticulitis is not standardized, and there is an enormous diversity in clinical practice. Our aim was to demonstrate that uncomplicated diverticulitis can be managed with orally administered amoxicillin plus clavulanic acid and a short hospital admission.

METHODS

A prospective randomized trial was established to compare patients with uncomplicated diverticulitis who received oral antibiotic after a short course of intravenous antibiotic with those who received intravenous antibiotic for a longer period. The antibiotic treatment consisted of amoxicillin plus clavulanic acid 1 g every 8 h. We included 50 patients, 25 in each group. Patients in group 1 began oral antibiotic as soon as they improved and were discharged the day after. Patients in group 2 received intravenous antibiotic for 7 days. Both groups received oral antibiotic at discharge. The endpoint of the study was "failure of treatment," which was defined as the impossibility of discharging on the expected day, emergency admission, or hospital readmission.

RESULTS

Both groups were comparable in patient demographics and clinical characteristics. Most patients clearly improved between 24 and 48 h after admission. There were no significant differences between the groups when comparing failure of treatment. Treatment of patients in group 1 represented a savings in hospitalization costs of 1,244<euro> per patient.

CONCLUSIONS

Most patients with uncomplicated diverticulitis can be managed safely with oral antibiotic; thus, a very short hospital stay is a safe option.

Modulation of the pathology of late xenograft rejection by PAF-antagonist UR-12670 in the hamster-to-rat liver xenotransplant model

PAF antagonists have been used in xenotransplantation to alleviate the pathogenesis of hyperacute rejection. This study evaluated the ability of the PAF antagonist UR-12670 to improve graft function in late xenograft rejection (LXR) in an orthotopic liver xenotransplantation model, and the involvement of PAF (platelet activating factor) in this type of rejection. The recipients of a hamster xenograft received standard immunosuppression (tacrolimus 0.2 mg/kg/30 days, MMF 25 mg/kg/8 days). Study groups: group A, without UR-12670, group B, UR-12670 (20 mg/kg/8 d) and group C, continuous administration of UR-12670 (20 mg/kg/d). Serum levels of xenoantibodies were evaluated by flow cytometry and tissue deposits by immunofluorescence. Immunoblot and indirect immunofluorescence assessed specificity of xenoantibodies. Conventional histology was performed. Continuous administration of UR-12670 improved the histological pattern of liver xenografts, especially necrosis, loss of hepatocytes, hemorrhage, sinusoidal congestion and lymphocyte infiltration. There was not a shift in specificity of xenoantibodies at different times posttransplantation, as demonstrated by immunoblotting and indirect immunofluorescence. UR-12670 administration had a beneficial effect on graft function and considerably improved the histopathological pattern, but it failed to induce tolerance after withdrawal of immunosuppression. UR-12670 had an immunomodulatory effect on cellular response but not on antibody production. There was not a change in the specificity of xenoantibodies produced at LXR compared with pretransplant antibodies.

Acute xenograft rejection, late xenograft rejection and long term survival xenografts in the hamster-to-rat heart transplantation model: histological characterisation under low-dose of FK506

BACKGROUND

Long-term survival studies have been conducted in hamster-to-rat cardiac models with a range of immunosuppressive treatments, but the histological pattern of Late Xenograft Rejection (LXR) has not been outlined. This study offers a detailed description of the histological changes in cardiac xenografts under three different immunological responses.

MATERIALS AND METHODS

Heterotopic hamster-to-Lewis rat cardiac transplant. Recipients were administered an antiproliferative drug (MMF, 25 mg/kg, or CyP, 10 mg/kg, from day -7 to +7 or from day 0 to +7, according to group) and FK506 (0.2 mg/kg; from day 0 to +30 or continuously). Unmodified recipients were used as controls. Conventional histology and indirect immunofluorescence of IgM, IgG and C3 deposits were performed.

RESULTS

In our study, xenografted rats that did not receive treatment developed a pattern of Acute Xenograft Rejection (AXR), with substantial tissue breakdown. Pretreated and treated animals until day 30 post-transplant developed LXR that may present two different histological patterns: one with vascular damage and predominant interstitial haemorrhage, and the other with extensive myocardial fibrosis. Long-term surviving rats (LTS) showed a morphology that was almost normal, with mild fibrosis and vascular endothelium preserved.

