JOURNAL OF LAPAROENDOSCOPIC & ADVANCED SURGICAL TECHNIQUES Volume 23, Number 12, 2013 ª Mary Ann Liebert, Inc. DOI: 10.1089/lap.2013.0035
Full Report
Diagnostic Value of Laparoscopy, Abdominal Computed Tomography, and Ultrasonography in Acute Appendicitis Ira Bachar,1,* Zvi Howard Perry, MD,1,2 Larisa Dukhno, MD,3 Solly Mizrahi, MD, FACS,1 and Boris Kirshtein, MD1
Abstract
Background: The most efficient approach to diagnosis of acute appendicitis (AA) continues to be a challenge. We sought to determine diagnostic accuracy, sensitivity, and specificity of computed tomography (CT), ultrasonography, and laparoscopy and compared benefits and advantages in patients with suspected AA. Patients and Methods: A retrospective review of all patients who had laparoscopic surgery between January 2000 and December 2009 was conducted. Preoperative information, surgery results, and outcomes were compared. Results: Of 887 laparoscopic procedures performed for suspected AA, 254 (29%) patients had preoperative imaging: 171 CT scans and 83 ultrasound (US) scans. Overall, 754 patients underwent laparoscopic appendectomy (LA), and 133 underwent diagnostic laparoscopy (DL). DL was negative in 23 patients. The sensitivity of LA was higher than that of CT (98% versus 94%), whereas the specificity of LA was higher than that of CT and US in complicated appendicitis and in women. Complicated AA was significantly less common in patients who underwent laparoscopic surgery compared with patients evaluated by preoperative CT. Comparing the kappa value between the preoperative diagnosis by imaging and DL, a weak agreement was found (j = 0.234 – 0.057). Conclusions: Laparoscopy achieves early and accurate diagnosis of AA and can reduce the incidence of perforated appendicitis. Abdominal CT remains a valuable diagnostic tool. DL is useful in the early stages of the diagnostic work-up and avoids unnecessary exposure to radiation of the abdomen and pelvis in young women.
early laparoscopy have all been described as potential methods for improving diagnosis. The diagnostic accuracy of a US scan has been reported to range from 71% to 97%, whereas that of a CT scan has been reported to range from 83% to 98%.3,4 However, controversy still exists as to the role and benefit of imaging in the work-up for AA and as to clear indications for using these modalities. Diagnostic studies may cause additional delay in definitive management and increase operative risk.4,5 On the other hand, diagnostic laparoscopy (DL) in the acute abdomen offers rapid and accurate diagnosis and subsequent treatment of intraabdominal pathology. Nevertheless, DL and therapeutic laparoscopy are invasive procedures, and there is still controversy about whether this technique should be applied to all patients or reserved for patients in which any doubt still remains for the diagnosis of AA.6
Introduction
A
cute appendicitis (AA) is the most common pathology requiring emergency abdominal surgery. One of the persistent challenges of emergency physicians and general surgeons is to accurately diagnose AA, not only to prevent perforation and peritonitis, but also to prevent unnecessary surgery. Physical examination, laboratory tests, clinical suspicion, additional imaging, and experience can lead to correct diagnosis. Despite advances in surgical diagnosis, the accuracy of clinical diagnosis varies from 71% to 97%,1 with negative appendectomy rates reported up to 20%.2 Computer-aided diagnostic questionnaires, clinical scoring system (Alvarado), active observation, abdominal ultrasound (US), abdominal computed tomography (CT), and
1 Department of Surgery ‘‘A’’ and 3Radiology Institute, Soroka University Medical Center, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. 2 Department of Epidemiology and Health Services Evaluation, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. *This study fulfilled part of the requirements for the MD degree of I.B.
1
2
BACHAR ET AL.
