Rectovaginal Fistula: What is the Role of Martius Flap and Gracilis Muscle Interposition in the Therapeutic Strategy?

BACKGROUND

While numerous treatments exist for management of rectovaginal fistula, none has demonstrated its superiority. The role of diverting stoma remains controversial. Few series include Martius flap in the armamentarium.

OBJECTIVE

Determine the role of gracilis muscle interposition and Martius flap in the surgical management of rectovaginal fistula.

DESIGN

Retrospective cohort study of a pooled prospectively maintained database from 3 centers.

SETTINGS/PATIENTS

All consecutive eligible patients with rectovaginal fistula undergoing Martius flap and gracilis muscle interposition were included from 2001 to 2022.

MAIN OUTCOMES

Success was defined by absence of stoma and rectovaginal fistula.

RESULTS

Sixty-two patients were included with 55 Martius flap and 24 gracilis muscle interposition performed after failures of 164 initial procedures. Total length of stay was longer for gracilis muscle interposition by 2 days (p = 0.01) without a significant difference in severe morbidity (20% vs. 12%, p = 0.53). 27% of Martius flap were performed without stoma, without impact on overall morbidity (p = 0.763). Per-patient immediate success rates were not significantly different between groups (35% vs. 31%, p = 1.0). Success of gracilis muscle interposition after failure of Martius flap was not significantly different from an initial gracilis muscle interposition (p = 1.0). The immediate success rate rose to 49.4% (49% vs. 50%, p = 1.0) after simple perineal procedures. After a median follow-up of 23 months, there was no significant difference detected in success rate between the two procedures (69% vs. 69%, p = 1.0). Smoking was the only negative predictive factor (p = 0.02).

LIMITATIONS

By its retrospective nature, this study is limited in its comparison.

CONCLUSION

This novel comparison between Martius flap and gracilis muscle interposition suggests that Martius flap presents several advantages, including shorter length of stay, similar morbidity, and success. Proximal diversion via a stoma for Martius flap does not appear mandatory. Gracilis muscle interposition could be reserved as a salvage procedure after Martius flap failure. See Video Abstract.

Does an Ileoanal Anastomosis Decrease the Rate of Successful Pregnancy Compared With an Ileorectal Anastomosis? A National Study of 1491 Patients

OBJECTIVE

Report the rate of successful pregnancy in a national cohort of women with either an ileal pouch anal (IPAA) or ileorectal (IRA) anastomosis constructed after colectomy for inflammatory bowel disease (IBD) or polyposis.

BACKGROUND

Fertility after IPAA is probably impaired. All available data are corroborated by only small sample size studies. It is not known whether construction of IPAA versus IRA influences the odds of subsequently achieving a successful pregnancy, especially with increased utilization of the laparoscopic approach.

METHODS

All women (age: 12-45 y) undergoing IRA or IPAA in France for polyposis or IBD, between 2010-2020, were included. A control population was defined as women aged from 12 to 45 years undergoing laparoscopic appendicectomy during the same period. The odds of successful pregnancy were studied using an adjusted survival analysis.

RESULTS

A total of 1491 women (IPAA=872, 58%; IRA=619, 42%) were included. A total of 220 deliveries (15%) occurred during the follow-up period of 71 months (39-100). After adjustment, the odds of successful pregnancy was not significantly associated with type of anastomosis (after IPAA: Hazard Ratio [HR]=0.79, 95% confidence interval=0.56-1.11, P =0.17). The laparoscopic approach increased the odds of achieving successful pregnancy (HR=1.79, 95% confidence interval=1.20-2.63, P =0.004). IRA and IPAA significantly impacted fertility when compared with the control population ( P <0.001).

CONCLUSIONS

In this large cohort study, total colectomy for polyposis or IBD was associated with reduced fertility compared with the general population. No difference in odds of achieving successful pregnancy was found between IRA and IPAA after adjustment. This analysis suggests laparoscopic surgery may be associated with greater likelihood of pregnancy.

Detailed analysis of in-hospital transmission of SARS-CoV-2 using whole genome sequencing

BACKGROUND

Hospital transmission of SARS-CoV-2 has proved difficult to control, with healthcare-associated infections troublesome throughout.

AIM

To understand factors contributing to hospital transmission of infections, which is necessary for containing spread.

METHODS

An outbreak of 56 staff and patient cases of COVID-19 over a 31-day period in a tertiary referral unit is presented, with at least a further 29 cases identified outside of the unit and the hospital by whole genome sequencing (WGS).

FINDINGS

Transmission is documented from staff to staff, staff to patients, and patients to staff, showing disruption of a tertiary referral service, despite implementation of nationally recommended control measures, superior ventilation, and use of personal protective equipment. There was extensive spread from the index case, despite this patient spending only 10 h bed bound on the ward in strict cubicle isolation and with an initial single target low level (C_T = 32) polymerase chain reaction test.

CONCLUSION

This investigation highlights how effectively and rapidly SARS-CoV-2 can spread in certain circumstances. It raises questions about infection control measures in place at the time and calls into question the premise that transmissibility can be reliably detected by using lower sensitivity rapid antigen lateral flow tests. We also highlight the value of early intervention in reducing impact as well as the value of WGS in understanding outbreaks.

Impact of operation duration on postoperative outcomes of minimally-invasive right colectomy

AIM

Operation time (OT) is a key operational factor influencing surgical outcomes. The present study aimed to analyse whether OT impacts on short-term outcomes of minimally-invasive right colectomies by assessing the role of surgical approach (robotic [RRC] or laparoscopic right colectomy [LRC]), and type of ileocolic anastomosis (i.e., intracorporal [IA] or extra-corporal anastomosis [EA]).

METHODS

This was a retrospective analysis of the Minimally-invasivE surgery for oncological Right ColectomY (MERCY) Study Group database, which included adult patients with nonmetastatic right colon adenocarcinoma operated on by oncological RRC or LRC between January 2014 and December 2020. Univariate and multivariate analyses were used.

RESULTS

The study sample was composed of 1549 patients who were divided into three groups according to the OT quartiles: (1) First quartile, <135 min (n = 386); (2) Second and third quartiles, 135-199 min (n = 731); and (3) Fourth quartile ≥200 min (n = 432). The majority (62.7%) were LRC-EA, followed by LRC-IA (24.3%), RRC-IA (11.1%), and RRC-EA (1.9%). Independent predictors of an OT ≥ 200 min included male gender, age, obesity, diabetes, use of indocyanine green fluorescence, and IA confection. An OT ≥ 200 min was significantly associated with an increased risk of postoperative noninfective complications (AOR: 1.56; 95% CI: 1.15-2.13; p = 0.004), whereas the surgical approach and the type of anastomosis had no impact on postoperative morbidity.

