Abstract
Background/Aim: The significance of spirometry as preoperative risk assessment for gastrointestinal surgery has been controversial. At the beginning of the COVID-19 pandemic, preoperative spirometry was temporarily suspended in our institute. This study was aimed to investigate the necessity of spirometry for gastrointestinal cancer surgery. Patients and Methods: We compared short-term postoperative outcomes between 318 patients who underwent surgery for colorectal or gastric cancer with (Spirometry group; n=272) or without spirometry (Non-spirometry group; n=46). Results: Respiratory functional disorders were detected in 77 (28.3%) patients in the Spirometry group. No significant differences were noted in complications, including pneumonia, or the length of hospital stay between the two groups. An advanced age, male sex, comorbidities with respiratory diseases, and a smoking history significantly correlated with abnormal results in spirometry. Conclusion: Preoperative spirometry may be substituted with other clinical factors in patients with gastrointestinal cancer.
Spirometry has been widely used as an objective screening examination for pulmonary function. Pulmonary diseases, such as chronic obstructive respiratory disorder (COPD), interstitial lung disease, and asthma, are closely related with abnormal pulmonary functions. Therefore, in patients with thoracic surgery, preoperative spirometry is generally performed to predict the risk of postoperative pulmonary complications (PPCs) (1). However, the efficacy and necessity of spirometry in patients with non-thoracic surgery are still controversial (2-5). In our institute, spirometry is generally conducted to assess preoperative respiratory risks for all patients undergoing gastrointestinal surgery, as in the majority of hospitals in Japan. However, the American College of Physicians guidelines recommend preoperative spirometry only for high-risk patients with pulmonary diseases, not for all patients (6). As minimally invasive surgery has been widely performed in these days, the value of spirometry in gastrointestinal surgery should be reconsidered.
The World Health Organization declared a pandemic of Corona Virus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on March 11th, 2020. Information on the infectivity and mode of transmission of this virus was extremely limited, particularly in the early stage; therefore, the pandemic had a significant impact on several medical examinations and surgeries. In our institute, spirometry was temporarily suspended due to the risk of unknown-virus exposure.
Therefore, we herein investigated the effects of changes in preoperative examinations on short-term postoperative outcomes and the necessity of spirometry in patients who underwent surgery for colorectal cancer (CRC) or gastric cancer (GC).
Patients and Methods
Study design. This is a retrospective study conducted on patients with colorectal or gastric cancer who underwent curative surgery at Kyoto Prefectural University of Medicine between January 2019 and August 2020. Preoperative spirometry was suspended in consideration of the risk of virus exposure between April 13th and July 20th, 2020. Regarding preoperative examinations for respiratory functions, chest computed tomography (CT) was routinely performed and an arterial blood gas test (ABGT) was conducted as an alternative to spirometry during that period. At our institute, the polymerase chain reaction (PCR) examination to detect the DNA of the virus started to be routinely performed before hospital admission from May 25th, 2020. However, since a routine PCR examination was not performed prior to preoperative examinations at the outpatient clinic, there was a risk of virus exposure during these experiments, particularly spirometry. We compared short-term postoperative outcomes between patients with (spirometry group) or without spirometry (non-spirometry group). Comorbidities included respiratory diseases that previously or currently require medical treatment. In spirometry, restraint ventilatory defects are defined as percent venture capital (%VC) <80%, obstructive ventilatory defects as forced expiratory volume in one second/forced vital capacity ratio (FEV1.0%) <70% or less, and mixed ventilatory defects satisfied both conditions. COPD was also defined as FEV1.0% <70% or less and classified according to percent predicted forced expiratory volume in one second (%FEV1.0). In our institute, a preoperative respiratory rehabilitation was not routinely performed for patients with abnormal data by spirometry, and the patients whose forced expiratory volume in one second (FEV1.0) was one litter or less were temporarily managed in an intensive care unit after surgery with general anesthesia, in principle. The right colon included the cecum/ascending/transverse colon, while the left colon included the descending/sigmoid/rectosigmoid colon. Complications of Grade II or higher in the Clavien-Dindo classification within 30 days after surgery were defined as postoperative complications.
