The utility of intraoperative ultrasonography for spinal cord surgery.

OBJECTIVES: Intraoperative ultrasonography (IOUS) offers the advantage of providing real-time imaging features, yet it is not generally used. This study aims to discuss the benefits of utilizing IOUS in spinal cord surgery and review related literature. MATERIALS AND METHODS: Patients who underwent spinal cord surgery utilizing IOUS at a single institution were retrospectively collected and analyzed to evaluate the benefits derived from the use of IOUS. RESULTS: A total of 43 consecutive patients were analyzed. Schwannoma was the most common tumor (35%), followed by cavernous angioma (23%) and ependymoma (16%). IOUS confirmed tumor extent and location before dura opening in 42 patients (97.7%). It was particularly helpful for myelotomy in deep-seated intramedullary lesions to minimize neural injury in 13 patients (31.0% of 42 patients). IOUS also detected residual or hidden lesions in 3 patients (7.0%) and verified the absence of hematoma post-tumor removal in 23 patients (53.5%). In 3 patients (7.0%), confirming no intradural lesions after removing extradural tumors avoided additional dural incisions. IOUS identified surrounding blood vessels and detected dural defects in one patient (2.3%) respectively. CONCLUSIONS: The IOUS can be a valuable tool for spinal cord surgery in identifying the exact location of the pathologic lesions, confirming the completeness of surgery, and minimizing the risk of neural and vascular injury in a real-time fashion.

Comparison of Catheter Malposition Between Left and Right Ultrasound-Guided Infraclavicular Subclavian Venous Catheterizations: A Randomized Controlled Trial.

OBJECTIVES: Catheter malposition after subclavian venous catheterization (SVC) is not uncommon and can lead to serious complications. This study hypothesized that the left access is superior to the right access in terms of catheter malposition after ultrasound-guided infraclavicular SVC due to the asymmetry of the bilateral brachiocephalic veins. DESIGN: Parallel-armed randomized controlled trial. SETTING: A tertiary referral hospital in Korea. PATIENTS: Patients 20-79 years old who were scheduled to undergo SVC under general anesthesia. INTERVENTIONS: Patients were randomly assigned to either the left (n = 224) or right (n = 225) SVC group. The primary outcome measure was the overall catheter malposition rate. The secondary outcome measures included catheter malposition rates into the ipsilateral internal jugular and contralateral brachiocephalic veins, other catheterization-related complications, and catheterization performance. MEASUREMENTS AND MAIN RESULTS: The catheter malposition rate was lower (10 [4.5%] vs. 31 [13.8%], p = 0.001), especially in the ipsilateral internal jugular vein (9 [4.0%] vs. 24 [10.7%], p = 0.007), in the left SVC group than in the right SVC group. In the left SVC group, catheterization success rates on the first pass (88 [39.3%] vs. 65 [28.9%], p = 0.020) and first-catheterization attempt (198 [88.4%] vs. 181 [80.4%], p = 0.020) were higher whereas times for vein visualization (30 s [18-50] vs. 20 s [13-38], p < 0.001) and total catheterization (134 s [113-182] vs. 132 s [103-170], p = 0.034) were longer. There were no significant differences in other catheterization performance and catheterization-related complications between the two groups. CONCLUSIONS: These findings strengthen the rationale for choosing the left access over the right access for ultrasound-guided infraclavicular SVC.

Association Between High Preoperative White Blood Cell-to-Hemoglobin Ratio and Postoperative Symptomatic Cerebral Vasospasm in Patients With Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Cerebral vasospasm after aneurysmal subarachnoid hemorrhage (ASAH) is a serious complication and has a strong relationship with systemic inflammatory responses. Given previously reported relationships between leukocytosis and anemia with ASAH-related cerebral vasospasm, this study examined the association between the preoperative white blood cell-to-hemoglobin ratio (WHR) and postoperative symptomatic cerebral vasospasm (SCV) in patients with ASAH. METHODS: Demographic, preoperative (comorbidities, ASAH characteristics, laboratory findings), intraoperative (operation and anesthesia), and postoperative (SCV, other neurological complications, clinical course) data were retrospectively analyzed in patients with ASAH who underwent surgical or endovascular treatment of the culprit aneurysm. Patients were divided into high-WHR (n=286) and low-WHR (n=257) groups based on the optimal cutoff value of preoperative WHR (0.74), and stabilized inverse probability weighting was performed between the 2 groups. The predictive power of the WHR and other preoperative systemic inflammatory indices (neutrophil-to-albumin, neutrophil-to-lymphocyte, platelet-to-lymphocyte, platelet-to-neutrophil, platelet-to-white blood cell ratios, and systemic immune-inflammation index) for postoperative SCV was evaluated. RESULTS: Postoperative SCV was more frequent in the high-WHR group than in the low-WHR group before (33.2% vs. 12.8%; P<0.001) and after (29.4% vs. 19.1%; P=0.005) inverse probability weighting. Before weighting, the predictive power for postoperative SCV was the highest for the WHR among the preoperative systematic inflammatory indices investigated (area under receiver operating characteristics curve 0.66, P<0.001). After weighting, preoperative WHR ≥0.74 was independently associated with postoperative SCV (odds ratio 1.76; P=0.006). CONCLUSIONS: High preoperative WHR was an independent predictor of postoperative SCV in patients with ASAH.

