Eric C. Lam

Prospective analysis of fluoroscopy duration during ERCP: critical determinants

BACKGROUND Fluoroscopy during ERCP has a linear relationship with radiation, carrying risk of exposure. OBJECTIVE To determine patient, physician, and procedural factors affecting fluoroscopy duration. DESIGN Prospective analysis of ERCPs with evaluation of patient, physician, and procedural variables. SETTING Two tertiary-care hospitals. PATIENTS Consecutive patients undergoing ERCP. INTERVENTIONS ERCP. MAIN OUTCOME MEASUREMENTS Variables associated with prolonged fluoroscopy duration. RESULTS Mean fluoroscopy time (388 ERCPs) was 6.77 minutes (95% CI, 6.15-7.39). No patient factors were found to significantly affect fluoroscopy duration. Fluoroscopy duration was significantly lower for 2 endoscopists compared with the reference endoscopist (average of 4.16 minutes less; 95% CI, -5.48 to -2.48). Multivariable analysis identified variables associated with longer fluoroscopy duration; stent insertion (+3.11 minutes; 95% CI, 1.91-4.30), lithotripsy (+5.74 minutes; 95% CI, 0.931-10.5), needle-knife sphincterotomy (+4.44 minutes; 95% CI, 2.20-6.67), biopsies (+2.11 minutes; 95% CI, 0.025-4.18), use of a guidewire (+1.55 minutes; 95% CI, 0.025-3.07), additional guidewires (+5.61 minutes; 95% CI, 2.69-8.51), and balloon catheter (+4.27 minutes; 95% CI, 3.00-5.53). Mean fluoroscopy duration when a gastroenterology fellow was involved (n = 318) was 7.05 minutes (95% CI, 6.35-7.76) compared with 5.44 minutes (95% CI, 4.26-6.63) when no fellow present (n = 70) (P < .0451). LIMITATIONS Only 2 centers; others may have different results. Not blinded; investigators may change their practice because fluoroscopy was duration studied. Irrelevance of measuring fluoroscopy duration because endoscopists using protection may not have increased radiation exposure. CONCLUSIONS In this prospective analysis, factors associated with fluoroscopy duration included endoscopists; stent insertion; lithotripsy; biopsies; use of a needle-knife, guidewire, and balloon catheter; and involvement of a gastroenterology fellow. These identified variables may help endoscopists predict which procedures are associated with prolonged fluoroscopy duration and may lead to appropriate precautions.

Factors Associated With Positive Findings From Capsule Endoscopy in Patients With Obscure Gastrointestinal Bleeding

BACKGROUND & AIMS Capsule endoscopy (CE) is used most frequently to identify causes of obscure gastrointestinal bleeding (OGIB). Identifying factors associated with the detection of lesions by CE could improve resource utilization and thereby improve patient selection for CE examination. We sought to identify clinical factors associated with positive findings from CE in patients with OGIB. METHODS We analyzed data from 698 CE procedures performed between December 2001 and April 2011 at St Pauls Hospital, Vancouver, Canada (50.3% of patients were female; mean age, 63.4 years). A positive finding was defined as a lesion that was believed to be the source of the bleeding (ulceration, mass lesion, vascular lesion, or visible blood). Univariate and multivariate logistic regression analyses were used to correlate demographic and clinical parameters with positive findings. RESULTS A lesion believed to be the cause of bleeding was identified in 42% of cases. In univariate analysis, the number of esophagogastroduodenoscopies (EGDs), the presence of connective tissue disease or diabetes with end-organ damage, Charlson comorbidity index scores, and increasing transfusion requirements were significantly associated with identification of causative pathology from CE (all P < .027). In multivariate analysis, increasing number of EGDs (odds ratio [OR], 1.17; 95% confidence interval [CI], 1.00-1.37), increasing transfusion requirements (3-9 units: OR, 1.70; 95% CI, 1.08-2.66, and ≥10 units: OR, 2.72; 95% CI, 1.69-4.37), and connective tissue disease (OR, 2.24; 95% CI, 1.14-4.41) were all significantly associated with identification of positive findings by using CE (all P < .045). CONCLUSIONS Patients with a higher number of precapsule EGDs or transfusions, or connective tissue disease, are superior candidates for analysis of OGIB by CE.