Participants. A total of 330 patients were assessed. The following patients were excluded: six with multiple cancers, two who underwent mediastinoscopic operation, two who underwent emergency surgery, and two with insufficient data. Eventually, 272 and 46 patients were classified into the spirometry and non-spirometry groups, respectively. The present study was approved by the Ethics Committee of the Kyoto Prefectural University of Medicine (approval number: ERB-C-1178-1), and all patients provided written informed consent for the use of their data for clinical studies.
Statistical analysis. Differences between proportions were assessed using the chi-squared test, and the Student’s t-test (for comparisons between two groups) was used to examine continuous variables. A p-value <0.05 was considered to indicate a significant difference. Statistical analyses were conducted with the statistical software JMP version 12.2.0 (SAS Institute Inc., Cary, NC, USA).
Results
The characteristics of all 318 patients are shown in Table I. The numbers of patient with colorectal and gastric cancer were 208 and 110, respectively. No significant differences were observed in tumor location, age, sex, body mass index, or smoking history between the two groups. Also, no significant differences were noted in previous histories of respiratory comorbidities, including bronchial asthma, interstitial pneumonia, tuberculosis, pulmonary embolism, and other respiratory diseases between the two groups. In the spirometry group, respiratory functional disorders were detected using preoperative spirometry in 77 patients (28.3%): 37 (13.6%), 33 (12.1%), and 7 (2.6%) had obstructive, restrictive, and mixed ventilatory impairments, respectively. Symptomatic COPD was observed in 2 (0.7%) cases and asymptomatic in 42 cases (15.4%).
The clinical characteristics of all patients.
Table II shows a summary of surgical outcomes. No significant differences were observed in surgical procedure, surgical approach, surgical time, or volume of blood loss between the two groups. In both groups, 75% or more of patients underwent minimally invasive approaches, including laparoscopic and robot-assisted surgeries.
The summary of operative outcomes in the two groups.
Short-term postoperative outcomes are shown in Table III. No significant differences were observed in complications, including pneumonia, surgical site infection, anastomotic leakage, bowel obstruction/ileus, and reoperation, between the two groups. No patient in the non-spirometry group and 5 (1.8%) in the spirometry group had postoperative pneumonia. Although only one (1/208, 0.5%) had postoperative pneumonia in patients with CRC, four (4/110, 3.6%) had postoperative pneumonia in patients with GC. The length of hospital stay did not significantly differ between the two groups (non-spirometry group; 9 days, spirometry group; 11 days, p=0.281), and no mortalities occurred in either group.
The short-term postoperative outcomes in the two groups.
Table IV shows the clinical factors associated with abnormal respiratory function detected by preoperative spirometry. A patient age of 65 years or older, male sex, a smoking history, and the presence of comorbidities with respiratory diseases, significantly correlated with abnormal results in spirometry by both univariate and multivariate analyses.
The factors associated with results of spirometry.
Discussion
Preoperative spirometry for the assessment of pulmonary functions is important for preventing postoperative complications, especially pulmonary complications. Among patients undergoing non-cardiothoracic surgery, the American College of Physicians guidelines recommend preoperative spirometry only for high-risk patients with pulmonary diseases such as asthma and COPD, but not for all patients (6). However, the efficacy and necessity of spirometry in patients with non-thoracic surgery, including gastrointestinal surgery, remains controversial (2-5, 7). Tajima et al. reviewed 1,236 patients who underwent CRC surgery and recommended to perform spirometry to predict postoperative pneumonia (4). However, Huh et al. reported that spirometry was not useful to predict PPCs in GC patients aged 60 years or older (2). In our institute, as well as many institutes in Japan, spirometry has been routinely performed for all patients before surgery under general anesthesia to design the intra- or postoperative patient management and consequently prevent postoperative respiratory complications. In the present study, short-term postoperative outcomes were compared between patients with or without a preoperative risk assessment by spirometry to evaluate the necessity of spirometry in patients with colorectal or gastric cancer.
