J Gastroenterol DOI 10.1007/s00535-015-1069-9
ORIGINAL ARTICLE—ALIMENTARY TRACT
Role of urgent contrast-enhanced multidetector computed tomography for acute lower gastrointestinal bleeding in patients undergoing early colonoscopy Naoyoshi Nagata1 • Ryota Niikura1 • Tomonori Aoki1 • Shiori Moriyasu1 • Toshiyuki Sakurai1 • Takuro Shimbo2 • Masafumi Shinozaki3 • Katsunori Sekine1 Hidetaka Okubo1 • Kazuhiro Watanabe1 • Chizu Yokoi1 • Mikio Yanase1 • Junichi Akiyama1 • Naomi Uemura4
•
Received: 13 January 2015 / Accepted: 15 March 2015 Ó Springer Japan 2015
Abstract Background The clinical significance of performing computed tomography (CT) for acute lower gastrointestinal bleeding (LGIB) remains unknown. This study aimed to evaluate the role of urgent CT in acute LGIB settings. Methods The cohort comprised 223 patients emergently hospitalized for LGIB who underwent early colonoscopy within 24 h of arriving at the hospital, including 126 who underwent CT within 3 h of arrival. We compared the bleeding source rate between two strategies: early colonoscopy following urgent CT or early colonoscopy alone. Results No significant differences in age, sex, comorbidities, vital signs, or laboratory data were observed between the strategies. The detection rate was higher with colonoscopy following CT for vascular lesions (35.7 vs. 20.6 %, p = 0.01), leading to more endoscopic therapies (34.9 vs. 13.4 %, p \ 0.01). Of the 126 who underwent colonoscopy following CT, 26 (20.6 %) had extravasation and 34 (27.0 %) had nonvascular findings. The sensitivity and specificity of CT extravasation and nonvascular & Naoyoshi Nagata [email protected] 1
Department of Gastroenterology and Hepatology, National Center for Global Health and Medicine (NCGM), 1-21-1 Toyama, Shinjuku-ku, Tokyo 162-8655, Japan
2
Department of Clinical Research and Informatics, International Clinical Research Center, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan
3
Department of Diagnostic Radiology, National Center for Global Health and Medicine, Tokyo, Japan
4
Department of Gastroenterology and Hepatology, National Center for Global Health and Medicine, Kohnodai Hospital, Chiba, Japan
findings for predicting vascular lesions and inflammation or tumors were 37.8 and 88.9 and 81.3 and 80.9 %, respectively. A high j agreement (0.83, p \ 0.01) for active bleeding locations was found between CT and subsequent colonoscopy. There were no cases of contrast-induced nephropathy after 1 week of CT. Conclusions Urgent CT before colonoscopy had about 15 % additional value for detecting vascular lesion compared to colonoscopy alone and thus enabled subsequent endoscopic therapies. Contrast-enhanced CT in acute LGIB settings was safe and correctly identified the presence and location of active bleeding, as well as severe inflammation or tumor stenosis, facilitating decision making. Keywords Multidetector computed tomography (MDCT) angiography Urgent colonoscopy Acute lower gastrointestinal hemorrhage Colonic diverticular bleeding
Introduction Among the diagnostic strategies for the initial management of overt lower gastrointestinal bleeding (LGIB), colonoscopy is optimal for confirming the source of bleeding [1, 2]. In particular, early colonoscopy within 24 h of admission, rather than elective colonoscopy, leads to better diagnostic and therapeutic opportunities, which decreases the need for surgical intervention, rate of rebleeding, and length of hospital stay [3, 4]. However, compared with radiographic interventions, early colonoscopy requires more colon preparation and experienced staff, as well as access to endoscopy facilities [1]. Contrast-enhanced multidetector computed tomography (MDCT), on the other hand, which is readily available in many hospitals [5], has several advantages: it can be
123
J Gastroenterol
rapidly performed, it does not require bowel preparation, and it has the potential to identify bleeding sources to guide optimal interventions. MDCT may also provide information on the underlying etiologies of vascular and nonvascular diseases such as inflammatory or neoplastic lesions [6]. Thus, MDCT is helpful for determining appropriate therapeutic approaches while also reducing the rate of unnecessary examinations. Data on the accuracy of MDCT in cases of LGIB are available from small case series studies (n \ 52) [7–9], but whether or not incorporating MDCT will increase the rate of detecting bleeding sources and improve subsequent clinical outcomes remains unknown. In addition, prior studies on the gold standard diagnosis have produced unclear findings or were based on elective colonoscopy without preparation [7–9], which can influence the detection rate of bleeding sources on colonoscopy. Against this background, we conducted a comparative study of a relatively large cohort of patients hospitalized for acute LGIB, who underwent one of two strategies: early colonoscopy following urgent MDCT or early colonoscopy alone. The specific objectives of this study were (1) to determine the added value of urgent MDCT in the workup of patients with LGIB, (2) to identify the accuracy of MDCT findings for predicting colonoscopic diagnosis, and (3) to determine the short-term safety of urgent MDCT.