Add-On Cases in the Endoscopy Unit: Factors That Affect Volume

BACKGROUND Although most procedures in the endoscopy clinic are elective, emergency add-on cases in hospital-based endoscopy clinics are common, frequently consuming a great deal of time and resources relative to elective endoscopy procedures. OBJECTIVE To determine which specific factors correlate with the high volume of add-on emergency cases in a tertiary care, hospital-based endoscopy unit. METHODS A retrospective chart review of all gastrointestinal add-on, and electively booked cases of esophagastroduodenoscopy (EGD), colonoscopy(C) and flexible sigmoidoscopy(FS)procedures from September 2006 to May 2007, was conducted. The day of the week, month, type of procedure and physician were recorded. Emergency add-on procedures performed during the weekends were not assessed. These cases were then compared with elective cases during a similar time frame to determine differences in the aspects of add-on cases versus those that were elective. RESULTS Seven hundred twenty-one add-on cases were reviewed (mean patient age 57.4 years; 46% women) and compared with 736 elective cases (mean age 56 years; 49% women; P not significant). Of the add-on cases, 377 (52%) were EGD, 216 C (30%) and 105 (15%) were FS, with 23 combined procedures (3.2%) versus 202 (27%) EGD, 442 (60%) C and 74 (10%) FS in the elective group. Add-on cases were more likely to be EGDs than elective cases (OR 2.7; 95% CI 1.8 to 4.3; P<0.0001) and less likely to be Cs (OR 0.24; 95% CI 0.15 to 0.38; P<0.0001). There were significantly more add-on cases on Mondays (OR 1.7; 95% CI 1.0 to 2.28; P>0.03). Conversely, there were significantly fewer procedures added on Fridays (OR 0.31; 95% CI 0.16 to 0.57; P=0.0001). There were statistically fewer add-on cases in September compared with the other months that were evaluated (OR 0.31; 95% CI 0.11 to 0.78; P=0.0006). CONCLUSION With the present system of performing only emergency cases on the weekend, Monday tends to have more add-on cases. Consistent with the fact that upper gastrointestinal bleeding is the most common emergency condition, EGD is more common in add-on cases than with elective cases. Although speculative, the reasons for Friday having fewer add-on cases may be the result of a change of physician on call that day; consequently, most cases may be performed earlier in the week. For unknown reasons, fewer cases tend to be added on in September than in the other months evaluated. These data demonstrate that even in the same institution with similar patients, variability in the number of add-on cases likely is a result of many additional factors governing add-on cases, which require appropriate resource planning to ensure adequate allocation of services to ensure ideal patient care.

Who needs an endoscopic ultrasound

University of British Columbia, Vancouver, British Columbia Correspondence and reprints: Dr Eric C Lam, Division of Gastroenterology, University of British Columbia, #770 – 1190 Hornby Street, Vancouver, British Columbia V6Z 2K5. Telephone 604-688-6332 ext 224, fax 604-689-2004, e-mail ecslam@shaw.ca Endoscopic ultrasound (EUS) is a technique that has seen increasing interest in the past decade. It has enabled the endosonographer to visualize details of anatomy and pathology not usually available to most gastroenterologists or even radiologists. The list of indications for EUS is growing and this has forced gastroenterologists to ‘think outside the lumen’ about the possibilities. Because EUS in Canada currently is limited to a few centres, EUS may not be foremost in the minds of gastroenterologists as a useful diagnostic and therapeutic tool. Before outlining the evidence for the current indications for an EUS, it is important to understand what is available. Figure 1 shows the two scanning methods available. With radial EUS, the generated imaging plane is perpendicular to the long axis of the endoscope. This provides a 270° or 360° cross-sectional view of the mediastinum and rectum, and an overall view of the upper retroperitoneum. It is unsuitable for fine needle aspiration biopsy. With linear EUS, the imaging plane is generated in parallel to the long axis of the endoscope. Although this method provides a limited wedgeshaped scanning plane, the entire trajectory of a fine needle aspiration biopsy needle can be visualized and is therefore the method of choice to biopsy lesions. Another radial scanning technique is the miniprobe. These miniprobes measure 2.5 mm in diameter and can be advanced down a standard gastroscope. They are generally higher frequency probes that provide more detailed circumferential images of the bowel wall layers but havelimited depth of penetration. They are ideal for intramural lesions of the gastrointestinal tract. The combined ability to image the layers of the bowel wall and structures adjacent to it has resulted in a powerful tool that has influenced clinical decision making. Common indications for EUS are listed in Table 1. The nongastrointestinal indications, such as lung cancer staging, are not discussed in the present article.

