As the more commonly emplsoyed approach, the general Clavien-Dindo classification standard for postoperative complications was initially proposed by Professor Pierre-Alain Clavien of the University Hospital of Zurich in Switzerland in 1992 1, which was based on a survey of 6336 patients, predominantly based on "life-threatening" and "permanent disability" grades, divided into 4 grades according to postoperative adverse events. In 2004, Professors Dindo and Clavien of the University Hospital of Zurich, Switzerland revised the grading standards. This revision was essentially premised upon a "complication-based treatment" classification and was divided into 5 grades according to postoperative adverse events 2. The advantages to this revision included added simplicity and ease of use, allowing for a wider use in the surgical clinical field 3. However, this classification lacks consistency in terms of its definition of postoperative adverse events of different surgical procedures, which may lead to bias in the classification of complications in specific work. Therefore, in 2015, the Japanese Clinical Oncology Collaboration Group created the "JCOG Postoperative Complication Standard" based on the Clavien-Dindo grading system and the National Cancer Institute CTCAE adverse event grading standard. 4 This standard was comprised of 72 surgical complications (emphasis includes 17 gastrointestinal-related complications, 13 infection-related complications, and 6 thoracic surgery-related complications), listing the common adverse events associated with surgical procedures and optimizes them. The classification of the surgical complications is clearly defined, allowing for a more unified standard, suitable for the evaluation of early postoperative complications. For example, the placement of a gastric tube and a small intestinal decompression tube after intestinal obstruction after surgery are grade Ⅱ and Ⅲ complications, respectively, and the postoperative digestive tract leakage puncture or replacement of the drainage tube listed as grade Ⅲa complications. The current study adopted the JCOG postoperative complication standard, that is, the modified Clavien-Dindo classification as the standard for evaluating postoperative complications.
Our study highlighted 114 cases of early complications after radical gastrectomy (Clavien-Dindo ≥ I), 20 cases of which were early postoperative severe complications Clavien-Dindo grade ≥ IIIa. No postoperative deaths took place. Pneumonia, gastrointestinal symptoms (abdominal distension and reflux) after operation, duodenal stump leakage, abdominal hemorrhage, gastroparesis, chylous leakage, and ascites were still common early complications after radical gastrectomy. The most common complication associated with radical gastric cancer was pneumonia (42 cases), taking place at a rate of 8% (42/525), which is in line with existing literature results 9. Reasons for analysis may include: 1. The average age of patients is (62.5 ± 10.7) years old, the proportion of patients ≥ 70 years old is 28.8%, the lung elasticity and chest wall compliance of elderly patients are naturally reduced, the amount of residual alveolar gas is increased, elderly patients tend to be more prone to respiratory muscle fatigue and upper respiratory tract obstruction 10. 2. The proportion of males in this data set was 73.7% (387/525), which is essentially consistent with the data the geographical Cancer Registry 11; A greater proportion of male patients smoke (117/387), which heightens their chances of falling victim to postoperative pneumonia 12. 3. Approximately 76% (404/525) of our patients underwent open operations. The post-operative pain associated with this approach often prevents patients from clearing sputum effectively and can affect the process of deep breathing, ultimately affecting diaphragm activity, leading to a greater degree of difficulty in recruiting the lower lobes of the lung, all of which markedly elevates the chances of infection 13. 4. The proportion of total gastrectomy in this study was high, accounting for approximately 62.9% (330/525). Previous studies have highlighted pneumonia as a notable post-operative risk associated with total gastrectomy 14. 5. The author's institution often ensures the routine placement of gastric tube and jejunal nutrition tube after surgery, which may contribute to the occurrence of lung infection.