Fig. 1 Study flow
123
Materials and methods Study design, setting, and participants This study was approved by the institutional review board (no. 1579) of the National Center for Global Health and Medicine (NCGM). We retrospectively studied 404 patients emergently admitted for acute, continuous, or frequent overt LGIB who underwent colonoscopy at NCGM between August 2008 and December 2013 (Fig. 1). All patients had outpatient onset LGIB. The NCGM has 900 beds and is one of the largest emergency hospitals in the Tokyo metropolitan area. After excluding patients with upper gastrointestinal bleeding (n = 3) identified on upper endoscopy after colonoscopy, those who had undergone colonoscopy with over 24 h of hospitalization (n = 140), those who had undergone MDCT without contrast (n = 16), those with a history of colonic resection (n = 9), and those who had undergone barium impaction therapy (n = 27) in a randomized controlled trial (approval no. 765), the remaining 223 patients were included in the analysis (Fig. 1). Clinical factors Past history, comorbidities, medication use, physical examination findings, initial vital signs, and emergency room
J Gastroenterol
laboratory data were assessed. The use of nonsteroidal antiinflammatory drugs (NSAIDs), low-dose aspirin (81 mg buffered aspirin or 100 mg enteric-coated aspirin), non-aspirin antiplatelet drugs (clopidogrel, ticlopidine, cilostazol, and dipyridamole), or warfarin was defined as oral administration within 1 month before admission. Serum creatinine on the day of pre-contrast MDCT exposure and 1 week after MDCT was collected. Contrast-induced nephropathy was defined as an increase in creatinine C0.5 mg/dl before and after contrast medium exposure [10]. MDCT procedures All MDCT scans were done at our center and could be performed within 3 h of arriving at the emergency room because the CT machine was situated in a medical examination room adjacent to the emergency department. A total of 90 ml iopamidol (Oypalomin 300; Konica Minolta, Tokyo, Japan) was power-injected intravenously. Patients were assessed with a 64-data acquisition system multidetector raw CT scanner (Aquilion CX; Toshiba Medical Systems, Japan) while in the supine position. All CT examinations were performed using helical scanning
Fig. 2 Contrast-enhanced multidetector computed tomography (MDCT) and colonoscopy findings. a Vascular findings on MDCT showing extravasation and pooling of contrast medium into the rectum (axial image). A case of rectal ulcer. b Extravasation of contrast medium into the colonic lumen (coronal image). A case of
with the following parameters: 64 9 0.5 mm collimation, 120 kV, auto exposure control set with standard deviation 10; beam pitch 0.83 (table feed per rotation, 25.6 mm; collimation beam width, 32 mm), 0.5-s exposure time per rotation, 512 9 512 matrix, and 350–500mm field of view. All images were reconstructed using a standard reconstruction algorithm. MDCT images were interpreted by two expert radiologists (C15 years’ experience). Detection of the bleeding source on MDCT was defined as follows: (1) visualization of the extravasation of contrast medium into the intestinal wall (Fig. 2a, b), which is suggestive of vascular findings; (2) visualization of intestinal wall thickening (Fig. 2c), edema, mass lesion (Fig. 2d), or stenosis (Fig. 2d), which are suggestive of nonvascular findings. Colonoscopy procedures An electronic high-resolution video endoscope (model CFH260; Olympus Optical, Tokyo, Japan) was used to diagnose bleeding sources. Intestinal lavage for colonoscopy was performed using sodium picosulfate on the day before the assessment and 2 l polyethylene glycol solution
diverticular bleeding. c Intestinal wall thickening and edema (coronal image). A case of ulcerative colitis. d Intestinal wall thickening, mass lesion, and stenosis (axial image). A case of colonic cancer. e Active bleeding in rectal ulcerous mucosa. f Visible vessel in the colonic diverticulum
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J Gastroenterol