CONCLUSIONS

AXR, LXR and LTS in the hamster-to-rat heart transplantation model present a common humoral mechanism although their histopathological patterns are different depending on the length of immunosuppressive treatment but not on the type of antiproliferative drug administered. Pretreatment exerts an effect on fibrosis formation.

Heart and liver xenotransplantation under low-dose tacrolimus: graft survival after withdrawal of immunosuppression

BACKGROUND

The hamster-to-rat xenotransplantation model is a useful model to investigate the features of extended host response to long-surviving xenografts. Early xenoantibody responses are T-cell independent and resistant to tacrolimus. Treatment with the combination of mofetil mycophenolate plus FK506 avoids acute xenograft rejection completely, but after withdrawal of immunosuppression hamster grafts are rejected by a process called late xenograft rejection (LXR).

METHODS

Hamster hearts and livers were transplanted into Lewis rats. Grafted rats were treated with mofetil mycophenolate (25 mg/kg/day) for 8 days and FK506 (0.2 mg/kg/day) for 31 days. Serum IgM and IgG levels were determined by flow cytometry and interferon-gamma levels by ELISA. IgM, IgG, and C3 deposits were measured in tissue by immunofluorescence, and leukocyte infiltration was measured by immunoperoxidase staining. Results. Survival of heart and liver xenografts in the rats was 48+/-4 days and 63+/-8 days, respectively. After cessation of all immunosuppression, hearts were rejected in 18+/-4 days and livers in 33+/-8 days. Production sequences of xenoantibodies in the two organs differed substantially, especially 7 days after transplantation and at the moment of rejection. Quantification of interferon-gamma levels indicated that there were no significant changes after transplantation. Histological and immunohistochemical studies showed signs of humoral mechanism of LXR in rats undergoing heart transplantation and cellular mechanism of LXR in those that received a liver transplant. Conclusions. These observations suggest that rejection in the hamster-to-rat heart xenotransplantation model is mediated by a T cell-independent B-cell response to which a T cell-dependent B-cell response is added in LXR. In the liver xenotransplantation model, our hypothesis is that LXR is mediated by a mixed cell mechanism, involving lymphocytes CD4+ CD45RC+, macrophages, and cytotoxic T lymphocytes. In summary, we have demonstrated and compared the peculiar features of LXR in two different organs.

Liver xenotransplantation: changes in lipid and lipoprotein concentration after long-term graft survival

BACKGROUND/AIMS

Today, scientists devote considerable effort to the study of mechanisms of xenograft rejection, but with liver xenotransplantation (XTx) researchers face the added problem of metabolic incompatibility between species. To date, there have been few studies of molecular xenogeneic interactions, perhaps because little progress has been made in solving immunological problems. This study is an initial analysis of lipoprotein metabolism in a hamster-to-rat hepatic xenotransplantation model.

METHODS

There were 6 experimental groups (n=8): (1) male Sprague-Dawley (S.D.) rats (220-280 g); (2) male Golden Syrian hamsters (100-150 g); (3) S.D. rats, "sham" operation with immunosuppression; (4) S.D. rat-to-S.D. rat alloTx; (5) S.D. rat-to-S.D. rat alloTx with immunosuppression; (6) XTx hamster G.S-to-S.D. rat with immunosuppression. Mofetil mycophenolate (25 mg/kg/d) was administered for 14 days and FK506 (0.2 mg/kg/d) for 45 days (groups 3, 5 and 6). After 24 h fasting, animals were sacrificed (day +50 postransplantation) and a complete lipoprotein profile was determined. Serum lipoproteins were subfractioned by ultracentrifugation in density gradient.

RESULTS

There was a large increase in serum lipid levels in xenografted rats compared with control rats and allografted rats. Xenografted rats presented a severely altered lipoprotein profile compared with normal rats. Surprisingly, the characterisation of lipoproteins in xenografted rats displayed the same composition as donor animals. Histological study did not show signs of alteration of the hepatic architecture.

