Intracerebral hemorrhage is a common and devastating disease, which requires improved treatment. Surgical treatment of supratentorial intracranial hematoma has the advantages [28] of reducing intracranial pressure, preventing herniation, eliminating the source of hemorrhage, reducing the source of localized mass lesions, and mitigating secondary neuro-inflammatory cascades. Although clinical guidelines [29] for intracranial hemorrhage are widely used, accompanying factors [30, 31] such as patient age, the Glasgow Coma Scale (GCS) score at admission, and hematoma volume, depth and location, usually influence the neurosurgeon’s decision regarding surgical treatment. Currently, there are many surgical procedures for treating intracranial hematoma, including traditional craniotomy, stereotactic aspiration, and endoscopic surgery. Compared with craniotomy, endoscopic surgery has direct vision and less damage to the surrounding normal brain tissue, and is highly recommended by many neurosurgeons [32]. However, indiscriminate restriction of the ICH indication based solely on dominance criteria could reduce the odds of patient survival in some cases.
The main complications of ICH are re-bleeding, intracranial infection, and pulmonary infection. In this study, the observation group’s incidence of postoperative complications was noticeably lower than that of the control group. The main reasons were analyzed as follows: (1) the traditional craniotomy is more traumatic and causes irreversible damage to the brain tissue and blood vessels in a fistula. Neuroendoscopic surgery is more consistent with the concept of minimally invasive surgery and can effectively avoid important brain functional areas. (2) Craniotomy adopts exterior lighting that is not bright enough for deep hematoma, while neuroendoscopy uses internal lighting, which allows for close observation. The brightness remains unchanged even with the changes in the hematoma depth, which improves the procedure’s accuracy by clearly displaying the intraoperative condition. (3) The infection risk is reduced due to the short operation time, small incision, and minor brain tissue damage.
A systematic review published in 2017 noted [27] that patients with ICH may benefit more from endoscopic surgery than from craniotomy, which supports the current study. In comparison to craniotomy, neuroendoscopic surgery has the advantages of higher hematoma evacuation rate, shorter operation time, better prognosis, and lower mortality.
However, some data included in this analysis were incorrect, such as data regarding patients with rebleeding (NE vs. C, 1 vs. 3) in Cho’s study [10] and death in Feng’s study [12] (NE vs. C, 6 vs. 8), although this did not affect the overall results. Furthermore, this study provided a different point of view in terms of re-bleeding and hospital stay duration; in addition, we also assessed the incidence of shunt surgery and the improvement of postoperative BI, GOS and GCS score, hospital costs, etc., for patients who administered neuroendoscopic surgery or craniotomy, adding new findings into this study. Endoscopic craniotomy with small bone window does not require the use of artificial materials (such as artificial dura mater) that are necessary for an operation and is not subject to secondary cranioplasty, hospitalization therefore cost less. In conclusion, this may serve as a constructive guideline for neurosurgeons in selecting the surgical procedure for treating intracranial hemorrhage. We found that endoscopic surgery, as opposed to craniotomy, can improve patient prognosis.
In this review, statistical heterogeneity was found between endoscopic surgery and craniotomy, in terms of operation time, hematoma residual volume, intraoperative blood loss, and hematoma evacuation, so a random-effects model and the jack-knife method were used to analyze pooled data with high heterogeneity.
In this review, statistical heterogeneity was found between endoscopic surgery and craniotomy in terms of operation time, hematoma residual volume, intraoperative blood loss, and hematoma evacuation, so a random-effect model and the jack-knife method were used to analyze pooled data with high heterogeneity.
For operative time analysis, when the studies by Cho and Feng [10, 12] in RCTs were excluded, further analysis showed that there was no heterogeneity (P = 0.85; I2 = 0%). But heterogeneity remained in the non-RCT group and the overall group; similar results were obtained for the overall effect (data not shown). When compared to the traditional craniotomy, neuroendoscopic surgery has the advantages of small incision and simple operation with the endoscopic working channel, thus reducing the operation time.
Neuroendoscopic minimally invasive surgery with small incision and small opening of bone window can effectively reduce traumatic injuries to patients. A clear surgical field helps prevent damage to normal tissues surrounding a lesion, shorten the operation time, avoid brain tissue being massively exposed for a long period of time, reduce stress reactions, and lower the risk of cerebral edema. The hematoma can be precisely located and effectively removed using neuroendoscopic observation in conjunction with CT positioning, and the removal process is regulated and safer with constant speed, which is beneficial to lower the risk of reperfusion injury and protect cerebral vessels and cranial nerve tissue.
The more the residual hematoma during operation, the worse the operative outcome. We found that there was no statistical heterogeneity for hematoma residual volume in non-RCTs (p = 0.61; I2 = 0%) after excluding Li Y’s study [21] and different results were observed for the overall effect. NE had a higher evacuation rate compared with the craniotomy groups, with SMD = − 0.59 (95%CI − 0.92 to − 0.26, p = 0.0005) (data not shown).