on the day of assessment [11]. Patients who were unable to take an oral preparation were given an enema. If colonoscopy showed insufficient bowel preparation, we used a water-jet scope (Olympus Flushing Pump; Olympus Optical, Tokyo, Japan) because 2 l preparation may be insufficient for adequately clearing the bowel in the acute care setting [12]. Before colonoscopy, upper gastrointestinal sources of bleeding were ruled out in all patients by nasogastric lavage and/or on upper endoscopy. The timing of colonoscopy differed according to the attending physician’s decision or the time of visiting our institution. One physician may have performed early colonoscopy when the bleeding persisted, whereas another may have tended to wait and perform elective colonoscopy after spontaneous cessation of bleeding, especially when LGIB patients visited at night or on the weekend. However, the timing of colonoscopy is important because it can significantly influence the detection rate of bleeding sources on colonoscopy [12]. Therefore, we included patients who underwent early colonoscopy within 24 h of arriving at the hospital [13]. When the bleeding source could not be identified on colonoscopy, repeated upper endoscopy, capsule endoscopy, and/or double-balloon endoscopy were attempted whenever possible. The gold standard for detecting bleeding sources is based on colonoscopy and defined as follows. (1) Vascular lesions included active bleeding (Fig. 2e), an adherent clot, or visible vessel (Fig. 2f) [4, 14]. A vascular lesion was identified in diverticular bleeding, radiation telangiectasia, angioectasia, rectal ulcer, hemorrhoid, post-polypectomy/ endoscopic mucosal resection, and small bowel bleeding. (2) A nonvascular lesion was defined as inflammation or tumor such as colitis, inflammatory bowel disease, and colorectal cancer. Patients in whom the bleeding source was identified received endoscopic treatment such as clipping or endoscopic ligation. At our institution, angiography or surgery is indicated for patients with persistent or severe bleeding who do not respond to endoscopic treatment. The diagnostic criteria of diverticular bleeding are divided into those concerning definite and presumptive bleeding [4, 14]. A definite diagnosis is based on colonoscopic visualization of a colonic diverticulum with vascular lesions such as active bleeding, a visible vessel, or an adherent clot [4, 14]. On the other hand, a presumptive diagnosis is based on the following criteria: (1) fresh blood localized to the colonic diverticula in the presence of a potential bleeding source on total colonoscopy, (2) bright red blood in the rectum confirmed by objective color testing and colonoscopy demonstrating a single potential bleeding source in the colon complemented by negative upper endoscopy or negative capsule endoscopy, or (3) negative nasogastric lavage findings [4, 14].
123
Outcomes Clinical outcomes were the detection rate of the bleeding source, need for endoscopic therapies, need for transfusion, and rebleeding. Units of packed red blood cells were evaluated after colonoscopy. During hospitalization, blood transfusion was indicated for patients when the hemoglobin level fell below 7.0 g/dl, or below 8.0 g/dl in those with unstable vital signs. Rebleeding was defined as significant fresh bloody or wine-colored stool accompanied by unstable vital signs, systolic blood pressure B90 mmHg or pulse C110 beats/min, and non-response to C2 units of transfused blood after colonoscopy [15]. In such cases, colonoscopy was performed in addition to anoscopy or MDCT to evaluate the bleeding source whenever possible. Statistical analysis We compared the baseline characteristics and clinical outcomes between two strategies: early colonoscopy following MDCT or early colonoscopy alone, using the Mann-Whitney U test or Pearson’s chi-squared test. Of the 126 patients who underwent early colonoscopy following MDCT, we identified the accuracy of MDCT findings (extravasation or nonvascular findings) for predicting colonoscopic diagnosis (vascular lesion or inflammation or tumor). We calculated the sensitivity, specificity, and positive and negative likelihood ratios. The interobserver agreement for colonic location between MDCT and colonoscopy was measured using kappa statistics. In addition, interobserver agreement of CT extravasation between two experts was analyzed. j [ 0.80 denoted excellent agreement, [0.60–0.80 good, [0.40–0.60 moderate, [0.20–0.40 fair, and B0.20 poor [16]. To identify the predictors for extravasation identification on MDCT, we conducted multiple logistic regression analysis using the backward elimination method on factors found to be significant (p \ 0.10) in univariate analysis, and we calculated the estimated odds ratios (OR) and 95 % confidence intervals (CI). Wilcoxon matched-pairs signedranks test was used to identify the change in creatinine levels before and after the MDCT. All statistical analysis was performed using Stata version 13 software (StataCorp, College Station, TX), and p \ 0.05 was considered significant.