The purpose of this study was to evaluate benefits and clinical outcome and to compare the sensitivity, specificity, and diagnostic accuracy of US, CT, and laparoscopy in AA. Patients and Methods We reviewed the medical records of patients who underwent laparoscopic appendectomy (LA) for AA in our department at Soroka University Medical Center, Beer-Sheva, Israel, between January 2000 and December 2009. After we received the permission of the ethics committee, a list of patients was gathered from the operating room database. Data obtained included demographics, duration of disease before admission, time to surgery, body temperature, laboratory tests, imaging utilization prior to surgery, operative findings, pathology results, and surgery outcomes. Patients were assessed initially by the on-call surgical team. In our service we do not use any scoring systems for diagnosis of AA. Preoperative laboratory tests were used as a part of routine investigation of abdominal pain in the emergency room (ER). All women who suffered from lower abdominal pain underwent a routine gynecological examination to exclude acute gynecological pathology. Patients with obvious clinical diagnosis of AA (local tenderness, guarding, fever, and leukocytosis) and high suspicion for AA (local tenderness, guarding, and no fever or leukocytosis) were considered for urgent laparoscopy. A flowchart of patients with right lower quadrant (RLQ) abdominal pain is presented in Figure 1. LA was performed in patients with AA found during sur-
gery. Laparoscopy was considered diagnostic only when AA was not found and appendectomy was not done. The decision for additional preoperative evaluation was made by the surgeon on call or senior surgeon in cases of insufficient clinical diagnosis at admission or during morning rounds. US was considered in nonobese patients in whom AA was suspected. CT scan was indicated in all other patients and in cases of inconclusive US. CT scan was performed using 1500 mL of oral contrast medium (2% diatrizoate meglumine [Gastrografin; Bristol-Myers Squibb, Wallington, CT]) for bowel opacification 90–120 minutes prior to scanning. The scan was performed with the patient in the supine position, following an intravenous injection of 90 mL of iodinated contrast medium at a rate of 3 mL/second and a scan delay of approximately 50 seconds. Results of CT scans and ultrasonography were interpreted by a staff radiologist. Diagnosis of AA was made when a thickened appendiceal wall or pericecal or periappendicular inflammation with or without intraabdominal fluid was found. Patients with a nonvisualized appendix by CT scan were diagnosed as having no evidence of AA. An appendectomy was performed in all patients with a US or CT scan positive for AA. Patients who had persistent abdominal pain during a 24-hour observation were maintained in the ward on nothing peroral status without using antibiotics. In this group negative imaging for AA was an indication for DL. DL group included patients, in whom appendectomy was not performed. Time to surgery was counted from admission to ER and surgery start. All patients were administered a single dose of
Abdominal pain
Clinical presentation of acute appendicitis
Suspected acute appendicitis
Surgery
Obese patients Female >50 years old
Non-obese male
High suspicion
Intermediate suspicion
Low suspicion
Laparoscopic appendectomy
Open appendectomy
Diagnostic laparoscopy
Investigation
Observation
Non-obese patient
Obese patient
Ultrasonography
Negative
Positive
Suspected acute appendicitis
CT scan
Nonconclusive
Positive
Clinical presentation of acute appendicitis
Surgery
Negative
Surgery
Observation
FIG. 1. Flowchart of patients with abdominal pain. CT, computed tomography.