CONCLUSION

Prolonged OT is independently associated with increased odds of postoperative noninfective complications in oncological minimally-invasive right colectomy.

C-reactive protein values after surgery for inflammatory bowel disease: is it still a good marker for intra-abdominal complication? A retrospective cohort study of 347 procedures : CRP after inflammatory bowel disease surgery

PURPOSE

C-reactive protein (CRP) is a useful predictive test to early detect abdominal complication after colorectal surgery. Inflammatory bowel disease (IBD) is responsible for chronic inflammation and abnormal basal CRP that could influence the interest of its management after abdominal surgery. The aim of this study is to evaluate CRP as an indicator of postoperative complication in a specific IBD population.

METHODS

Retrospective study of patients undergoing ileocolic resection or ileal pouch-anal anastomosis for IBD between 2012 and 2019.

RESULTS

Ileocolic resection represents 242 patients and ileal pouch-anal anastomosis 105 patients. CRP was significantly higher at an early (105.2 ± 56.0 vs 128.1 ± 69.8; p = 0.008) and late stage (112.9 ± 72.8 vs 185.3 ± 111.5; p < 0.0001) for patients having an intra-abdominal complication. A BMI > 25 kg/m² (p = 0.04) and an open surgical approach (p = 0.009) were associated with higher CRP levels in the first postoperative days (POD). In multivariate analysis, preoperative steroid use (p = 0.06), CRP at POD 3 > 100 mg/L (p = 0.003), and a rise between CRP values (p = 0.007) at 48 h were significantly associated with intra-abdominal complication. A CRP at POD 1 < 75 mg/L was associated with a lower rate of intra-abdominal complication (p = 0.01). A score dividing patients into 3 groups according to these values showed significant differences in intra-abdominal complication and anastomotic leakage rates.

CONCLUSION

CRP is a useful predictive marker to detect abdominal complication after surgery in IBD population. Measurement of CRP can help to reduce hospitalization stay and orientate towards complementary examinations.

Parent report of child behaviour: Findings from the Flint Registry cohort

BACKGROUND

Children in Flint, Michigan, have multiple risk factors for behavioural challenges, including exposure to lead during the Flint water crisis. However, their behavioural health status is largely unknown. Robust data from the Flint Registry can help understand the burden of behavioural outcomes and inform the allocation of resources.

OBJECTIVES

This population-level evaluation of Flint children's behavioural outcomes aims to answer the question: What is the burden of parent-reported child behaviour problems in Flint Registry enrolled children?

METHODS

This cross-sectional study describes parent-reported behavioural outcomes of children 2-17 years old who enrolled in the Flint Registry between December 2018 and December 2020. Parents/guardians completed behavioural assessments including the Behavior Assessment System for Children (BASC-3) Parent Rating Scale and Behavior Rating Inventory of Executive Function (BRIEF2) Screening Parent Form. Demographics of enrolees were compared with census data. Composite BASC-3 T scores were compared with national norms. Distributions for clinically relevant categories of BASC-3 and BRIEF2 scores were examined across age and sex groups.

RESULTS

Of the 3579 children included in this study (mean age 9.73 ± 3.96 years), about half were female and 79.7% were eligible for free or reduced-price lunch. Almost half of the children were reported to have clinically concerning scores on the BASC-3 Parent Rating Scale (44.7%) and the BRIEF2 Screening Parent Form (46.7%). Across most age and sex groupings, the reported adaptive skills were relatively low and behaviour symptoms relatively high.

CONCLUSIONS

Results reveal a substantial burden of parent-reported behavioural problems in Flint Registry children. This is clinically significant and indicates that a large number of children may require comprehensive neuropsychological evaluation and potential medical and/or educational services. Recognising the potential for long-term manifestations of childhood exposures to environmental hazards, longitudinal surveillance is critical to continue to identify and support participants.

Redo-surgery after failed colorectal or coloanal anastomosis: Morbidity, mortality and factors predictive of success. A retrospective study of 200 patients

AIM

In cases of anastomotic failure after colorectal (CRA) or coloanal anastomosis (CAA), revision of the anastomosis is an ambitious surgical option that can be proposed in order to maintain bowel continuity. Our aim was to assess postoperative morbidity, risk of failure and risk factor for failure in patients after CRA or CAA.

METHODS

All consecutive patients who underwent redo-CRA/CAA in our institution between 2007-2018 were retrospectively included. The success of redo-CRA/CAA was defined by the restoration of bowel continuity 12 months after the surgery.

RESULTS

Two hundred patients (114 male: 57%) were analyzed. The indication for redo-CRA/CAA was chronic pelvic infection in 74 patients (37%), recto-vaginal or urinary fistula in 59 patients (30%), anastomotic stenosis in 36 patients (18%) and redo anastomosis after previous anastomosis takedown in 31 patients (15%). Twenty-three percent of the patients developed a severe postoperative complication. Anastomotic leakage was diagnosed in 39 patients (20%). One-year-success of the redo-CRA/CAA was obtained in 80% of patients. In multivariate analysis, only obesity was associated with redo-CRA/CAA failure (p = 0.042). We elaborated a pre-operative predictive score of success using the four variables: male sex, age > 60 years, obesity and history of pelvic radiotherapy. The success of redo-CRA/CAA was 92%, 86%, 80% and 62% for a preoperative predictive score value of 0, 1, 2 and ≥3, respectively (p = 0.010).

CONCLUSIONS

In case of failure of primary CRA/CAA, bowel continuity can be saved in 4 out of 5 patients by redo-CRA/CAA despite 23% suffering severe postoperative morbidity.

Nonmetastatic ypt0 rectal cancer after neoadjuvant treatment and total mesorectal excision: Lessons from a retrospective multicentric cohort of 383 patients

BACKGROUND

A better understanding of pathological features and oncological survival in ypT0 rectal cancer after neoadjuvant chemoradiotherapy is required to improve patient selection criteria for rectal-preserving approach by local excision. Our aim was to define risk of lymph node metastasis and oncological outcomes in ypT0 rectal cancer after chemoradiotherapy and total mesorectal excision.

