Discussion
For patients with gastrointestinal malignancies and severe coronary stenosis, the choice between staged or simultaneous surgeries is still controversial. Staged radical resection of the tumor following CABG has been the traditional approach in the past 9, 10. However, it has been reported that a second non-cardiac surgery within 30 days has a higher risk of death and cardiovascular complications. In general, it is recommended that the subsequent operation be performed six to 12 weeks after grafting 11. In addition, the general nutritional status of gastrointestinal tumor patients was lower, and the recovery time after CABG was longer. Takahashi and colleagues reported that the second operation was delayed in three of nine patients who received staged surgery due to slow recovery following CABG, with an average interval of seven weeks 12. Importantly, the tumor may progress while patients are awaiting radical surgery. Additionally, heparinization during CABG and postoperative antiplatelet therapy may lead to gastrointestinal malignancy bleeding, which could be life-threatening. Therefore, to avoid the above shortcomings of staged surgeries, concurrent surgeries may be a better option. In addition, the concurrent surgeries can also reduce the immunosuppression caused by twice the anesthesia, reduce the long-term recurrence rate of the tumor caused by blood transfusions 13, reduce the pain experienced by patients, and it has health and economic benefits.
More than 20 patients with gastric cancer and 10 patients with bowel cancer have received simultaneous CABG and radical gastrointestinal tumor resection 14-16. There were no perioperative deaths, and no occurrences of postoperative myocardial infarction or heart failure. A total of five patients at our center were discharged smoothly without adverse events. There were no perioperative deaths, and no serious cardiovascular events or anastomosis fistulas following the concurrent surgeries. Two of the gastric cancer patients died at 28 and 37 months due to tumor metastasis, which may be related to the late postoperative pathological stage. Our case series suggests that patients with gastrointestinal tumors and severe coronary heart disease who underwent concurrent OPCAB and radical resection of their gastrointestinal tumors may have better short-term results, and the long-term prognosis may be related to tumor staging.
Although concurrent surgeries have many advantages over staged surgeries, combined surgery often takes a long time and is more traumatic to the patient. Therefore, it is necessary to strictly control the surgical indications for this type of surgery. Shapira et al.reported that CABG in patients with left ventricular ejection fraction (LVEF) < 30% can be performed with low mortality, but with higher morbidity and longer length of hospital stay compared to patients with LVEF > 30% 17. Zhang and colleagues proposed that concurrent surgery is not recommended for patients with LVEF < 45% 18, and Davydov and colleagues have stated that LVEF < 20% is a contraindication for concurrent surgery 16. However, Takahashi et al. reported that concurrent CABG and radical gastrointestinal tumor resections were safe and feasible in patients with low LVEF14. At present, the ejection fraction (EF) value of patients undergoing concurrent surgery is generally > 30%, and the average LVEF in our study group was 56.8% (45-65%). In general, low LVEF does not affect the simultaneous operations, but if it is too low (especially < 20%), it may be contraindicated.
The management of patients with severe coronary stenosis who present with acute heart failure may be a more difficult challenge for cardiac surgeons. Most scholars believe that left heart failure that requires large doses of cardiotonic drugs or mechanical circulatory support is a contraindication to simultaneous surgery, and these patients should be operated on in stages 14. Among our patients, OPCAB was urgently performed on case 2 because of acute left heart failure. After OPCAB, the patient had stable hemodynamics and no obvious bleeding tendencies, so he immediately underwent radical resection of gastric cancer. This is the first case of heart failure that underwent simultaneous CABG and radical tumor resection, which has provided a potential solution for the treatment of such patients.
In addition to the condition of the heart, the surgery required for the abdominal tumor is also an important factor in considering whether to perform the operations at the same time. Tsuji et al . reported that CABG and total gastrectomy at the same time have a higher risk of mediastinal infection, and proposed that CABG and total gastrectomy should be performed in stages, with the total gastrectomy being performed three to six weeks after CABG 10. Takahashi suggested that patients with severe coronary heart disease undergoing resection of high-risk tumors, such as esophageal cancer and pancreatic cancer, should also undergo staged surgeries 14. In addition, Komokata and colleagues published a report on an 83-year-old patient with chronic obstructive pulmonary disease (COPD) who underwent simultaneous aortic valve replacement and radical gastric cancer surgery, and died of respiratory failure following the operation, suggesting that advanced age and COPD are high risk factors for poor outcomes in simultaneous surgeries 15.
CABG and percutaneous coronary intervention (PCI) are both strategies of coronary revascularization, but making a choice between the two is still controversial. The SYNTAX trail showed that CABG had a mortality benefit over PCI in patients with multi-vessel disease, particularly in those with diabetes and higher coronary complexity 19. For patients with coronary heart disease undergoing non-cardiac surgery, it is recommended to implant bare stents instead of drug-eluting stents, because this can shorten the time interval between subsequent operations20. The ideal interval to perform non-cardiac surgery after implantation of bare stents is three months, when the principle negative events (death, myocardial infarction, stent thrombosis and revascularization) are lowest 21. Therefore, CABG may be a more reasonable choice for revascularization compared to PCI for patients with multi-vessel disease undergoing surgery for gastrointestinal cancer. After multidisciplinary discussions between cardiologists and cardiac surgeons, we finally decided to adopt CABG as the strategy of coronary revascularization.