No pain
Discharge
LAPAROSCOPY AND IMAGING IN ACUTE APPENDICITIS
FIG. 2. Use of additional imaging for diagnosis of acute appendicitis during the study period. CT, computed tomography; US, ultrasound. intravenous metronidazole 500 mg and cefuroxime 750 mg preoperatively. In cases of perforated appendicitis antibiotics were continued for 3 or 5 days. All procedures were performed by or under the guidance of the attending surgeon or chief resident. LA was performed via three ports. An infra- or supra-umbilical 11-mm port was inserted by either the closed (Veress needle) or open (Hasson) technique, and a 45 laparoscope was inserted to examine the abdomen. Two additional ports were inserted under direct vision in the right iliac fossa and either the left iliac fossa or above the pubis. The standard LA technique using bipolar coagulation for mobilization of mesoappendix and endoloop was used for closure of the appendiceal stump. The specimen was extracted inside the 10-mm trocar in the case of a thin appendix or through the one of the ports using a retrieval bag. A diagnosis of AA was based solely on the pathological findings of the appendix. Complicated appendicitis was defined by the finding of a gangrenous or perforated appendix, as well as the presence of an intraabdominal abscess. Patients
3 with a histologically normal appendix or patients with intraoperative findings of other intraabdominal pathologies were classified as ‘‘negative’’ appendectomy. Postoperative complications were determined as infectious when postoperative fever, intraabdominal abscess or phlegmon, wound infection, or urinary tract infection was present after surgery. Data were coded, stored in a Microsoft (Redmond, WA) Office Excel file, and analyzed with SPSS version 17.0 software (SPSS, Inc., Chicago, IL). Data were first analyzed with descriptive statistics (distribution characteristics). Comparison of the groups was done with a Pearson chi-squared test and calculation of kappa for qualitative data and with a Fisher’s exact test for dichotomic variables. Comparison of quantitative data was examined with parametric tests: t test and nonparametric (Mann–Whitney) test. Significance was set at a P value of 60 years old), a high sensitivity was found (98%–100%) in all methods, with no difference among the groups. The specificity of LA was higher than that of CT or US in complicated appendicitis (100% versus 13% and 37%, respectively) and in women (95% versus 72% and 63%,
Table 2. Comparison of Laparoscopy and Imaging US
CT
Overall Sensitivity 74% 94% Specificity 39% 69% PPV 82% 96% NPV 28% 58% Uncomplicated appendicitis Sensitivity 66% 90% Specificity 64% 73% PPV 71% 90% NPV 59% 74% Complicated appendicitis Sensitivity 78% 97% Specificity 37% 13% PPV 23% 25% NPV 88% 92% Male Sensitivity 55% 94% Specificity 100% 77% PPV 100% 95% NPV 17% 71% Female Sensitivity 69% 87% Specificity 63% 72% PPV 66% 86% NPV 66% 74% Age > 60 years Sensitivity 100% 98% Specificity 50% 67% PPV 80% 95% NPV 100% 80% Age
Full Report
Diagnostic Value of Laparoscopy, Abdominal Computed Tomography, and Ultrasonography in Acute Appendicitis Ira Bachar,1,* Zvi Howard Perry, MD,1,2 Larisa Dukhno, MD,3 Solly Mizrahi, MD, FACS,1 and Boris Kirshtein, MD1
Abstract
Background: The most efficient approach to diagnosis of acute appendicitis (AA) continues to be a challenge. We sought to determine diagnostic accuracy, sensitivity, and specificity of computed tomography (CT), ultrasonography, and laparoscopy and compared benefits and advantages in patients with suspected AA. Patients and Methods: A retrospective review of all patients who had laparoscopic surgery between January 2000 and December 2009 was conducted. Preoperative information, surgery results, and outcomes were compared. Results: Of 887 laparoscopic procedures performed for suspected AA, 254 (29%) patients had preoperative imaging: 171 CT scans and 83 ultrasound (US) scans. Overall, 754 patients underwent laparoscopic appendectomy (LA), and 133 underwent diagnostic laparoscopy (DL). DL was negative in 23 patients. The sensitivity of LA was higher than that of CT (98% versus 94%), whereas the specificity of LA was higher than that of CT and US in complicated appendicitis and in women. Complicated AA was significantly less common in patients who underwent laparoscopic surgery compared with patients evaluated by preoperative CT. Comparing the kappa value between the preoperative diagnosis by imaging and DL, a weak agreement was found (j = 0.234 – 0.057). Conclusions: Laparoscopy achieves early and accurate diagnosis of AA and can reduce the incidence of perforated appendicitis. Abdominal CT remains a valuable diagnostic tool. DL is useful in the early stages of the diagnostic work-up and avoids unnecessary exposure to radiation of the abdomen and pelvis in young women.