Results Patients The baseline characteristics of the 223 patients are shown in Table 1: 126 underwent early colonoscopy following
J Gastroenterol Table 1 Baseline characteristics of the study cohort on examination in the emergency room (n = 223)
Mean age (years) Age C 65 years Sex, male
Early colonoscopy following urgent CT (n = 126)
Early colonoscopy alone (n = 97)
p
68.3 ± 16.5
67.7 ± 16.5
0.75
82 (65.1)
60 (61.9)
71 (56.4)
62 (63.9)
History of diverticular bleeding
37 (29.4)
25 (25.8)
0.55
BMIa
22.6 ± 4.3
22.7 ± 3.6
0.95
62 (49.2) 19 (15.1)
56 (57.7) 18 (18.6)
0.34 0.49
Comorbidity Hypertension Diabetes mellitus Cerebrovascular disease
10 (7.9)
8 (8.3)
0.93
Coronary artery disease
24 (19.1)
15 (15.5)
0.49
Chronic obstructive pulmonary disease
2 (1.6)
2 (2.1)
0.79
Chronic kidney disease
6 (4.8)
1 (1.0)
0.11
Chronic liver disease
7 (5.6)
8 (8.3)
0.43
NSAIDs
33 (26.2)
13 (13.4)
0.02
Low-dose aspirin (B100 mg)
29 (23.0)
26 (26.8)
0.52
Non-aspirin antiplatelets
26 (20.6)
10 (10.3)
0.04
Anticoagulants
7 (5.6)
4 (4.1)
0.62
Medication
Physical examination Syncope
11 (8.8)
2 (5.3)
0.48
Abdominal pain
25 (19.8)
2 (5.3)
0.03
Systolic blood pressure (mmHg) Heart rate (beats/min)
122.9 ± 22.9 86.0 ± 16.4
124.88 ± 20.8 82.2 ± 15.2
0.38 0.11
Hemodynamic instabilityb
5 (4.0)
1 (1.0)
0.18
Laboratory data Hemoglobin (g/l)
10.9 ± 3.0
11.5 ± 2.5
0.18
Platelets (103/ll)
21.1 ± 9.3
19.4 ± 5.6
0.36
Blood urea nitrogen (mg/dl)
20.5 ± 12.5
18.7 ± 11.3
0.16
Creatinine (mg/dl)
1.09 ± 1.08
1.00 ± 0.59
0.61
C-reactive protein (mg/dl)
1.32 ± 3.1
1.25 ± 4.2
0.68
Use of enema
7 (5.3 %)
3 (3.0)
0.40
Use of a water-jet scope
30 (19.2)
24 (19.8)
0.90
Failure rate in reaching the cecum
3 (2.3)
2 (2.0)
0.88
Preparation and cecal intubation
Bold values indicate a statistically significant difference with a p value less than 0.05 Values in parentheses show percentages. Values presented with a ± symbol show the mean ± SD. Some patients had more than one comorbidity BMI body mass index, NSAIDs nonsteroidal antiinflammatory drugs, MDCT multidetector contrast-enhanced computed tomography a
BMI data were collected from 110 patients with MDCT and 71 patients without MDCT
b
Hemodynamic instability was defined as initial systolic blood pressure B115 mmHg, initial heart rate C100/min, and the presence of syncope
urgent MDCT and 97 underwent early colonoscopy alone. No significant differences were observed in theage, sex, past history, all comorbidities, initial vital signs, laboratory data, enema, water-jet scope usage, or cecal intubation rate
between the two strategies. The use of NSAIDs and nonaspirin antiplatelets as well as abdominal pain were significantly higher in the MDCT group. Bleeding sources of the lower GI tract are shown in Table 2.