METHODS

All consecutive patients who underwent total mesorectal excision for a nonmetastatic rectal adenocarcinoma classified ypT0 after neoadjuvant chemoradiotherapy, with or without locoregional lymph node involvement (ypN+ or ypN-), in 14 French academic centers between 2002 and 2015 were included. Data were collected retrospectively. Overall and disease-free survival were explored.

RESULTS

Among the 383 ypT0 patients, 6% were ypN+ (23/283). Before chemoradiotherapy, 86% (327/380) were staged cT3-T4 and 41% (156/378) were staged cN+. The risk of ypN+ did not differ between cT3-T4 and cT1-T2 patients (P = .345) or between cN+ and cN- patients (P = .384). After a median follow-up of 61.1 months, we observed 95% confidence interval (92%-97%) of 5-year overall survival and 93% confidence interval (91%-96%) of 5-year disease-free survival. In Cox multivariate analysis, overall survival was altered by intra-abdominal septic complications (hazard ratio = 2.53, confidence interval [1.11-5.78], P = .028). Regarding disease-free survival, ypN+ status and administration of adjuvant chemotherapy were associated with a reduced disease-free survival (P = .001 for both). cT3/T4 staging and cN+ staging did not modify overall survival (P = .332 and P = .450) nor disease-free survival (P = .862 and P = .124).

CONCLUSION

The risk of lymph node metastasis and the oncological survival do not depend on the initial cT or cN staging in cases of ypT0 complete rectal tumor regression.

EP.TU.4973 year oncological outcomes of robotic-assisted versus laparoscopic rectal cancer resections – a single centre experience

Background

Robotic-assisted minimally invasive surgery (MIS) for rectal cancer is a relatively new technique. Studies to date suggest that short term outcomes including TME quality, margin status, lymph node retrieval and 30-day morbidity and mortality are equivalent in robotic-assisted and laparoscopic MIS for rectal cancer. By contrast, there is a paucity of data on the medium and long-term oncologic safety of robotic-assisted comparative to laparoscopic surgery for rectal cancer.

Methods

A retrospective review was conducted of all robotic-assisted (n = 31) and laparoscopic (n = 23) rectal cancer cases performed at our institution between January 2016 to December 2018. Inclusion criteria were patients scheduled electively for a laparoscopic or robotic-assisted resection of rectal cancer (anterior resection or abdomino-perineal resection). Patients with distant metastases at presentation, those who proceeded to surgery as an emergency and those with a non-colorectal primary were excluded from analysis.

Results

A total of 54 (n = 54) cases met the inclusion criteria and were included in the final analysis. The median follow-up was 34 months. Of the 54, 21 patients received neoadjuvant chemoradiotherapy prior to definitive surgery.

No significant difference was detected in local recurrence rates (p = 0.5), overall survival (p = 0.7) or disease-free survival (p = 0.8) between the robotic-assisted and laparoscopic cohorts.

Conclusion

In this series, robotic-assisted rectal cancer resections were associated with equivalent medium term oncological outcomes as laparoscopic procedures.

However, given the small numbers in this cohort, outcomes from larger scale datasets will be required to confirm these results.

EP.TU.493Attitudes of Irish General Surgery trainees to Robotic-Assisted Surgery

Background

While the use of robotic-assisted surgery is now mainstream for procedures such as robotic prostatectomy, its role in general surgery is less well established. Access to training in robotics for general surgery trainees in the Republic of Ireland is variable. Further, there is no data on attitudes of Irish trainees towards the role of robotics. We aimed to establish attitudes of Irish general surgery trainees towards the perceived utility of robotic surgery as well as access and satisfaction with training.

Methods

A survey was disseminated to trainees in the Republic of Ireland enrolled in a General Surgery training scheme via email and social media. Data collected included stage of training, intended subspecialty, interest in developing robotic skills, previous exposure to robotic surgery, satisfaction with current access to robotic training and opinion on formally incorporating training in robotics into the general surgery curriculum.

Results

The response rate was 44.8%. Of these, 83% reported interest in training in robotics and 69% anticipated using the technology regularly in consultant practice. Previous exposure to robotic-assisted surgery was significantly predictive of interest in developing the skillset (p = 0.014). Over 71% of trainees reported that they were not satisfied with access to robotic training. Of those satisfied with access, 40% felt there was a role for incorporating robotic training into the curriculum, compared to 68% of those dissatisfied.

Conclusion

Irish general surgery trainees perceive robotic-assisted surgery to be highly relevant to their future practice. There is an unmet need to provide additional training in the skillset.

143 Massive Intra-Hepatic Subcapsular Liver Haematoma Post-Laparoscopic Cholecystectomy- A Rare Complication of a Common Procedure'

Case Presentation

A 59-year-old female presented with symptomatic biliary colic. Her past medical history was noted for obesity (BMI&gt;50). She underwent an elective LC with an uncomplicated intraoperative course; however, post-operatively she developed hypovolaemic shock with an acute haemoglobin drop requiring fluid resuscitation and blood transfusion. Emergency CT revealed a massive subcapsular haematoma measuring 21cm×3.1cm× 17cm at the right liver margin without evidence of ongoing bleeding. She was managed conservatively- as per a tertiary hepatobiliary surgery centre’s advice- with meticulous clinical observations, serial monitoring of haemoglobin, and repeat CT to assess for interval progressions. She progressed well with conservative management and did not require surgical or radiological intervention. A follow-up liver sonography performed eight weeks post-discharge confirmed a complete resolution.

Conclusion

Giant ISH is an exceedingly rare but life-threatening complication following LC which merits special attention. Our case demonstrates the necessity of close postoperative monitoring of patients undergoing LC and considering the possibility of ISH in those who experience refractory postoperative hypotension. It also highlights the decisive role of diagnostic imaging in securing a timely and accurate diagnosis of post-LC ISH.

237 Massive Subcapsular Intra-hepatic Haematoma Post-laparoscopic Cholecystectomy: A Rare Complication of a Common Procedure

Abstract

Laparoscopic cholecystectomy (LC) is currently considered the gold standard for the management of symptomatic gallbladder stones disease. Specific complications remain challenging, particularly postoperative bleeding, bile leak, and bile duct injury. We report a rare case of a giant intrahepatic subcapsular haematoma (ISH) complicating LC.