early laparoscopy have all been described as potential methods for improving diagnosis. The diagnostic accuracy of a US scan has been reported to range from 71% to 97%, whereas that of a CT scan has been reported to range from 83% to 98%.3,4 However, controversy still exists as to the role and benefit of imaging in the work-up for AA and as to clear indications for using these modalities. Diagnostic studies may cause additional delay in definitive management and increase operative risk.4,5 On the other hand, diagnostic laparoscopy (DL) in the acute abdomen offers rapid and accurate diagnosis and subsequent treatment of intraabdominal pathology. Nevertheless, DL and therapeutic laparoscopy are invasive procedures, and there is still controversy about whether this technique should be applied to all patients or reserved for patients in which any doubt still remains for the diagnosis of AA.6
Introduction
A
cute appendicitis (AA) is the most common pathology requiring emergency abdominal surgery. One of the persistent challenges of emergency physicians and general surgeons is to accurately diagnose AA, not only to prevent perforation and peritonitis, but also to prevent unnecessary surgery. Physical examination, laboratory tests, clinical suspicion, additional imaging, and experience can lead to correct diagnosis. Despite advances in surgical diagnosis, the accuracy of clinical diagnosis varies from 71% to 97%,1 with negative appendectomy rates reported up to 20%.2 Computer-aided diagnostic questionnaires, clinical scoring system (Alvarado), active observation, abdominal ultrasound (US), abdominal computed tomography (CT), and
1 Department of Surgery ‘‘A’’ and 3Radiology Institute, Soroka University Medical Center, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. 2 Department of Epidemiology and Health Services Evaluation, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. *This study fulfilled part of the requirements for the MD degree of I.B.
1
2
BACHAR ET AL.
The purpose of this study was to evaluate benefits and clinical outcome and to compare the sensitivity, specificity, and diagnostic accuracy of US, CT, and laparoscopy in AA. Patients and Methods We reviewed the medical records of patients who underwent laparoscopic appendectomy (LA) for AA in our department at Soroka University Medical Center, Beer-Sheva, Israel, between January 2000 and December 2009. After we received the permission of the ethics committee, a list of patients was gathered from the operating room database. Data obtained included demographics, duration of disease before admission, time to surgery, body temperature, laboratory tests, imaging utilization prior to surgery, operative findings, pathology results, and surgery outcomes. Patients were assessed initially by the on-call surgical team. In our service we do not use any scoring systems for diagnosis of AA. Preoperative laboratory tests were used as a part of routine investigation of abdominal pain in the emergency room (ER). All women who suffered from lower abdominal pain underwent a routine gynecological examination to exclude acute gynecological pathology. Patients with obvious clinical diagnosis of AA (local tenderness, guarding, fever, and leukocytosis) and high suspicion for AA (local tenderness, guarding, and no fever or leukocytosis) were considered for urgent laparoscopy. A flowchart of patients with right lower quadrant (RLQ) abdominal pain is presented in Figure 1. LA was performed in patients with AA found during sur-
gery. Laparoscopy was considered diagnostic only when AA was not found and appendectomy was not done. The decision for additional preoperative evaluation was made by the surgeon on call or senior surgeon in cases of insufficient clinical diagnosis at admission or during morning rounds. US was considered in nonobese patients in whom AA was suspected. CT scan was indicated in all other patients and in cases of inconclusive US. CT scan was performed using 1500 mL of oral contrast medium (2% diatrizoate meglumine [Gastrografin; Bristol-Myers Squibb, Wallington, CT]) for bowel opacification 90–120 minutes prior to scanning. The scan was performed with the patient in the supine position, following an intravenous injection of 90 mL of iodinated contrast medium at a rate of 3 mL/second and a scan delay of approximately 50 seconds. Results of CT scans and ultrasonography were interpreted by a staff radiologist. Diagnosis of AA was made when a thickened appendiceal wall or pericecal or periappendicular inflammation with or without intraabdominal fluid was found. Patients with a nonvisualized appendix by CT scan were diagnosed as having no evidence of AA. An appendectomy was performed in all patients with a US or CT scan positive for AA. Patients who had persistent abdominal pain during a 24-hour observation were maintained in the ward on nothing peroral status without using antibiotics. In this group negative imaging for AA was an indication for DL. DL group included patients, in whom appendectomy was not performed. Time to surgery was counted from admission to ER and surgery start. All patients were administered a single dose of
Abdominal pain
Clinical presentation of acute appendicitis
Suspected acute appendicitis
Surgery
Obese patients Female >50 years old
Non-obese male
High suspicion
Intermediate suspicion
Low suspicion
Laparoscopic appendectomy
Open appendectomy
Diagnostic laparoscopy
Investigation
Observation
Non-obese patient
Obese patient
Ultrasonography
Negative
Positive
Suspected acute appendicitis
CT scan
Nonconclusive
Positive
Clinical presentation of acute appendicitis
Surgery
Negative
Surgery
Observation
FIG. 1. Flowchart of patients with abdominal pain. CT, computed tomography.