123
J Gastroenterol Table 2 Source of lower gastrointestinal bleeding on colonoscopy with pathology (n = 223) Early colonoscopy following urgent MDCT (n = 126)
Early colonoscopy alone (n = 97)
Diverticular bleeding
77 (61.1)
63 (65.0)
Definitive/presumptive diverticular bleeding
35 (45.5)/22(54.5)
11 (17.5)/52 (82.5)
p
0.56
ORIGINAL ARTICLE—ALIMENTARY TRACT
Role of urgent contrast-enhanced multidetector computed tomography for acute lower gastrointestinal bleeding in patients undergoing early colonoscopy Naoyoshi Nagata1 • Ryota Niikura1 • Tomonori Aoki1 • Shiori Moriyasu1 • Toshiyuki Sakurai1 • Takuro Shimbo2 • Masafumi Shinozaki3 • Katsunori Sekine1 Hidetaka Okubo1 • Kazuhiro Watanabe1 • Chizu Yokoi1 • Mikio Yanase1 • Junichi Akiyama1 • Naomi Uemura4
•
Received: 13 January 2015 / Accepted: 15 March 2015 Ó Springer Japan 2015
Abstract Background The clinical significance of performing computed tomography (CT) for acute lower gastrointestinal bleeding (LGIB) remains unknown. This study aimed to evaluate the role of urgent CT in acute LGIB settings. Methods The cohort comprised 223 patients emergently hospitalized for LGIB who underwent early colonoscopy within 24 h of arriving at the hospital, including 126 who underwent CT within 3 h of arrival. We compared the bleeding source rate between two strategies: early colonoscopy following urgent CT or early colonoscopy alone. Results No significant differences in age, sex, comorbidities, vital signs, or laboratory data were observed between the strategies. The detection rate was higher with colonoscopy following CT for vascular lesions (35.7 vs. 20.6 %, p = 0.01), leading to more endoscopic therapies (34.9 vs. 13.4 %, p \ 0.01). Of the 126 who underwent colonoscopy following CT, 26 (20.6 %) had extravasation and 34 (27.0 %) had nonvascular findings. The sensitivity and specificity of CT extravasation and nonvascular & Naoyoshi Nagata [email protected] 1
Department of Gastroenterology and Hepatology, National Center for Global Health and Medicine (NCGM), 1-21-1 Toyama, Shinjuku-ku, Tokyo 162-8655, Japan
2
Department of Clinical Research and Informatics, International Clinical Research Center, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan
3
Department of Diagnostic Radiology, National Center for Global Health and Medicine, Tokyo, Japan
4
Department of Gastroenterology and Hepatology, National Center for Global Health and Medicine, Kohnodai Hospital, Chiba, Japan
findings for predicting vascular lesions and inflammation or tumors were 37.8 and 88.9 and 81.3 and 80.9 %, respectively. A high j agreement (0.83, p \ 0.01) for active bleeding locations was found between CT and subsequent colonoscopy. There were no cases of contrast-induced nephropathy after 1 week of CT. Conclusions Urgent CT before colonoscopy had about 15 % additional value for detecting vascular lesion compared to colonoscopy alone and thus enabled subsequent endoscopic therapies. Contrast-enhanced CT in acute LGIB settings was safe and correctly identified the presence and location of active bleeding, as well as severe inflammation or tumor stenosis, facilitating decision making. Keywords Multidetector computed tomography (MDCT) angiography Urgent colonoscopy Acute lower gastrointestinal hemorrhage Colonic diverticular bleeding
Introduction Among the diagnostic strategies for the initial management of overt lower gastrointestinal bleeding (LGIB), colonoscopy is optimal for confirming the source of bleeding [1, 2]. In particular, early colonoscopy within 24 h of admission, rather than elective colonoscopy, leads to better diagnostic and therapeutic opportunities, which decreases the need for surgical intervention, rate of rebleeding, and length of hospital stay [3, 4]. However, compared with radiographic interventions, early colonoscopy requires more colon preparation and experienced staff, as well as access to endoscopy facilities [1]. Contrast-enhanced multidetector computed tomography (MDCT), on the other hand, which is readily available in many hospitals [5], has several advantages: it can be
123
J Gastroenterol
rapidly performed, it does not require bowel preparation, and it has the potential to identify bleeding sources to guide optimal interventions. MDCT may also provide information on the underlying etiologies of vascular and nonvascular diseases such as inflammatory or neoplastic lesions [6]. Thus, MDCT is helpful for determining appropriate therapeutic approaches while also reducing the rate of unnecessary examinations. Data on the accuracy of MDCT in cases of LGIB are available from small case series studies (n \ 52) [7–9], but whether or not incorporating MDCT will increase the rate of detecting bleeding sources and improve subsequent clinical outcomes remains unknown. In addition, prior studies on the gold standard diagnosis have produced unclear findings or were based on elective colonoscopy without preparation [7–9], which can influence the detection rate of bleeding sources on colonoscopy. Against this background, we conducted a comparative study of a relatively large cohort of patients hospitalized for acute LGIB, who underwent one of two strategies: early colonoscopy following urgent MDCT or early colonoscopy alone. The specific objectives of this study were (1) to determine the added value of urgent MDCT in the workup of patients with LGIB, (2) to identify the accuracy of MDCT findings for predicting colonoscopic diagnosis, and (3) to determine the short-term safety of urgent MDCT.