Case Presentation

A 59-year-old female presented with symptomatic biliary colic. Her past medical history was noted for obesity (BMI &gt; 50). She underwent an elective LC with an uncomplicated intraoperative course; however, post-operatively she developed hypovolaemic shock with an acute haemoglobin drop requiring fluid resuscitation and blood transfusion. Emergency CT revealed a massive subcapsular haematoma measuring 21cm×3.1cm× 17cm at the right liver margin without evidence of ongoing bleeding. She was managed conservatively- as per a tertiary hepatobiliary surgery centre’s advice- with meticulous clinical observations, serial monitoring of haemoglobin, and repeat CT to assess for interval progressions. She progressed well with conservative management and did not require surgical or radiological intervention. A follow-up liver US performed eight weeks post-discharge confirmed a complete resolution.

Conclusions

Giant ISH is an exceedingly rare but life-threatening complication following LC which merits special attention. Our case demonstrates the necessity of close postoperative monitoring of patients undergoing LC and considering the possibility of ISH in those who experience a refractory postoperative hypotension. It also highlights the decisive role of diagnostic imaging in securing a timely and accurate diagnosis of post LC-ISH

Adaptive Behavior as an Alternative Outcome to Intelligence Quotient in Studies of Children at Risk: A Study of Preschool-Aged Children in Flint, MI, USA

Intelligence quotient (IQ) is commonly measured in child development studies, while adaptive behavior is less frequently considered. Given its associations with functional outcomes in children with neurodevelopmental disabilities, adaptive behavior may be a useful outcome in general population samples, as well. This study aimed to compare social and environmental correlates of adaptive behavior vs. IQ in a sample of preschoolers exposed to the Flint water crisis (N = 184). Mother-child dyads were recruited from the community and administered a comprehensive battery to obtain information about child neurodevelopmental functioning, including direct assessment of IQ via the Wechsler Preschool and Primary Scale of Intelligence and assessment of parent-reported adaptive functioning via the Vineland Adaptive Behavior Scales. Multiple social environmental factors were explored as potential correlates of child outcomes (i.e., IQ and adaptive behavior), and robust correlates were identified using a data-driven approach [i.e., least absolute shrinkage and selection operator (LASSO) regression]. We then examined associations between the LASSO-selected predictors and IQ and adaptive behavior while controlling for child age, child sex, and maternal age. Children in this sample showed relative strength in adaptive behaviors, with scores in the adequate range, while average IQs fell in the low-average range. Adaptive behavior was significantly associated with maternal nurturance practices, while IQ was associated with the maternal education level. Implications for the use of adaptive behavior as an outcome measure in studies of children at an increased risk for neurodevelopmental problems are discussed.

Evolving pattern of fetal movements throughout a healthy pregnancy

A 31-year-old woman with a history of stillbirth due to placental abruption at 29 weeks' gestation and one first trimester miscarriage documented a continuous record of her perceived fetal movements from 28 to 38 weeks' gestation. Repeated ultrasound examinations confirmed a viable pregnancy, with normal growth, liquor volume and Doppler profile. She delivered a healthy male infant at 38 weeks and 3 days' gestation. The data collected give a detailed record of fetal activity in a healthy pregnancy. Perceived fetal activity increased as pregnancy progressed and was greatest in the evenings. We also found that clusters of movements, which have previously been reported as protective against stillbirth, were felt earlier on in pregnancy.

Computer-assisted technology for enhanced abdominal surgery

The application of computer-based technology to surgery has the potential to enhance the accuracy and outcomes of surgical procedures and perioperative care. Such innovative technologies include the integration of artificial intelligence into surgical decision-making, and the use of three-dimensional (3D) visual imaging, other real-time imaging techniques, and 3D printing technology.

The Role of Organoids as a Novel Platform for Modeling of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic relapsing-remitting immune-mediated disorder affecting the gut. It is common in Westernized regions and is increasing in incidence in developing countries. At a molecular level, intrinsic deficiencies in epithelial integrity, mucosal barrier function, and mechanisms of immune response and resolution contribute to the development of IBD. Traditionally two platforms have been utilized for disease modeling of IBD; in-vitro monolayer cell culture and in-vivo animal models. Both models have limitations, including cost, lack of representative cell types, lack of complexity of cellular interactions in a living organism, and xenogeneity. Organoids, three-dimensional cellular structures which recapitulate the basic architecture and functional processes of the organ of origin, hold potential as a third platform with which to investigate the pathogenesis and molecular defects which give rise to IBD. Organoids retain the genetic and transcriptomic profile of the tissue of origin over time and unlike monolayer cell culture can be induced to differentiate into most adult intestinal cell types. They may be used to model intestinal host-microbe interactions occurring at the mucosal barrier, are amenable to genetic manipulation and can be co-cultured with other cell lines of interest. Bioengineering approaches may be applied to render a more faithful representation of the intestinal epithelial niche. In this review, we outline the concept of intestinal organoids, discuss the advantages and disadvantages of the platform comparative to alternative models, and describe the translational applications of organoids in IBD.

Impact of targeted trainer feedback via video review on trainee performance of laparoscopic cholecystectomy

INTRODUCTION

Tools for improving operative performance for surgical trainees are increasingly desirable, particularly in the context of EWTD and 'run-through' training programmes. In addition, positive direct trainer feedback to trainees can improve skill acquisition and motivation, whilst negative feedback may have the opposite effect.¹ We aimed to examine the impact of targeted trainer feedback based on video analysis on trainee confidence and objective operative performance in laparoscopic cholecystectomy.

METHODS

Selected procedures designated as training cases were recorded. These were assessed by the trainers using the Independence-Scaled Procedural Assessment Score for laparoscopic cholecystectomy. Targeted feedback based on video review of selected procedures was then delivered by the trainers to the trainees. Trainees completed a self-reported questionnaire based on their response to this feedback. Subsequent to the feedback intervention, further training procedures were recorded and assessed.

RESULTS

A total of 6 trainees and 4 trainers participated in the study. For the pre-intervention assessment 15 cases were recorded, with a further 13 for the post-intervention assessment (total n = 28). The overall scores for the procedures performed post video feedback were improved, with a trend towards statistical significance (p = 0.08). However, there was a statistically significant improvement in the scores for performance of the triangle of Calot dissection after the feedback intervention (p = 0.009). The response rate to the questionnaire was 100%, with all trainees agreeing that they felt more confident and competent after the feedback intervention.

CONCLUSION

Targeted feedback to trainees based on post-procedure video review improves trainee confidence and may also improve performance. ACGME Core Competencies; Patient Care and Procedural Skills; Practice Based Learning and Improvement.