Spirometry is associated with a risk of virus exposure and, thus, guidance on safely performing spirometry during the COVID-19 pandemic has been offered to physicians in some countries (8). In our institute, after the spread of the COVID-19 pandemic, as preoperative spirometry was suspended due to the lack of accurate information and the fear of exposure to an unknown virus, clinical findings such as chest CT, ABGT, smoking history, and respiratory related-comorbidities were conducted as alternatives to spirometry. Concerning about the impact on short-term postoperative outcomes by changes in preoperative risk assessments, we conducted this retrospective study. The present study revealed no significant differences in postoperative complications, or the length of hospital stays between the two groups, and there were no mortalities. In this study, the incidence of postoperative pneumonia was 3.6% (4/110) and 0.5% (1/208) in patients with GC and CRC, respectively. Of the GC patients with postoperative pneumonia, two patients developed other complication simultaneously and the other two patients (1.8%) developed postoperative pneumonia alone. Considering previous studies with a large number of patients reporting that the incidence of postoperative pneumonia of GC was 1.2% and that of CRC was 0.2%, our results are reliable (9, 10). Furthermore, considering the difference between patients with GC and CRC, Canet et al. reported the upper abdominal surgery was one of the independent risk factors for PPCs (11). Furthermore, Simonneau et al. indicated that upper abdominal surgery induced a diaphragmatic dysfunction, which might cause postoperative pneumonia (12).
Our study showed that abnormal respiratory function was observed in 28.3% of patients in the spirometry group. Regarding the alternatives to spirometry for preoperative risk assessments, the present results suggest that an advanced age, male sex, respiratory related- comorbidities, and smoking history are risk factors associated with respiratory functional disorders, which was supported by other studies (3, 6, 13, 14). Jeong et al. evaluated the predictive value of spirometry for all kinds of morbidity in GC patients and concluded that abnormal pulmonary function detected by spirometry was significantly related to surgical complications, such as wound infections and anastomotic leakage. However, PPCs were not predicted by spirometry, but older age and history of pulmonary disease were significantly related to the incidence of PPCs (3). Taken together, it may be acceptable that alternatives to spirometry are sufficient to predict PPCs in patients with gastrointestinal cancer, especially CRC.
There are some limitations to the present study. Few patients had symptomatic COPD as a comorbidity in this cohort. Lemmens et al. reported that the presence of COPD correlated with postoperative pneumonia in patients with CRC (15). However, since some patients had asymptomatic COPD diagnosed by spirometry, those in the non-spirometry group may have been overlooked. Furthermore, previous studies reported that laparoscopic surgery was associated with a reduced risk of respiratory complications after colorectal surgery among patients with COPD (16) and elderly patients (17). Laparoscopic or robot-assisted surgeries were performed on more than 75% of patients, which may explain why postoperative pneumonia rarely occurred in the present study. Furthermore, the number of patients included in the present study was relatively small. However, as the indication of preoperative spirometry was determined by the COVID-19 pandemic, no selection bias existed, which was a strong point of this study. A large-scale clinical trial needs to be conducted in order to clarify the validity of eliminating spirometry before colorectal surgery.
In conclusion, the suspension of spirometry as a preoperative risk assessment did not significantly affect short-term results in patients with colorectal and gastric cancer. It may be acceptable to substitute risk assessments of postoperative pneumonia with previous histories of respiratory disease and smoking in patients with gastrointestinal, especially colorectal, cancer.
Footnotes
Authors’ Contributions
M. Mitsuda and H. Shimizu conceived and designed the study and edited the manuscript. T. Arita, T Ohashi, J Kiuchi, Y. Yamamoto, H. Konishi, R. Morimura, A. Shiozaki, H. Ikoma, H. Fujiwara, and K. Okamoto helped to obtain patients’ data. Y. Kuriu, T. Kubota and E. Otsuji revised the manuscript. M. Mitsuda and H. Shimizu conceived and designed the study and edited the manuscript. All Authors read and approved the final version of this manuscript.
Conflicts of Interest
The Authors have no conflicts of interest to declare in relation to this study.
- Received January 5, 2022.
- Revision received January 19, 2022.
- Accepted January 20, 2022.
- Copyright © 2022 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.
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