CARDIOVASCULAR JOURNAL OF AFRICA • Volume 33, No 3, May/June 2022 AFRICA 119 CABG and investigated the effect of SCT versus the doubleclamp technique (DCT) on postoperative stroke. Although there have been many studies investigating the effect of aortic cross-clamp techniques on postoperative stroke, to the best of our knowledge, we present one of the rare studies involving only octogenarians. Our study results showed that both techniques yielded similar outcomes regarding incidence of postoperative stroke in octogenarians undergoing open-heart surgery. Following open-heart surgery, neurological complications increase morbidity and mortality rates, leading to catastrophic results for some patients and surgeons. Advanced age has been shown to be an independent risk factor associated with increased mortality of up to 15.9% and increased morbidity rates.10 The incidence of postoperative stroke has been reported to be one to 5% in published studies, and this rate can increase up to 9% in patients aged 75 years and older.9,10 In the Framingham Heart Study, aortic calcification, as evidenced by imaging modalities, increased stroke risk 3.5-fold in 65-year-old and older patients.11 In the literature, there are studies recommending SCT for proximal and distal anastomoses in CABG to reduce neurological complications.10,12-14 Aranki et al.15 reported that SCT reduced in-hospital mortality and brain injury rates. In another study, Marshall et al.16 showed that the majority of embolisations occurred during aortic manipulation, particularly during removal of the aortic cross-clamp. Other authors also reported that the double clamp, on-pump strategy had a 2.5-fold increased risk of postoperative stroke compared with the SCT, even after controlling for epi-aortic grade.17 Regarding trends in aortic clamp use during CABG surgery and the effect of aortic clamping strategies on neurological outcomes, aortic cross-clamping and manipulation are known risk factors for neurological complications.18 The factors that increase stroke risk include atherosclerotic disease involving the ascending aorta and intra-operative hypoperfusion.19 Therefore, the less often that aortic cross-clamps are used, the more neurological complications are avoided. In a study, Us et al.15 observed no neurological complications with SCT, while the rate of neurological complications was significantly higher in patients in whom partial cross-clamping was applied. In addition, Güden et al.20 recommended using SCT to minimise possible aortic embolisation and prevent neurological complications in patients undergoing CABG. Conversely, Musumeci et al.21 found in their study that SCT was not effective in the prevention of myocardial ischaemia and neurological complications. McKhann et al.22 reported that previous cerebrovascular accidents and carotid lesions were the main risk factors for stroke after CABG. In another study, Grega et al.18 found the stroke rate to be 1.1 and 2.9% in patients undergoing SCT and DCT, respectively. In contrast to the hypothesis that the incidence of aortic embolism could be reduced by avoiding manipulation with a second clamp,23-26 the SCT has been proposed to prolong the cross-clamp time and open the closed system, leading to cardiac or cerebral air embolism risks.27 However, some authors who recommend using the SCT have claimed that this technique allows for a more uniform cardioplegic delivery during anastomosis of the grafts and immediate myocardial reperfusion when the crossclamp is released. Those who recommend using the DCT however have argued that none of the techniques are better than the early removal of the aortic cross-clamp and that DCT allows for the immediate use of the internal mammary artery for perfusion.28 SCT indicates only one potential factor and is overshadowed by the effects of other potential causes of stroke.28 More importantly, SCT itself does not solely explain cerebral protection and stroke, and a multifactorial approach is needed to prevent post-CABG stroke and cerebrovascular accidents. Embolic material might depend not only on the side-biting clamp but could also result from the cross-clamp itself, CPB-related jet perfusion, aortic cannulation, and aortic punch. None of these sources of emboli would be affected by the application of a sidebiting clamp.28 A study demonstrated that the investigation of atherosclerotic lesions through epi-aortic scanning before aortic manipulation and cannulation could be helpful to reduce stroke risk.29 In their study, Uyar et al.30 utilised intra-operative ultrasonography to detect plaques located in the ascending aorta and concluded that this was the best method for preventing neurological complications due to possible embolisations from the aorta. Previous studies have shown improved morbidity outcomes following off-pump CABG in high-risk patients with lower cardiac, pulmonary and renal complications and bleeding, shorter lengths of hospital stay, fewer neurological complications and lower costs.31 Conversely, Tugtekin et al.32 performed on- and off-pump CABG in 344 and 237 octogenarians, respectively. They found similar morbidity and mortality rates in both groups; however, lower morbidity in the on-pump CABG group was attributed to relatively short cross-clamping and perfusion times. In another study, prolonged aortic cross-clamp time was associated with unfavourable postoperative outcomes in elderly individuals.33 Due to the increased incidence of arteriosclerosis of the ascending aorta, neurological complications, such as CABGrelated stroke, are a major concern in octogenarians. During off-pump surgery, cross-clamping and aortic cannulation are avoided to reduce the stroke risk due to decreased manipulation of the ascending aorta. Off-pump surgery offers a no-touch technique and therefore reduces the incidence of stroke by 78%.27 In this study, 88 octogenarian patients underwent CABG with SCT (group 1) and 83 patients underwent CABG with MCT Table 3. Postoperative length of stay in hospital and intensive care unit Group 1 (n = 88) Mean ± SD (min–max) Group 2 (n = 83) Mean ± SD (min–max) Statistic of test; p-value Hospital stay, days 2.35 ± 0.72 (1–20) 2.45 ± 0.86 (1–22) U = 1300.0; 0.122 ICU stay, days 8.6 ± 1.07 (5–30) 6.70 ± 1.72 (6–31) U = 3130.7; 0.001** SD: standard deviation; ICU: intensive care unit. Table 4. Stroke and mortality rates Rates Group 1 (n = 88) Mean ± SD % Group 1 (n = 88) Mean ± SD % Statistic of test; p-value Stroke Yes No 1 87 1.13 98.8 1 82 1.2 98.7 χ 2 = 0.133; 1.000 Mortality Yes No 2 86 2.2 98.2 2 81 2.4 97.5 χ 2 = 0.008; 1.000 SD: standard deviation.
RkJQdWJsaXNoZXIy NDIzNzc=