Quality of life in patients with upper GI malignancies managed by a strategy of chemoradiotherapy alone versus surgery

BACKGROUND AND OBJECTIVES

Neoadjuvant chemoradiotherapy (nCRT) induces a pathological complete response (pCR) in 25-85% of oesophago-gastric cancer. As surgery entails morbidity and mortality risks and quality of life (QL) impairment, its avoidance in patients without residual disease is desirable. This study aimed to compare quality of life of patients with a cCR who chose surveillance with those who chose surgery.

METHODS

Four groups of patients were studied. Group 1(n = 31) were controls; Group 2 (n = 26) had chemoradiotherapy only; Group 3 (n = 31) had oesophagectomy after nCRT; Group 4 (n = 26) had gastrectomy alone. A 33-point novel questionnaire was administered at two 3 month time points. Participants were also interviewed with a validated questionnaire.

RESULTS

Mean(±sd) quality of life scores in cCR patients offered surveillance (28.9 ± 4.5) were superior to patients undergoing oesophagectomy (32.3 ± 58. p=0.042) or gastrectomy (33.19 ± 5.9, p=0.004). This result was replicated in the validated questionnaire (p=0.017). There was a trend towards increased reflux-related respiratory symptoms in the oesophagectomy group (7.3 ± 2.2 vs 6.5 ± 1.9; p=0.396) and towards early dumping (8.2 ± 1.4 vs 7.1 ± 1.; p=0.239) and vagotomy-related symptoms (1.82 ± 0.9 vs 1.4 ± 0.6; p=0.438) in the gastrectomy group.

CONCLUSIONS

Avoidance of surgery in cCR patients is rewarded with a superior quality of life to those undergoing surgery.

The approach to an isolated close anterior margin in breast conserving surgery

INTRODUCTION

Although close radial margins after breast-conserving surgery routinely undergo re-excision, appropriate management of patients with close anterior margins remains a topic of controversy. An increasing body of literature suggests that re-excision of close anterior margins yields low rates of residual malignancy and may only be necessary in selected patients. The aim of this study was to examine the management of close anterior margins after breast conserving surgery in a single institution and to analyse the rate of residual disease in re-excised anterior margins.

METHODS

All patients having breast conserving surgery at St Vincent's University Hospital from January 2008 to December 2012 were reviewed retrospectively. Data collected included patient demographics, tumour characteristics, margin positivity, re-excision rates and definitive histology of the re-excision specimens. A close margin was defined as les than 2 mm.

RESULTS

A total of 930 patients were included with an average age of 65 years (range 29-94 years). Of these, 121 (13%) had a close anterior margin. Further re-excison of the anterior margin was carried out in 37 patients (30.6%) and a further 16 (13.2%) proceeded to mastectomy. Residual disease was found in 18.5% (7/36) of those who underwent re-excision and 7/16 (43.75%) of those who underwent mastectomy. Overall, 11.57% (14/121) of patients with close anterior margins were subsequently found to have residual disease.

CONCLUSION

The low yield of residual disease in re-excised anterior margins specimens supports the concept that routine re-excision of close anterior margins is not necessary. Further research is required to definitively assess its influence on the risk of local recurrence.

Magnetic Stent Removal in a Nurse Led Clinic; a Nine Month Experience

Ureteric stents are frequently inserted post endourological procedures. However, subsequent endoscopic stent removal requires a second procedure for the patient and the availability of necessary resources. Longer duration of indwelling stents can lead to increased risk of symptoms and complications. The use of magnetic stents removed with a magnetic retrieval device (BlackStar©), offers an alternative which obviates the need for cystoscopy. We assessed the outcomes for this novel method of stent removal in our institution. A retrospective analysis was performed of all patients undergoing magnetic stent insertion and subsequent removal in a nurse-led clinic over a nine-month period. Patients were followed up with a prospective validated Ureteral Stent Symptoms Questionnaire (USSQ)3. A cost analysis was also performed. In total, 59 patients were treated using magnetic stents. The complication rate was low (6.7%). The median duration of indwelling stent was 5.8 days (range 1-11 days). Patients reported haematuria and lower urinary tract symptoms but >90% experienced no functional impairment with minimal days of employment lost (mean 0.75 days). All patients reported satisfaction with nurse-led stent removal and 97% were happy to have stents removed via this method in the future. The total financial savings were estimated at €47,790 over this period. Nurse-led removal of magnetic stents is safe and well tolerated by patients and enables expedient stent removal. It also provides a significant cost benefit and frees up valuable endoscopic resources.

Synovial chondroma in Hoffa's fat pad: Case report and literature review of a rare disorder

•

Synovial chrondroma is a rare condition of which the aetiology remains unclear. Large palpable lesions represent an atypical presentation.

•

The diagnosis is often not immediately apparent. However it is usually suggested by radiologic investigation and confirmed on histology.

•

Disease recurrence is not infrequent after excision (15–23%) and patients should be counselled regarding this.

•

Malignant transformation whilst uncommon has been described. At present no definite criteria exist in order to make the diagnosis of malignancy.

•

Due to the above risks of recurrence and malignancy, long term follow up of affected patients is advised.

Introduction

Synovial chrondomatosis is a rare disorder characterised by the development of hyaline cartilage from the synovial membrane. Large isolated lesions in the Hoffa's fat pad are an uncommon entity.

Presentation of case

A 33 year old gentleman presented complaining of progressive knee pain associated with an enlarging lesion on the anterior aspect of the right knee, with associated locking and giving way. Examination revealed a firm 4 × 5 cm lesion adjacent to the patellar tendon.

Subsequent CT and MRI demonstrated a lesion in the inferior aspect of Hoffa’s fat pad, with a second lesion adjacent to the proximal tibiofibular joint, in addition to advanced degenerative changes and a meniscal tear.

He proceeded to excisional biopsy. Histological analysis was consistent with a solitary synovial osteochondroma. There were no atypical features suggestive of malignancy.

Discussion

Synovial chondromatosis is a rare disorder affecting the synovial joints. The underlying pathophysiology is thought to be metaplastic change of the synovium to hyaline cartilaginous tissue. Transformation to malignancy has been described but is uncommon with an estimated risk of 5%. It is 1.5–2 times as prevalent in males versus females. Symptoms which patients may complain of include pain;locking and giving way; and palpable masses.

The management usually entails removal of the mass lesion with or without accompanying synovectomy. Recurrence of disease may occur in up to 15–23% of patients.