The most serious postoperative complications included duodenal stump leakage (10 cases), accounting for 8.8% (10/114) of the total postoperative complications and 50% (10/20) of the severe complications, consistent with existing literature 15. Reasons: 1. Related to the age of preoperative patients, Filip B and others reviewed 189 cases of radical gastric cancer surgery through a single center and identified age as an independent risk factor for postoperative surgical complications 16; 2. The preoperative comorbidity rate was 23.4% (123/525), while the preoperative multiple comorbidity rate was 5.5% (29/525). Paik et al. concluded that preoperative multiple comorbidity was the main reason of postoperative duodenal stump fistula. 17; 3. In the past, the stump was only reinforced, but not embedded. Following a review and technical improvement, the stump was embedded, which allowed for a marked reduction in leakage from the duodenal stump. 18, 19. Interestingly, all duodenal stump leakage took place after total gastrectomy in our institution, no duodenal stump leakage occurred after distal gastrectomy, which may relate to some patients with distal gastrectomy using of a double cannula for preventive irrigation. All duodenal stump leakage was treated by double cannula irrigation or puncture and drainage, with no additional surgery required.
In addition, no jejunum-jejunum anastomosis and stump leakage occurred after total gastrectomy, indicating that Roux-and-y jejunal anastomosis is not associated with certain complications such anastomotic leakage. It is worth noting that intra-abdominal hemorrhage should attract the attention of the surgeon, as 2 of the 5 cases of intra-abdominal hemorrhage resulted in the requirement of additional surgery, which may be associated with increased blood clots in the abdominal cavity after hemorrhage. This can lead to repeated exudation and consumption of platelets. Two cases of anastomotic hemorrhage were flushed through the stomach tube and injected locally with hemostatic drugs, suggesting that the prognosis of anastomotic hemorrhage was superior to intra-abdominal hemorrhage.
Through multi-factor analysis, it was identified that blood loss was a twofold independent risk factor for postoperative complications and severe postoperative complications, which was in line with existing literature reports 20, 21. Reasons: 1. Excessive bleeding during surgery not only affects the stability of intraoperative hemodynamics, but also may affect the mood of the surgeon, which is not conducive for the high-quality completion of the operative procedure. 2. Postoperative anemia patients often display a poor general condition and a lesser threshold for stress, which is not conducive for the healing of an anastomosis or stump 22. 3. Anemia can negatively influence the immune system, and lead to insufficient tissue oxygenation, low protein levels, and increase the risk of infection 23.
The current study identified age as an independent risk factor for postoperative complications. Firstly, elderly patients often have reduced lung function prior to surgery, poor sputum excretion after surgery, and it’s worth noting that upper abdominal surgical wounds are likely to affect the diaphragm, resulting in an increased incidence of lung infections. Through retrospective analysis of 750 cases of gastric cancer surgery, Miki Y et al reported age as an independent risk factor for postoperative lung infection 10. Second, elderly patients with gastric cancer were often accompanied by hypoproteinemia, prone to anastomosis and stump leakage 16. Finally, elderly patients exhibited a high ASA score prior to surgery, which was closely linked with the occurrence of complications. Nelen SD et al. found through a gastric cancer cohort study that the ASA score of elderly patients was significantly higher than that of the younger group. In addition, patients over 70 years old were risk factors for postoperative complications 24.
Comorbidity prior to surgery represents an independent risk factor for postoperative complications. During the present study, the combination of complications and hypertension was up to 16.8% (88/525). Filip B et al. reviewed 189 cases of radical gastric cancer surgery through a single center and found that hypertension was a dual independent risk factor for postoperative complications and surgical complications 16, Choudhuri AH et al. analyzed 137 cases of gastrointestinal leak after gastrointestinal surgery and found that hypertension was also an independent risk factor for gastrointestinal leak 22. In addition, COPD as well as coronary heart disease contribute to an increased probability of postoperative complications. Coimbra FJF and others retrospective analyzed of 1223 patients with gastric cancer surgery, highlighting hypertension, COPD, and diabetes as the most common comorbidities before surgery, while COPD, coronary heart disease were independent risk factors for postoperative complications 25. Finally, diabetic patients are often prone to triggering a greater stress response as well as an increase in insulin resistance, making it difficult to control blood glucose, which can easily lead to complications such as incision infection, poor healing, and anastomotic leakage. Wang JB and others retrospectively analyzed 1657 cases of laparoscopic-assisted total gastrectomy, this passage found that diabetes was closely related to the occurrence of postoperative anastomotic leakage, abdominal bleeding, and lung infection 26.