Fig. 1 Study flow
123
Materials and methods Study design, setting, and participants This study was approved by the institutional review board (no. 1579) of the National Center for Global Health and Medicine (NCGM). We retrospectively studied 404 patients emergently admitted for acute, continuous, or frequent overt LGIB who underwent colonoscopy at NCGM between August 2008 and December 2013 (Fig. 1). All patients had outpatient onset LGIB. The NCGM has 900 beds and is one of the largest emergency hospitals in the Tokyo metropolitan area. After excluding patients with upper gastrointestinal bleeding (n = 3) identified on upper endoscopy after colonoscopy, those who had undergone colonoscopy with over 24 h of hospitalization (n = 140), those who had undergone MDCT without contrast (n = 16), those with a history of colonic resection (n = 9), and those who had undergone barium impaction therapy (n = 27) in a randomized controlled trial (approval no. 765), the remaining 223 patients were included in the analysis (Fig. 1). Clinical factors Past history, comorbidities, medication use, physical examination findings, initial vital signs, and emergency room
J Gastroenterol
laboratory data were assessed. The use of nonsteroidal antiinflammatory drugs (NSAIDs), low-dose aspirin (81 mg buffered aspirin or 100 mg enteric-coated aspirin), non-aspirin antiplatelet drugs (clopidogrel, ticlopidine, cilostazol, and dipyridamole), or warfarin was defined as oral administration within 1 month before admission. Serum creatinine on the day of pre-contrast MDCT exposure and 1 week after MDCT was collected. Contrast-induced nephropathy was defined as an increase in creatinine C0.5 mg/dl before and after contrast medium exposure [10]. MDCT procedures All MDCT scans were done at our center and could be performed within 3 h of arriving at the emergency room because the CT machine was situated in a medical examination room adjacent to the emergency department. A total of 90 ml iopamidol (Oypalomin 300; Konica Minolta, Tokyo, Japan) was power-injected intravenously. Patients were assessed with a 64-data acquisition system multidetector raw CT scanner (Aquilion CX; Toshiba Medical Systems, Japan) while in the supine position. All CT examinations were performed using helical scanning
Fig. 2 Contrast-enhanced multidetector computed tomography (MDCT) and colonoscopy findings. a Vascular findings on MDCT showing extravasation and pooling of contrast medium into the rectum (axial image). A case of rectal ulcer. b Extravasation of contrast medium into the colonic lumen (coronal image). A case of
with the following parameters: 64 9 0.5 mm collimation, 120 kV, auto exposure control set with standard deviation 10; beam pitch 0.83 (table feed per rotation, 25.6 mm; collimation beam width, 32 mm), 0.5-s exposure time per rotation, 512 9 512 matrix, and 350–500mm field of view. All images were reconstructed using a standard reconstruction algorithm. MDCT images were interpreted by two expert radiologists (C15 years’ experience). Detection of the bleeding source on MDCT was defined as follows: (1) visualization of the extravasation of contrast medium into the intestinal wall (Fig. 2a, b), which is suggestive of vascular findings; (2) visualization of intestinal wall thickening (Fig. 2c), edema, mass lesion (Fig. 2d), or stenosis (Fig. 2d), which are suggestive of nonvascular findings. Colonoscopy procedures An electronic high-resolution video endoscope (model CFH260; Olympus Optical, Tokyo, Japan) was used to diagnose bleeding sources. Intestinal lavage for colonoscopy was performed using sodium picosulfate on the day before the assessment and 2 l polyethylene glycol solution
diverticular bleeding. c Intestinal wall thickening and edema (coronal image). A case of ulcerative colitis. d Intestinal wall thickening, mass lesion, and stenosis (axial image). A case of colonic cancer. e Active bleeding in rectal ulcerous mucosa. f Visible vessel in the colonic diverticulum
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J Gastroenterol