CONCLUSIONS

Since the liver is the main solid organ co-ordinator of metabolic pathways, such as lipid metabolism, hepatic xenotransplantation makes changes in lipid concentrations in the recipient and also changes in lipid compositions of lipoproteins. Hepatic xenotransplantation is not a feasible solution given the organ's metabolic complexity.

[Usefulness of the genetic study in the diagnosis of medullary carcinoma of the thyroid]

Germ-line mutations in the RET proto-oncogene are associated with multiple endocrine neoplasia type 2A (MEN 2A) and with familial medullary thyroid carcinoma (FMTC). Detection of these mutations allows the identification of the affected kindred members, who will develop medullary thyroid carcinoma (MTC) in 100% of cases. We studied 24 patients of two kindreds (MEN 2A and FMTC). Basal calcitonin levels and pentagastrin-stimulated calcitonin were measured in all patients. The RET mutations were detected by DNA analysis. The RET mutations were identified in 14 patients. Two of them had been operated in the past, 2 refused operation and 4 were living abroad. In the 6 remaining, only one showed a thyroid mass, basal calcitonin was normal in all patients except one, and pentagastrin-stimulated calcitonin was negative in 2 patients. Total thyroidectomy was performed in all cases. Histology showed C-cell hyperplasia in all patients and MTC in 5 of them. In MEN 2A and FMTC DNA analysis allows the identification of RET mutation carriers, in which presymptomatic thyroidectomy allows and improvement in survival.

Vascular occlusion in hepatic resections in cirrhotic rat livers: an experimental study in rats

The aim of this study was to evaluate the tolerance of normothermic liver ischemia with different degrees of hepatic function in cirrhotic rats. Liver cirrhosis was induced by administering carbon tetrachloride (CCl4) in water solution to male Wistar rats. Hepatic function was graded using the plasma levels of antithrombin III, albumin, and bilirubin and the presence of ascites. Rats were distributed in four groups: noncirrhotic (control group), compensated cirrhosis (group A), decompensated cirrhosis (group B), and decompensated cirrhosis with ascites (group C). Groups A, B, and C were significantly different in all four parameters studied (P < .003). Subtotal liver ischemia was performed for periods of 0, 30, 45, 60, and 75 minutes. At the end of the procedure, the nonischemic lobes were resected. Postoperative evolution of alanine aminotransferase, aspartate aminotransferase, and bilirubin levels was also recorded. Survival rates after the same periods of ischemia were statistically different (P < .05): control group, 7 of 7 after 45 minutes (100%), 7 of 7 after 60 minutes (100%), and 4 of 9 after 75 minutes (44%); group A, 7 of 7 after 45 minutes (100%) and 1 of 7 after 60 minutes (14%); group B, 7 of 7 after 0 minutes (100%), 5 of 7 after 30 minutes (71%), and 1 of 7 after 45 minutes (14%); and group C, 0 of 5 after 0 minutes (0%) and 1 of 7 after 30 minutes (14%). No differences were found in the postoperative course of transaminases. However, bilirubin levels found 24 hours and 7 days after ischemia were significantly greater in cirrhotic rats, and this was directly related to the degree of hepatic insufficiency (P < .001). Histological examination of the livers exposed to CCl4 showed features of liver cirrhosis with ductal proliferation. The ischemia time tolerated by cirrhotic rat livers is shorter than the time tolerated by normal rats. Tolerance to hilar vascular occlusion depends on the degree of hepatic insufficiency. Rats with decompensated cirrhosis and ascites do not tolerate any surgical procedure.

Post-transplant lymphoma in a liver allograft

We describe the development of a lymphoma in a liver allograft shortly after orthotopic liver transplantation. Aspiration and core biopsies of the nodule were persistently negative so that a diagnosis could not be made until the patient underwent retransplantation, when examination of the liver resection specimen revealed a B-cell lymphoma. Using a rapid technique based on the polymerase chain reaction, we were able to demonstrate that the tumor was of donor origin.