Pancreatic Neuroendocrine Tumours: Established Role of Endoscopic Ultrasound in High-Risk Populations

Pancreatic neuroendocrine tumours (PNETs) are rare tumours of the pancreas that arise from cells that produce hormonally active substances. Insulin and gastrin are the most common hormone-producing tumours that are associated with symptoms. A proportion of these tumours can develop without symptoms and are incidentally found at the time of abdominal imaging, or only become symptomatic when the tumour is large. Certain genetic syndromes are associated with a high prevalence of PNETs. Multiple endocrine neoplasm type 1 (MEN1) is the most common genetic syndrome associated with PNETs. The tumours can be multifocal, ranging in size and function. Often, MEN1 patients have a high prevalence of other tumours, such as adrenal and pituitary tumours. In this issue of The Canadian Journal of Gastroenterology, Alsohaibani et al ( pages 817–820) report a retrospective study of 14 PNET patients who underwent preoperative assessment with endoscopic ultrasound (EUS). They also discuss the impact that EUS had on surgical decision-making. The initial workup for nearly all patients consisted of computed tomography (CT) scanning and EUS, while others had other preoperative workups, such as magnetic resonance imaging and octreotide scintigraphy. EUS detected PNETs in all 14 cases (100%), whereas the CT detection rate was 77%. Furthermore, among those with multifocal PNETs, the extent of pancreatic involvement was underestimated by CT imaging in three cases. As a result, the decision to undergo surgery was changed in 36% of patients and the extent of surgery required was changed in 50% of patients. There are drawbacks to the study by Alsohaibani et al. No inferences can be made about the efficacy of EUS in impacting the role of surgery because of the small numbers of patients and the retrospective, descriptive study design. However, because PNETs are rare (estimates of one per 100,000 population), to accumulate more cases would require years, during which time imaging technology and surgical techniques would most certainly change. A multicentre review would be the best way to investigate whether EUS truly impacts surgery. Although the authors state that there are drawbacks to their retrospective case series, the results speak to the detection limits of existing imaging techniques. Many PNETs are vascular lesions and often enhance to the same degree as adjacent pancreatic tissue, thereby evading detection by contrast CT. Although all PNETs have somatostatin receptors, the elusive tumours are small and there is variable binding of somatostatin in them. Therefore, current indium-based scintigraphy is unable to detect the small lesions with variable somatostatin binding due to a lack of resolution. More promising data are emerging on radiopharmaceuticals with variable affinity somatostatin receptor analogues (1). Finally, magnetic resonance imaging has a better sensitivity than CT scanning, but small lesions can also be missed by this modality. Only EUS, which has an axial resolution of 0.4 mm at 7.5 MHz, can reliably detect these small lesions and provide a cytological diagnosis by fine needle aspiration (2). Is EUS an essential modality in all PNETs, or all pancreatic masses, for that matter? Risk-stratifying patients would determine which patients would benefit the most from EUS. Patients with MEN1 are distinctly different from those who present with no such history. Indeed, in the study by Alsohaibani et al, all patients who were found to have multifocal disease had MEN1. Some authorities have suggested that asymptomatic MEN1 patients should be screened to detect multifocal disease (3). Because not all MEN1-related PNETs are functional tumours, detection before they become symptomatic is key. As for the PNETs not associated with MEN1 or other genetic syndromes, this group is usually detected as an incidental finding on cross-sectional imaging. Unless these tumours undergo cystic degeneration or cause compressive biliary symptoms, they are essentially asymptomatic. There is an increasing trend of detecting nonfunctional tumours. This group of patients will become more important in the future (4). With the current state of cross-sectional imaging, a high index of suspicion is required to make this diagnosis with EUS providing the cytological confirmation by fine needle aspiration. There is a well-established role for EUS in pancreatic masses. Cross-sectional imaging will still be the test of first contact and is needed to assess distant metastatic disease. However, the article by Alsohaibani et al has reiterated the essential role of EUS in providing a more detailed evaluation of pancreatic masses.