The Warburg effect in patients with brain tumors: a comprehensive analysis of clinical significance.

PURPOSE: The Warburg Effect, referring to an elevation in serum lactate level attributable to increased tumor metabolism, is present in patients with brain tumors. This study comprehensively analyzes the Warburg effect in patients undergoing brain tumor resection. METHODS: We retrospectively analyzed the baseline intraoperative serum lactate levels of 2,053 patients who underwent craniotomies, including 415 with cerebral aneurysms and 1,638 with brain tumors. The brain tumor group was divided into subgroups based on the tumor pathology (extra-axial and intra-axial tumor) and the WHO tumor grade (high-grade and low-grade). RESULTS: Serum lactate level was significantly higher in the tumor group than in the aneurysm group (1.98 ± 0.97 vs. 1.09 ± 0.57 mmol/L, p < 0.001). The hyperlactatemia incidence (serum lactate level > 2.2 mmol/L) was higher in the tumor group (33.5 vs. 3.1%, p < 0.001). Severe hyperlactatemia (serum lactate level > 4.4 mmol/L) was found in 34 patients (2.1%) of only the tumor group. In patients with intra-axial tumors, serum lactate level was greater in high- than low-grade tumors (2.10 ± 1.05 vs. 1.88 ± 0.92 mmol/L, p = 0.006). Factors predictive of hyperlactatemia included supratentorial tumor location (odds ratio[95%CI] 2.926[2.127-4.025], p < 0.001) and a long tumor diameter (1.071[1.007-1.139], p = 0.028). In high-grade intra-axial brain tumor patients, there was a significant difference in overall survival between patients with hyperlactatemia than those without (p = 0.048). CONCLUSION: Our results show that brain tumor patients exhibit the Warburg effect and serum lactate may be a useful diagnostic and prognostic biomarker in patients with high-grade intra-axial brain tumors.

Preoperative platelet count may predict postoperative symptomatic cerebral hyperperfusion syndrome after superficial temporal artery-middle cerebral artery anastomosis in moyamoya patients.

OBJECTIVE: Platelets play a critical role in the inflammatory response, accompanied by microvascular endothelial dysfunction, underlying postoperative symptomatic cerebral hyperperfusion syndrome (PSCHS) after superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis in moyamoya patients. We examined whether the preoperative platelet count can predict PSCHS after STA-MCA anastomosis in such patients. METHODS: In 160 adult moyamoya patients undergoing 186 STA-MCA anastomoses, preoperative (demographics, initial clinical manifestation, and Suzuki grade), intraoperative (surgical time, operative side, fluid balance, and maximum and minimum mean blood pressure before and after vessel anastomosis), immediate postoperative (APACHE 2 score), and laboratory (hemoglobin and C-reactive protein levels and white blood cell and platelet counts) data were collected retrospectively. RESULTS: 84 patients (90 sides, 48.4 %) developed PSCHS with a median(IQR) onset of postoperative day 1(0-3) and duration of 4(3-7) days. The preoperative (25.2[22.8-28.0] vs. 23.1[19.7-26.2] ×104/µL, p = 0.009) platelet count was significantly higher in patients with PSCHS than in those without. The preoperative platelet count (odds ratio[95 % confidence interval], 1.14[1.03-1.27], p = 0.011), operation on the dominant hemisphere (6.84 [3.26-14.36], p < 0.001), and negative fluid balance (2.41[1.04-5.59], p = 0.040) were significant independent predictors of PSCHS. The optimal cut-off value for preoperative platelet count was 22.7 ×104/µL, and PSCHS developed more frequently in cases with a preoperative platelet count ≥ 22.7 × 104/µL (2.90[1.54-5.45]; p = 0.001). CONCLUSION: A high preoperative platelet count may be associated with the development of PSCHS after STA-MCA anastomosis in adult moyamoya patients.