Open surgery is an independent risk factor for postoperative complications, similar to the results of other literature 13, 27. Reasons behind this include: 1. Following laparoscopic, surgery patients recovery is faster, with a significantly less deal of pain experienced, which is conducive for deep breathing, effective sputum excretion, and a greater ability to use lung capacity in a postoperative state, reducing the probability of lung infection. After laparoscopic surgery, patients often quickly recover intestinal function. They can take food and get out of bed early, increase nutrition and immunity, reducing the chances of ascites occurring due to hypoproteinemia, and diminishes the probability of venous thrombosis and atelectasis taking place, both of which have been strongly associated with long-term bed rest.
In addition, total gastrectomy was an independent risk factor for severe postoperative complications. Compared with subtotal gastrectomy, the range of total gastrectomy is larger, and the number of anastomoses is increased 24. 1. Our institution often performs routine gastrectomy for D2 lymph node dissection for advanced gastric cancer, so the incidence of postoperative chylus leak increases. 2. As per the Japanese Gastric Cancer Protocol, as part of the D2 dissection, the splenic hilar lymph nodes were routinely cleaned in my unit. When performing splenic hilar lymph node dissection, the blood vessels are easily damaged which can also lead to splenic bleeding; 3. Due to the anatomic position of the esophagus, it is difficult to reconstruct the digestive tract, particularly when performing anastomosis of the esophagus and jejunum. In certain instances the anastomosis cannot be strengthened, which can lead to anastomotic bleeding and anastomotic leakage; 4. When the splenic hilar and mediastinal lymph nodes are removed, the incidence of pleural effusion and pneumothorax increased (in this group, 1 case of pneumothorax and 2 cases of pleural effusion be performed pleural drainage after total gastrectomy).
Interestingly, the current study detected that pathological nerve involvement is related to the occurrence of serious postoperative complications. The specific reason is not clear and requires further investigation with a larger sample size.
The 5-year survival period of the severe complication group was only 35%, which was different from that of the non-severe complication group (61.8%), but the COX model suggested that severe complications were not independent risk factors affecting the prognosis, which was inconsistent with some literature results. 28, 29. We believe that the reasons may be: 1. Our inclusion of variables that may affect prognosis (age, gender, histological type, TNM stage, preoperative comorbidity) into the COX model. The final preoperative comorbidity and TNM stage are independent risk factors that affect the prognosis, so they offset the risk of severe complications.2. No deaths took place in the severe complication group, and the end event of OS was death, thus severe complications may not be the cause of an independent prognostic risk factors.3. COX multivariate analysis showed that severe postoperative complications (HR = 1.595, P = 0.107), although P > 0.05, however the distance from clinical significance is small, which may be related to the small sample size of the group of severe complications (n = 20).4. Gastrointestinal complications (such as nausea, gastrointestinal reflux, anastomotic stenosis) in the non-severe complications group may lead to poor postoperative nutritional status and potentially affect long-term prognosis.
The advantages of our study include: The document database was registered by a special person since October 2010, and someone regularly checked to ensure the authenticity and correctness of the data, 2. Strictly grade the complications in accordance with the improved Clavien-Dindo complication standard. All staff in the department participate in the follow-up of patients and centrally register and update the data, further enhancing the quality of the database.
There were certain limitations faced during the investigation: 1. Due to the high population mobility in China and the fact that some rural areas have are not conducive for timely follow up, (by telephone, correspondence, household registration, internet, etc.). Additionally, the time and location of tumor recurrence and metastasis in some patients are difficult to record, so only the overall survival OS was recorded. 2. The aim of the current study was to investigate the occurrence of early postoperative complications, and to minimize the confounding factors via inclusion and exclusion criteria through the use of a retrospective descriptive study, which by nature has its own limitations. The research evidence is low, and it needs to be further confirmed by a multi-center, large-sample prospective cohort study.3. The study showed that there was no difference in survival between the early postoperative severe complications group and the non-severe complications group, which may be related to the small sample size of the severe complications group (n = 20), which needs to be confirmed in a larger sample size.4. This study utilized the definition of ‘early postoperative’ from surgery until the initial hospital discharge time, with some patients having complications after discharge, thus were not included in the study.