Conclusion

Synovial chrondromatosis is a rare but well recognised condition. Long term follow up is advised in view of the risk of recurrence and malignant transformation.

Running in the family: A rare diagnosis of familial papillary thyroid cancer

INTRODUCTION

Whilst inherited medullary thyroid cancer has been extensively reported, familial non-medullary thyroid cancer is a rare and less well described clinical entity. Familial forms of the disease demonstrate more aggressive features than sporadic non-medullary thyroid cancer.

PRESENTATION OF CASE

A 54 year old lady was referred with globus on a background of a longstanding goitre. Three first degree relatives had a history of non-medullary thyroid carcinoma. Investigations revealed a papillary thyroid carcinoma and the patient proceeded to total thyroidectomy and ipsilateral Level VI neck dissection, followed by adjuvant radioiodine ablation.

DISCUSSION

Familial papillary thyroid carcinoma syndrome is defined as three or more first degree relatives diagnosed with the disease in the absence of other known associated syndromes. It is often associated with the presence of benign thyroid disorders, and is characterised by the early onset of multi-focal bilateral locally advanced tumours.

CONCLUSION

Familial papillary thyroid cancer is a rare clinical entity but should be considered where ≥3 first degree relatives are diagnosed with non-medullary thyroid cancer. It is necessary to exclude other familial tumour syndromes to make the diagnosis. It demonstrates more aggressive features with higher rates of local recurrence than its sporadic counterpart, and therefore mandates more aggressive management than might otherwise be indicated. Screening of first degree relatives should be considered.

SUMMARY

The case of a 54 year old female diagnosed with familial non-medullary thyroid carcinoma is reported.

Rates of bluetongue virus transmission between Culicoides sonorensis and sheep

Two experiments were undertaken to estimate the transmission rates of bluetongue virus (BTV) serotype 1 between a biting midge vector, Culicoides sonorensis (Wirth & Jones) (Ceratopogonidae), and a natural host, sheep. In an experiment to measure the transmission rate from vector to host (V-->H), six batches of one, five and 20 intrathoracically infected midges were fed on a total of 18 bluetongue (BT)-naïve sheep. The sheep were then monitored for 21 days for clinical signs of BT, viraemia and antibody response. All sheep fed on by five or 20 midges and five of six sheep fed on by just one midge showed signs of BT, were viraemic and developed antibody. The sixth sheep fed on by a single infected midge did not show signs of BT or have detectable viraemia; it did, however, develop a weak antibody response. A bite from a single infected midge is therefore able to transmit BTV to naïve sheep with 80-100% efficiency. Sheep fed upon by larger numbers of infected midges took less time to reach maximum viraemia and developed stronger antibody responses. Sheep exposed to greater amounts of BTV in feeding midges developed a higher level of viraemia and stronger antibody responses. In a second experiment to measure the transmission rate from host to vector (H-->V), batches of up to 500 uninfected female C. sonorensis fed every 1-2 days on two experimentally infected sheep during the course of infection. Of 3929 engorged midges that were individually titrated after surviving the extrinsic incubation period, only 23 (0.6%) were infected with BTV. Viraemia in the sheep extended for up to 19 days post-inoculation. No infected midges, however, were detected from 14 days post-infection.

Modelling the distribution of bluetongue vectors

Recent epizootics of Culicoides-borne disease in the Mediterranean Basin have stimulated the development of climate-driven models for vectors. Predictor variables come from two main sources, weather data and satellites. Generally, models for Culicoides imicola combine temperature and moisture variables. The best weather models explain 75-85% of the variance in observed data for C. imicola, but satellite models perform better (85-95% of variance). Predictions of models for other regions appear mixed, with successes and failures. The failures indicate the need to: explore and incorporate other factors that may affect Culicoides populations, such as soil characteristics, host type and wind speed. Develop more complex models, recognising that different climate variables affect different stages of the life-cycle e.g. biological models. The very rapid spread in the distribution of C. imicola in recent years suggests that global warming may be a less important driver of change than other, currently unknown, factors.

Experimental models for the investigation of female sexual function and dysfunction

There have been limited anatomic and physiological investigations of the female sexual arousal response. A broader understanding of the physiologic mechanisms of female sexual arousal function is required to improve the management of women with sexual dysfunction. Three experimental test systems have been developed to understand better the biochemical and physiological mechanisms of female sexual arousal response. An in vivo animal model was developed to record physiological and hemodynamic changes in the clitoris and vagina following pelvic nerve stimulation and administration of vasoactive agents and physiological modulators. In vitro organ baths of clitoral and vaginal tissue were utilized to investigate mechanisms involved in the regulation of smooth muscle contractility. In addition, primary cell cultures of human and animal clitoral and vaginal smooth muscle cells were developed to investigate signal transduction pathways modulating smooth muscle tone. In vivo studies revealed hemodynamic changes in vagina and clitoris in response to pelvic nerve stimulation, vasodilators and physiological modulators. Organ bath studies have demonstrated that clitoral and vaginal smooth muscle tone is affected by non-adrenergic and non-cholinergic neurotransmitters, and the presence of functional alpha 1 and alpha 2 adrenergic receptors in these tissues has been established through biochemical studies. These changes are regulated by the tone of vascular and non-vascular smooth muscle in the vagina and clitoris. Primary cell culture studies have suggested that several physiological modulators such as vasoactive intestinal polypeptide (VIP), nitric oxide (NO), and prostaglandin E (PGE) regulate vaginal smooth muscle contractility. Data from experimental models have provided a preliminary understanding of the mechanisms of the female sexual arousal response.

Management of patients with chronic obstructive pulmonary disease in ICU and promotion of smoking cessation

Chronic obstructive pulmonary disease (COPD) is an increasingly significant health problem. Pathophysiological effects of smoking are outlined in this paper. Management of patients with COPD in ICU is discussed. Treatment options available to treat COPD patients are described. Health promotion and aids available to assist cessation of smoking are discussed.