No pain
Discharge
LAPAROSCOPY AND IMAGING IN ACUTE APPENDICITIS
FIG. 2. Use of additional imaging for diagnosis of acute appendicitis during the study period. CT, computed tomography; US, ultrasound. intravenous metronidazole 500 mg and cefuroxime 750 mg preoperatively. In cases of perforated appendicitis antibiotics were continued for 3 or 5 days. All procedures were performed by or under the guidance of the attending surgeon or chief resident. LA was performed via three ports. An infra- or supra-umbilical 11-mm port was inserted by either the closed (Veress needle) or open (Hasson) technique, and a 45 laparoscope was inserted to examine the abdomen. Two additional ports were inserted under direct vision in the right iliac fossa and either the left iliac fossa or above the pubis. The standard LA technique using bipolar coagulation for mobilization of mesoappendix and endoloop was used for closure of the appendiceal stump. The specimen was extracted inside the 10-mm trocar in the case of a thin appendix or through the one of the ports using a retrieval bag. A diagnosis of AA was based solely on the pathological findings of the appendix. Complicated appendicitis was defined by the finding of a gangrenous or perforated appendix, as well as the presence of an intraabdominal abscess. Patients
3 with a histologically normal appendix or patients with intraoperative findings of other intraabdominal pathologies were classified as ‘‘negative’’ appendectomy. Postoperative complications were determined as infectious when postoperative fever, intraabdominal abscess or phlegmon, wound infection, or urinary tract infection was present after surgery. Data were coded, stored in a Microsoft (Redmond, WA) Office Excel file, and analyzed with SPSS version 17.0 software (SPSS, Inc., Chicago, IL). Data were first analyzed with descriptive statistics (distribution characteristics). Comparison of the groups was done with a Pearson chi-squared test and calculation of kappa for qualitative data and with a Fisher’s exact test for dichotomic variables. Comparison of quantitative data was examined with parametric tests: t test and nonparametric (Mann–Whitney) test. Significance was set at a P value of 60 years old), a high sensitivity was found (98%–100%) in all methods, with no difference among the groups. The specificity of LA was higher than that of CT or US in complicated appendicitis (100% versus 13% and 37%, respectively) and in women (95% versus 72% and 63%,
Table 2. Comparison of Laparoscopy and Imaging US
CT
Overall Sensitivity 74% 94% Specificity 39% 69% PPV 82% 96% NPV 28% 58% Uncomplicated appendicitis Sensitivity 66% 90% Specificity 64% 73% PPV 71% 90% NPV 59% 74% Complicated appendicitis Sensitivity 78% 97% Specificity 37% 13% PPV 23% 25% NPV 88% 92% Male Sensitivity 55% 94% Specificity 100% 77% PPV 100% 95% NPV 17% 71% Female Sensitivity 69% 87% Specificity 63% 72% PPV 66% 86% NPV 66% 74% Age > 60 years Sensitivity 100% 98% Specificity 50% 67% PPV 80% 95% NPV 100% 80% Age