Theoretically, massive intraoperative blood loss may lead to hypoproteinemia or anemia after surgery. We found that the rate of hypoproteinemia after NE was lower than upon craniotomy,with no statistical heterogeneity for intraoperative blood loss volume in non-RCTs (p = 0.65; I2 = 0%) after excluding Xu’s study [23]. However, heterogeneity remained in the overall population; similar results were found for the overall effect, with SMD = − 3.00 (95%CI − 4.20 to − 1.80, p < 0.00001) (data not shown).
Enlargement of intracerebral hemorrhage is the main cause of early clinical deterioration. About 20–40% of the patients show hematoma re-expansion within the first 24h after hemorrhage [33]. Large amounts of hematoma are one of the causes of poor prognosis and high mortality. Previous findings indicate that NE has a high evacuation rate, from 79.2 to 99%, with significant difference compared with craniotomy [12, 26, 34, 35]. Theoretically, surgical hematoma evacuation would benefit patients. We used the jack-knife method to perform sensitivity analysis in the hematoma evacuation group. Therefore, the meta-analysis was repeated four and five times, respectively, each omitting a different study; finally, there was no statistical significance after excluding Zhang J’s article [13] in the RCT group and Zhu or Eroglu’s article [16, 22] in the non-RCT group. However,the same results were obtained for the overall effect (data not shown).
A possible reason for heterogeneity is that this study included multicenter trials, with differences in surgical procedures and treatments in many countries or different hospitals in the same country potentially leading to heterogeneity. We performed two subgroup analyses according to country and publication year, for preoperative Glasgow Coma Scale score and hematoma volume, and similar results were obtained in this work (data not shown).
In this study,the total rebleeding rate was significantly lower in the endoscopy group (3.5%; 8/227) compared with the craniotomy group (9.3%; 21/226), in disagreement with a previous publication [27] (2017). In addition, we assessed complications, including the rates of rebleeding, wound and intracranial infection, epilepsy, pneumonia, digestive tract disease, tracheotomy, hypoproteinemia, and shunt surgery respectively, as well as the incidence of total complications. There was no significant heterogeneity among articles, with I2 = 0% (p = 1.0) in total complications. In the NE group, 8.0% (84/1051) of patients had complications, while 18.7% (199/1066) was found in the craniotomy group. Pooled analysis showed that occurrence of total complications between the NE and craniotomy groups showed a significant difference (p < 0.00001, data not shown). The higher complications in the craniotomy group may be due to longer operation time, larger damage and elevated blood loss.
The cost for treating ICH was reported to be high, up to more than $44,000 in the first year of treatment alone [36]. In the current trials, NE incurred less hospital expenses compared with craniotomy due to shorter hospital stay, lower rate of complications, shorter operation time and better recovery in the latter procedure.
Zhang [13] mentioned that SP (serum substance P) and IL-2 levels in the NE group are significantly higher than control values four weeks after the operation, while IL-6, hs-CRP (high sensitive C-reactive protein), TNF-α (tumor necrosis factor-α) and SF (serum ferritin) levels are significantly lower compared with the craniotomy group. These results showed that endoscopic surgery effectively promotes the recovery of damaged glial cells and is helpful for the prognostic rehabilitation of patients.
The findings show that minimally invasive neuroendoscopic surgery can effectively lower the risk of complications, promote the recovery of neurological function, and improve patients’ life quality. This may be attributed to the minor harm that minimally invasive neuroendoscopic surgery causes to brain tissue. Brain tissue can avoid being massively exposed for a long period of time due to small incision, tiny bone foramen, and short operation time, thus reducing the chance of intracranial and pulmonary infections, intracranial re-bleeding, upper gastrointestinal hemorrhage, and other complications, effectively relieving brain tissue damage caused by cerebral hemorrhage and cerebral edema as well as decreasing the risk of death. Moreover, minimally invasive surgery can effectively reduce the stress stimulation of surgical operation on a body, lessen the pathological damage to brain tissue, relieve the pain of patients, shorten the ICU stay length and speed up the recovery of the patient's neurological function, thus improving the patient’s life quality [37,38,39].
In addition, different surgical approaches may improve the outcome of patients with ICH [40]. Based on previous reports and our own experience, we believe that a single surgical procedure cannot be fully adapted to all patients, and the procedure should be selected dialectically. Endoscopic surgery combined with stereotactic navigation, 3D reconstruction, intraoperative CT imaging, B-ultrasound or other techniques may cause more patients to benefit from this operation [41,42,43].
Limitations of this meta-analysis must be pointed out. Firstly, some of the included trials were non-RCTs, and most studies did not report random sequence generation and allocation concealment. Secondly, the duration of follow-up differed in these studies. Therefore, more studies addressing complications, good recovery, and mortality with uniform follow-up times of at least 6 months are required. Thirdly, the number of included patients was relatively limited in this review, which may affect the obtained results. Furthermore, heterogeneity was found in the pooled data for operation time,evacuation rate, residual hematoma volume and intraoperative blood loss volume, and a random-effects model was used to estimate the overall effects more conservatively.