TrkA amino acids controlling specificity for nerve growth factor

Neurotrophins are important for the development and maintenance of the vertebrate nervous system, mediating their signal into the cell by specific interaction with tyrosine kinase receptors of the Trk family. The extracellular portion of the Trk receptors has been previously proposed to consist of a cysteine-rich motif, a leucine-rich motif, a second cysteine-rich motif followed by two immunoglobulin-like domains. Earlier studies have shown that a major neurotrophin-binding site in the Trk receptors resides in the second immunoglobulin-like domain. Although the individual amino acids in TrkA involved in binding to nerve growth factor (NGF) and those in TrkC involved in binding to neurotrophin-3 have been mapped in this domain, the Trk amino acids that provide specificity remained unclear. In this study, a minimum set of residues in the human TrkC second immunoglobulin-like domain, which does not bind nerve growth factor (NGF), were substituted with those from human TrkA. The resulting Trk variant recruited binding of NGF equivalent to TrkA, maintained neurotrophin-3 binding equivalent to TrkC, and also bound brain-derived neurotrophin, although with lower affinity compared with TrkB. This implies that the amino acids in the second immunoglobulin-like domain that determine Trk specificity are distinct for each Trk.

Childhood sexual abuse, psychological distress, and medical use among women

OBJECTIVE

This study examined the relationships between reported history of childhood sexual abuse (CSA), psychological distress, and medical utilization among women in a health maintenance organization (HMO) setting.

METHODS

Participants were 206 women aged 20 to 63 years who were recruited from an HMO primary care clinic waiting area. Participants were classified, using screening questionnaires and the revised Symptom Checklist 90, as 1) CSA-distressed, 2) distressed only, 3) CSA only, or 4) control participants. Medical utilization rates were generated from the computerized database of the HMO for 1) nonpsychiatric outpatient, 2) psychiatric outpatient, 3) emergency room (ER), and 4) inpatient admissions.

RESULTS

CSA-distressed and distressed only groups both used significantly more nonpsychiatric outpatient visits than CSA only and control participants but were not different from one another. CSA only and control participants did not differ on nonpsychiatric outpatient utilization. CSA-distressed participants used significantly more ER visits and were more likely to visit the ER for pain-related complaints than other participants. Among CSA-distressed participants, those who met criteria for physical abuse had significantly more ER visits than those who did not. There were no differences among the four groups in inpatient utilization rates.

CONCLUSIONS

Psychological distress is associated with higher outpatient medical utilization, independent of CSA history. History of CSA with concomitant psychological distress is associated with significantly higher ER visits, particularly for those with a history of physical abuse. History of CSA without distress is not associated with elevated rates of medical utilization. Screening for psychological distress, CSA, and physical abuse may help to identify distinct subgroups with unique utilization patterns.

High resolution mapping of the binding site of TrkA for nerve growth factor and TrkC for neurotrophin-3 on the second immunoglobulin-like domain of the Trk receptors

Neurotrophic factors are important for survival and maintenance of neurons during developmental and adult stages of the vertebrate nervous system. The neurotrophins mediate their signal into the cell by specific interaction with tyrosine kinase receptors of the Trk family. The extracellular immunoglobulin-like domain of the Trk receptors adjacent to the membrane has previously been shown to be the dominant element for specific neurotrophin binding. Using computer graphics models of the human TrkA and TrkC immunoglobulin-like domains as a guide, the residues involved in binding to their respective neurotrophins were mapped by mutational analysis. TrkC primarily utilizes loop EF, between beta-strands E and F, for binding. In contrast, TrkA utilizes the EF loop as well as additional residues, the latter being prime candidates for determining the specificity of TrkA versus TrkC. When selected TrkC and TrkA mutants with reduced binding were expressed on NIH3T3 cells, neurotrophin-induced autophosphorylation was strongly reduced or absent.

Specificity determinants in neurotrophin-3 and design of nerve growth factor-based trkC agonists by changing central beta-strand bundle residues to their neurotrophin-3 analogs

Neurotrophic factors mediate their signal by binding to specific cell surface receptors of the trk family. The binding sites of neurotrophin-3 (NT-3) and nerve growth factor (NGF) to their preferred receptors trkC and trkA, respectively, were previously determined by mutational analyses. These and other studies showed that trkA can discriminate between NGF and NT-3 primarily by recognition of their N-terminal residues. The mechanism of trkC discrimination, however, remained unclear especially since the most important residue in NT-3 involved in binding to trkC, R103, is conserved in all neurotrophins. In this study residues that are part of the central beta-strand bundle of NT-3 and are not conserved among the neurotrophins were grafted onto NGF and tested for recruitment of trkC affinity. Exchange of NGF residues at positions 18, 20, 23, 29, 84, and 86 by their NT-3 counterparts resulted in NGF variants that bound to trkC, while maintaining their affinity to trkA, and were able to induce autophosphorylation and differentiation of PC12 cells expressing trkC. These variants show that the amino acid at position 23 (glycine in NGF, threonine in NT-3) is critical for trkC recognition while other residues fine tune the specificity of NT-3 for trkC. The results demonstrate the importance of nonconserved residues of the central beta-strand bundle region for the interaction of NT-3 with trkC and emphasize the different mechanism of specificity determination that is employed in the NT-3/trkC and NGF/trkA ligand/receptor pairs.

Specificity determinants in neurotrophin-3 and design of nerve growth factor-based trkC agonists by changing central beta-strand bundle residues to their neurotrophin-3 analogs

Neurotrophic factors mediate their signal by binding to specific cell surface receptors of the trk family. The binding sites of neurotrophin-3 (NT-3) and nerve growth factor (NGF) to their preferred receptors trkC and trkA, respectively, were previously determined by mutational analyses. These and other studies showed that trkA can discriminate between NGF and NT-3 primarily by recognition of their N-terminal residues. The mechanism of trkC discrimination, however, remained unclear especially since the most important residue in NT-3 involved in binding to trkC, R103, is conserved in all neurotrophins. In this study residues that are part of the central beta-strand bundle of NT-3 and are not conserved among the neurotrophins were grafted onto NGF and tested for recruitment of trkC affinity. Exchange of NGF residues at positions 18, 20, 23, 29, 84, and 86 by their NT-3 counterparts resulted in NGF variants that bound to trkC, while maintaining their affinity to trkA, and were able to induce autophosphorylation and differentiation of PC12 cells expressing trkC. These variants show that the amino acid at position 23 (glycine in NGF, threonine in NT-3) is critical for trkC recognition while other residues fine tune the specificity of NT-3 for trkC. The results demonstrate the importance of nonconserved residues of the central beta-strand bundle region for the interaction of NT-3 with trkC and emphasize the different mechanism of specificity determination that is employed in the NT-3/trkC and NGF/trkA ligand/receptor pairs.