on the day of assessment [11]. Patients who were unable to take an oral preparation were given an enema. If colonoscopy showed insufficient bowel preparation, we used a water-jet scope (Olympus Flushing Pump; Olympus Optical, Tokyo, Japan) because 2 l preparation may be insufficient for adequately clearing the bowel in the acute care setting [12]. Before colonoscopy, upper gastrointestinal sources of bleeding were ruled out in all patients by nasogastric lavage and/or on upper endoscopy. The timing of colonoscopy differed according to the attending physician’s decision or the time of visiting our institution. One physician may have performed early colonoscopy when the bleeding persisted, whereas another may have tended to wait and perform elective colonoscopy after spontaneous cessation of bleeding, especially when LGIB patients visited at night or on the weekend. However, the timing of colonoscopy is important because it can significantly influence the detection rate of bleeding sources on colonoscopy [12]. Therefore, we included patients who underwent early colonoscopy within 24 h of arriving at the hospital [13]. When the bleeding source could not be identified on colonoscopy, repeated upper endoscopy, capsule endoscopy, and/or double-balloon endoscopy were attempted whenever possible. The gold standard for detecting bleeding sources is based on colonoscopy and defined as follows. (1) Vascular lesions included active bleeding (Fig. 2e), an adherent clot, or visible vessel (Fig. 2f) [4, 14]. A vascular lesion was identified in diverticular bleeding, radiation telangiectasia, angioectasia, rectal ulcer, hemorrhoid, post-polypectomy/ endoscopic mucosal resection, and small bowel bleeding. (2) A nonvascular lesion was defined as inflammation or tumor such as colitis, inflammatory bowel disease, and colorectal cancer. Patients in whom the bleeding source was identified received endoscopic treatment such as clipping or endoscopic ligation. At our institution, angiography or surgery is indicated for patients with persistent or severe bleeding who do not respond to endoscopic treatment. The diagnostic criteria of diverticular bleeding are divided into those concerning definite and presumptive bleeding [4, 14]. A definite diagnosis is based on colonoscopic visualization of a colonic diverticulum with vascular lesions such as active bleeding, a visible vessel, or an adherent clot [4, 14]. On the other hand, a presumptive diagnosis is based on the following criteria: (1) fresh blood localized to the colonic diverticula in the presence of a potential bleeding source on total colonoscopy, (2) bright red blood in the rectum confirmed by objective color testing and colonoscopy demonstrating a single potential bleeding source in the colon complemented by negative upper endoscopy or negative capsule endoscopy, or (3) negative nasogastric lavage findings [4, 14].
123
Outcomes Clinical outcomes were the detection rate of the bleeding source, need for endoscopic therapies, need for transfusion, and rebleeding. Units of packed red blood cells were evaluated after colonoscopy. During hospitalization, blood transfusion was indicated for patients when the hemoglobin level fell below 7.0 g/dl, or below 8.0 g/dl in those with unstable vital signs. Rebleeding was defined as significant fresh bloody or wine-colored stool accompanied by unstable vital signs, systolic blood pressure B90 mmHg or pulse C110 beats/min, and non-response to C2 units of transfused blood after colonoscopy [15]. In such cases, colonoscopy was performed in addition to anoscopy or MDCT to evaluate the bleeding source whenever possible. Statistical analysis We compared the baseline characteristics and clinical outcomes between two strategies: early colonoscopy following MDCT or early colonoscopy alone, using the Mann-Whitney U test or Pearson’s chi-squared test. Of the 126 patients who underwent early colonoscopy following MDCT, we identified the accuracy of MDCT findings (extravasation or nonvascular findings) for predicting colonoscopic diagnosis (vascular lesion or inflammation or tumor). We calculated the sensitivity, specificity, and positive and negative likelihood ratios. The interobserver agreement for colonic location between MDCT and colonoscopy was measured using kappa statistics. In addition, interobserver agreement of CT extravasation between two experts was analyzed. j [ 0.80 denoted excellent agreement, [0.60–0.80 good, [0.40–0.60 moderate, [0.20–0.40 fair, and B0.20 poor [16]. To identify the predictors for extravasation identification on MDCT, we conducted multiple logistic regression analysis using the backward elimination method on factors found to be significant (p \ 0.10) in univariate analysis, and we calculated the estimated odds ratios (OR) and 95 % confidence intervals (CI). Wilcoxon matched-pairs signedranks test was used to identify the change in creatinine levels before and after the MDCT. All statistical analysis was performed using Stata version 13 software (StataCorp, College Station, TX), and p \ 0.05 was considered significant.