Randomized controlled clinical trials have shown that OPCAB and on-pump CABG have a similar early and late graft patency rate, revascularization rate and long-term prognosis 22. For surgeons with excellent surgical skills, the incidence of morbidity (stroke, atrial fibrillation and infection) after OPCAB is lower 23. Compared with on-pump CABG, OPCAB can reduce the risk of gastrointestinal bleeding caused by heparinization, reduce the systemic inflammatory response, and will not enhance tumor progression due to cardiopulmonary bypass 24. Similar to the suggestion offered by Komokata et al. , OPCAB may be more reasonable for cancer patients. The use of arterial grafts is beneficial to the long-term prognosis of CABG, especially the internal mammary artery. The internal mammary artery was anastomosed to the anterior descending branch. The radial artery is the second choice, and its long-term patency is better than vein usage 25, but inferior to the internal mammary artery 26. However, it takes longer to obtain arterial grafts than venous grafts. We recommend that it is necessary to combine the prognosis of patient and the state of the surgery to decide which type of graft to use. If the long-term prognosis is poor, a venous graft may be a more appropriate choice. If the tumor stage is early and the life expectancy is long, total arterial grafts should be used as far as possible. The preoperative tumor staging of case 2 indicated that the gastric cancer stage was late and the patient with acute left heart failure underwent emergency CABG, so the great saphenous vein was selected as the grafting vessel. The patient of case 5 was younger, had a relatively early preoperative tumor stage, and has colorectal cancer. Therefore, two arterial grafts from the left internal mammary artery and radial artery were used.
Except in case 2, the remaining four patients in this study were all associated with unstable angina. Before surgery, aspirin and clopidogrel were stopped for seven days according to relevant guidelines, and low molecular weight heparin was injected subcutaneously for bridging27. Gastric cancer patients were given a nutrient solution and antiplatelet drugs through the nasal feeding tube on the first day after surgery. Patients with colorectal cancer were given intravenous nutrition after surgery, and low molecular weight heparin was given subcutaneously before eating while oral antiplatelet drugs were given after eating. By following this principle of discontinuation and administration, none of the four patients experienced perioperative severe angina pectoris or severe gastrointestinal bleeding. Case 4 showed signs of gastrointestinal bleeding after antiplatelet drugs were given following surgery. When the antiplatelet drugs were stopped and conservative treatment was provided, the patient improved after four days. No cardiovascular symptoms such as chest tightness or shortness of breath were seen during the withdrawal. According to our experience, an indwelling small intestinal nutrition tube placed during the operation has many advantages; not only can nutrition be supplied through the tube as soon as possible to promote the early recovery of digestive tract function, it can also be used to infuse antiplatelet drugs early to reduce the risk of acute thrombosis of the coronary anastomosis.
We found that the concurrent radical resection of the gastrointestinal tumor was performed under stable hemodynamics, and the radical resection of the operation was not affected 28. The follow-up data also suggest that the overall survival and relapse-free survival after the concurrent surgeries are equivalent to those of radical gastrointestinal surgery alone 29. A study of concurrent surgery for gastric cancer and CABG suggested that the long-term prognosis depends on the staging status of the gastric cancer at the time of diagnosis 10.
Anastomotic leakage is a common and serious complication. There has been no significant difference reported in the proportion of anastomotic leakage between staged and simultaneous surgeries 15, 30. However, there are some special considerations for concurrent surgeries, such as the location of the advanced tumor, that influence whether or not to perform the extended radical operation. If there is incomplete colonic obstruction before the operation, the surgeons need to consider the pros and cons to decide whether to anastomose. Tsujiet al . recommended that aggressive concurrent surgical interventions might bring a benefit to the patients whose survival periods are expected to be more than six months 10. In our group of patients, incomplete colonic obstruction was found preoperatively in case 5, and tumor invasion of a section of the small intestine was discovered during the operation. Considering the high risk of the combined operations in the same period, OPCAB + colorectal cancer resection + affected small intestinal resection + descending colostomy were performed in the first stage, and then the colon was anastomosed after the patient’s condition was improved. In addition, wound infection and treatment are also issues that need to be considered. The incidence of incision infection and mediastinal infection may be reduced by closing the thoracic incision first, re-disinfecting strictly and then performing the gastrointestinal surgery, isolating the thoracoabdominal incision, and prophylactic use of antibiotics prior to the operation. Timely reoperation for debridement, colostomy and omentum packing is conducive to early wound healing and effective control of mediastinal infection 10, 15.
This study still has some limitations. Firstly, because this study is a retrospective analysis and the number of included cases is small, there is a certain bias. Secondly, due to the limitation of the length of follow-up, the long-term effect of the concurrent surgery needs to be further followed up and observed. Additional in-depth studies are necessary to provided more solid evidence.
In summary, for the treatment of patients with gastrointestinal tumors and severe coronary heart disease, concurrent surgery is being accepted by a growing number of surgeons. This study provides a useful exploration of treatment strategies for patients with gastrointestinal tumors and severe coronary heart disease.