An immunoglobulin-like domain determines the specificity of neurotrophin receptors

The neurotrophins influence survival and maintenance of vertebrate neurons in the embryonic, early post-natal and post-developmental stages of the nervous system. Binding of neurotrophins to receptors encoded by the gene family trk initiates signal transduction into the cell. trkA interacts preferably with nerve growth factor (NGF), trkB with brain-derived neurotrophic factor (BDNF) and neurotrophin-4/5 (NT-4/5) and trkC with neurotrophin-3 (NT-3). By constructing 17 different chimeras and domain deletions of the human trk receptors and analyzing their binding affinities to the neurotrophins we have shown that an immunoglobulin-like domain located adjacent to the transmembrane domain is the structural element that determines the interaction of neurotrophins with their receptors. Chimeras of trkC where this domain was exchanged for the homologous sequences from trkB or trkA gained high affinity binding to BDNF or NGF respectively, while deletion of this domain in trkC or trkA abolished binding to NT-3 or NGF respectively. This domain alone retained affinities to neurotrophins similar to the full-length receptors and when expressed on NIH 3T3 cells in fusion with the kinase domain showed neurotrophin-dependent activation.

Inhibition of allergic reactions with antibodies to IgE

Numerous clinical studies show that direct interference with the IgE response leads to a decrease or elimination of allergic symptoms. The aim of these studies was to design a therapy aimed at decreasing IgE levels in order to ameliorate atopic disease. To this end, a murine monoclonal antibody, MAE11, directed against IgE was identified, which had all the properties necessary to interfere with IgE responses, but lacked the harmful side effects of inducing receptor cross-linking. The antibody was selected on the basis of its ability to bind circulating IgE at the same site as the high-affinity receptor, thus blocking the binding of IgE to mast cells and basophils. To allow for possible chronic administration and to avoid the problems of antigenicity, MAE11 was humanized. The best of several humanized variants, version 25 (rhumAb-E25) was selected since it possessed binding affinity and biological activity comparable to MAE11. Clinical studies are underway to determine the safety and efficacy of this treatment for allergic rhinitis and asthma.

The binding site on human immunoglobulin E for its high affinity receptor

Immunoglobulin (Ig) E antibodies mediate allergic responses by binding to specific high affinity receptors, Fc epsilon RI, on mast cells and basophils. Previous studies have shown that the principal Fc epsilon RI binding site is located on the third constant domain, Fc epsilon 3, of IgE. Based on a model of the IgE Fc epsilon 3 (which is homologous to the second constant domain of IgG), homology scanning mutagenesis and replacement of individual residues were used to determine the specific amino acids of human IgE involved in binding to human Fc epsilon RI. The amino acids are localized in three loops, which form a putative ridge on the most exposed side of the Fc epsilon 3 domain of IgE and include Arg-408, Ser-411, Lys-415, Glu-452, Arg-465, and Met-469. The preponderance of charged residues suggests that IgE-Fc epsilon RI binding is mediated primarily by electrostatic interaction. Furthermore, it is possible to confer Fc epsilon RI binding to an IgG molecule by introducing these three IgE loops into the IgG C gamma 2 domain.

X-ray structure of human relaxin at 1.5 A. Comparison to insulin and implications for receptor binding determinants

The X-ray crystal structure of relaxin at 1.5 A resolution is reported for the physiologically active form of the human hormone. Relaxin is a small, two-chain polypeptide that is a member of the protein hormone family that also includes insulin and the insulin-like growth factors IGF-I and IGF-II. These hormones have biologically diverse activities but are structurally similar, sharing a distinctive pattern of cysteine and glycine residues. The predicted structural homology of relaxin to insulin is confirmed by this structural analysis; however, there are significant differences in the terminal regions of the b-chain. Although relaxin, like insulin, crystallizes as a dimer, the orientation of the molecules in the respective dimers is completely different. The region of the relaxin molecule proposed to be involved in receptor binding is part of the dimer interface, suggesting that some of the other residues contained in the dimer contact surface might be receptor binding determinants as well. The proposed receptor binding determinants for insulin likewise include residues at its dimer interface. However, because the dimer contacts of relaxin and insulin are quite different, it appears that these two structurally related hormones have evolved somewhat dissimilar mechanisms for receptor binding.

Conditions not attributable to a mental disorder: an epidemiological study of family problems

OBJECTIVE

The objective of this research was to identify and measure the differences among three groups of psychiatric outpatients: those with family problems but without mental disorders, those with both family problems and mental disorders, and those with a mental disorder but without family problems. DSM-III V code conditions (conditions not attributable to a mental disorder) other than family problems do occur, but family problems were chosen because of their importance.

METHOD

All patients admitted to an outpatient psychiatric clinic during a 2-year period were studied (N = 382). Of these, 92 had V code conditions unrelated to family problems and were excluded. Data are presented on the remaining 290 patients. Sociodemographic variables, DSM-III diagnoses, source of referral, previous and subsequent use of outpatient services, and type of family problem were examined. Patients were from a low-income population and came from three ethnic groups (white, black, and Hispanic).

RESULTS

Among whites, more men than women had family problems without mental disorders; among blacks, more women than men had family problems with and without mental disorders. Marital problems occurred most frequently in the group with family problems without mental disorders, and married subjects were more likely to have a V code condition. Professional referrals were more common than other referral sources in all three groups. However, family problems without mental disorders were more likely to occur among those who were referred by their families and had never had psychiatric treatment; patients with family problems and mental disorders were more likely to be self-referred and to have been previously treated; those with a mental disorder but without family problems were usually referred by professionals and almost always had been previously treated. There appeared to be underreporting of family problems among those with family problems and mental disorders and among black men with family problems with and without mental disorders.

CONCLUSIONS

More research is needed on the patterns of use of outpatient psychiatric services by individuals with family problems and other V code conditions.

Gauging pesticide exposure of handlers (mixer/loaders/applicators) and harvesters in California agriculture

Agricultural workers acquire pesticide exposures as a function of the properties of the product, crop, and work task. Mixer/Loaders and Applicators have greater exposure potential than other workers since concentrated formulations are handled during preparation and application of spray mixes. Exposures can be estimated using passive dosimetry and biological monitoring. Measured exposures are invariably less than estimates derived from surrogate data due to a series of conservative "worst case" assumptions and exposure estimates derived from small portions of the work day. Data have also been collected to estimate the exposure potentials of harvesters. We are establishing a set of empirical transfer factors (cm2/h) that can be used to estimate daily harvester exposure (transfer factor x dislodgeable foliar residue x hours). These estimates are important to current efforts to establish exposure-based reentry intervals to protect against acute and chronic toxicity.