Results Patients The baseline characteristics of the 223 patients are shown in Table 1: 126 underwent early colonoscopy following
J Gastroenterol Table 1 Baseline characteristics of the study cohort on examination in the emergency room (n = 223)
Mean age (years) Age C 65 years Sex, male
Early colonoscopy following urgent CT (n = 126)
Early colonoscopy alone (n = 97)
p
68.3 ± 16.5
67.7 ± 16.5
0.75
82 (65.1)
60 (61.9)
71 (56.4)
62 (63.9)
History of diverticular bleeding
37 (29.4)
25 (25.8)
0.55
BMIa
22.6 ± 4.3
22.7 ± 3.6
0.95
62 (49.2) 19 (15.1)
56 (57.7) 18 (18.6)
0.34 0.49
Comorbidity Hypertension Diabetes mellitus Cerebrovascular disease
10 (7.9)
8 (8.3)
0.93
Coronary artery disease
24 (19.1)
15 (15.5)
0.49
Chronic obstructive pulmonary disease
2 (1.6)
2 (2.1)
0.79
Chronic kidney disease
6 (4.8)
1 (1.0)
0.11
Chronic liver disease
7 (5.6)
8 (8.3)
0.43
NSAIDs
33 (26.2)
13 (13.4)
0.02
Low-dose aspirin (B100 mg)
29 (23.0)
26 (26.8)
0.52
Non-aspirin antiplatelets
26 (20.6)
10 (10.3)
0.04
Anticoagulants
7 (5.6)
4 (4.1)
0.62
Medication
Physical examination Syncope
11 (8.8)
2 (5.3)
0.48
Abdominal pain
25 (19.8)
2 (5.3)
0.03
Systolic blood pressure (mmHg) Heart rate (beats/min)
122.9 ± 22.9 86.0 ± 16.4
124.88 ± 20.8 82.2 ± 15.2
0.38 0.11
Hemodynamic instabilityb
5 (4.0)
1 (1.0)
0.18
Laboratory data Hemoglobin (g/l)
10.9 ± 3.0
11.5 ± 2.5
0.18
Platelets (103/ll)
21.1 ± 9.3
19.4 ± 5.6
0.36
Blood urea nitrogen (mg/dl)
20.5 ± 12.5
18.7 ± 11.3
0.16
Creatinine (mg/dl)
1.09 ± 1.08
1.00 ± 0.59
0.61
C-reactive protein (mg/dl)
1.32 ± 3.1
1.25 ± 4.2
0.68
Use of enema
7 (5.3 %)
3 (3.0)
0.40
Use of a water-jet scope
30 (19.2)
24 (19.8)
0.90
Failure rate in reaching the cecum
3 (2.3)
2 (2.0)
0.88
Preparation and cecal intubation
Bold values indicate a statistically significant difference with a p value less than 0.05 Values in parentheses show percentages. Values presented with a ± symbol show the mean ± SD. Some patients had more than one comorbidity BMI body mass index, NSAIDs nonsteroidal antiinflammatory drugs, MDCT multidetector contrast-enhanced computed tomography a
BMI data were collected from 110 patients with MDCT and 71 patients without MDCT
b
Hemodynamic instability was defined as initial systolic blood pressure B115 mmHg, initial heart rate C100/min, and the presence of syncope
urgent MDCT and 97 underwent early colonoscopy alone. No significant differences were observed in theage, sex, past history, all comorbidities, initial vital signs, laboratory data, enema, water-jet scope usage, or cecal intubation rate
between the two strategies. The use of NSAIDs and nonaspirin antiplatelets as well as abdominal pain were significantly higher in the MDCT group. Bleeding sources of the lower GI tract are shown in Table 2.
123
J Gastroenterol Table 2 Source of lower gastrointestinal bleeding on colonoscopy with pathology (n = 223) Early colonoscopy following urgent MDCT (n = 126)
Early colonoscopy alone (n = 97)
Diverticular bleeding
77 (61.1)
63 (65.0)
Definitive/presumptive diverticular bleeding
35 (45.5)/22(54.5)
11 (17.5)/52 (82.5)
p
0.56
