Effects of intraoperative hypotension applied in aneurysm surgery on post-operative end organ damage

Intracranial aneurysms have long been associated with high mortality rates and low treatment success rates. Although this situation has changed in recent times, complications arising postoperatively and high mortality rates remain significant issues. Various clinical and radiological classifications have been developed for the diagnosis of patients with aneurysms and for planning appropriate approaches to their management. Traditional methods of treatment include clipping the aneurysm and, since the 1990s, endovascular approaches have also become widely accepted. Complications such as rebleeding, ischemia, infarction, renal damage, and infection may arise postoperatively, which can reduce treatment success. Cerebral ischemia is one of the major problems in the postoperative management of patients undergoing aneurysm surgery. In the past, up until the last 10 years, the 3H treatment (hypervolemia, hypernatremia, and hemodilution) was recommended for this complication, but nowadays, this is advocated as a normovolemic hemodynamic approach. The potential development of renal damage is hypothesized to be based on the contrast agents used in preoperative contrast-enhanced brain CT angiography or digital subtraction angiography (DSA) and anesthetic managements. Additionally, pre-existing kidney and liver damage in a patient worsen brain parenchymal damage following aneurysm rupture. Therefore, prophylactic measures have been considered to prevent these complications, and it has been suggested that intraoperative hypotension may lead to these injuries postoperatively and adversely affect the treatment process. Another significant factor affecting the treatment process is the use of temporary clips. As an alternative, the hypothesis of cardiac arrest induced by adenosine has been proposed. Although similar results are obtained compared to temporary clipping in aneurysm surgery, the use of this method is limited in cases of cardiac arrhythmias, posterior circulation aneurysms, and multiple aneurysms. In our study, we comparatively evaluated the effects of intraoperative hypotension and the use of temporary clips on postoperative damage, considering the patients' preoperative clinical condition. Despite the duration of both parameters being above average, we found that the application of temporary clips and hypotension had very limited effects on postoperative organ damage and prognosis. As a result of this evaluation, we determined that surgical methods do not directly affect the postoperative clinical condition of patients regardless of their preoperative clinical condition. In conclusion, we identified that the main determinant of a patient's postoperative clinical condition is their preoperative clinical condition, amount of bleeding, and additional medical history. Regardless of these determining factors, it is not possible to say that surgical methods (hypotension and temporary clipping) directly affect the postoperative clinical condition of patients.