Association Between Postoperative Body Temperature and All-Cause Mortality After Off-Pump Coronary Artery Bypass Graft Surgery: A Retrospective Observational Study.

BACKGROUND: Inadvertent perioperative hypothermia is common in patients undergoing off-pump coronary artery bypass grafting (OPCAB). We investigated the association between early postoperative body temperature and all-cause mortality in patients undergoing OPCAB. METHODS: We reviewed the electronic medical records of 1714 patients who underwent OPCAB (median duration of follow-up, 47 months). Patients were divided into 4 groups based on body temperature at the time of intensive care unit admission after surgery (moderate-to-severe hypothermia, <35.5°C; mild hypothermia, 35.5°C-36.5°C; normothermia, 36.5°C-37.5°C; and hyperthermia, ≥37.5°C). Cox proportional hazards models were used to assess the association between body temperature and all-cause mortality. The association between early postoperative changes in body temperature and all-cause mortality was also assessed by dividing the patients into 4 categories according to the body temperature measured at postoperative intensive care unit admission and the average body temperature during the first 3 postoperative days. RESULTS: Compared to the normothermia group, the adjusted hazard ratios of all-cause mortality were 2.030 (95% confidence interval, 1.407-2.930) in the moderate-to-severe hypothermia group and 1.445 (95% confidence interval, 1.113-1.874) in the mild hypothermia group. Patients who were hypothermic at postoperative intensive care unit admission but attained normothermia thereafter were at a lower risk of all-cause mortality compared to patients who did not regain normothermia (adjusted hazard ratio, 0.631; 95% confidence interval, 0.453-0.878), while they were still at a higher risk of all-cause mortality than those who were consistently normothermic (adjusted hazard ratio, 1.435; 95% confidence interval, 1.090-1.890). CONCLUSIONS: Even mild early postoperative hypothermia was associated with all-cause mortality after OPCAB. Patients who regained normothermia postoperatively were at lower risk of all-cause mortality compared to those who did not.

Lower intra-abdominal pressure has no cardiopulmonary benefits during laparoscopic colorectal surgery: a double-blind, randomized controlled trial.

BACKGROUND: Higher intra-abdominal pressure may impair cardiopulmonary functions during laparoscopic surgery. While 12-15 mmHg is generally recommended as a standard pressure, the benefits of lower intra-abdominal pressure are unclear. We thus studied whether the low intra-abdominal pressure compared with the standard pressure improves cardiopulmonary dynamics during laparoscopic surgery. METHODS: Patients were randomized according to the intra-abdominal pressure and neuromuscular blocking levels during laparoscopic colorectal surgery: low pressure (8 mmHg) with deep-block (post-tetanic count 1-2), standard pressure (12 mmHg) with deep-block, and standard pressure with moderate-block (train-of-four count 1-2) groups. During the laparoscopic procedure, we recorded cardiopulmonary variables including cardiac index, pulmonary compliance, and surgical conditions. We also assessed postoperative pain intensity and recovery time of bowel movement. The primary outcome was the cardiac index 30 min after onset of laparoscopy. RESULTS: Patients were included in the low pressure with deep-block (n = 44), standard pressure with deep-block (n = 44), and standard pressure with moderate-block (n = 43) groups. The mean (SD) of cardiac index 30 min after laparoscopy was 2.7 (0.7), 2.7 (0.9), and 2.6 (1.0) L min-1 m-2 in each group (P = 0.715). The pulmonary compliance was higher but the surgical condition was poorer in the low intra-abdominal pressure than the standard pressure (both P < 0.001). Other variables were comparable between groups. CONCLUSION: We observed few cardiopulmonary benefits but poor surgical conditions in the low intra-abdominal pressure during laparoscopy. Considering cardiopulmonary dynamics and surgical conditions, the standard intra-abdominal pressure may be preferable to the low pressure for laparoscopic surgery.

Association Between Elevated Echocardiographic Index of Left Ventricular Filling Pressure and Acute Kidney Injury After Off-Pump Coronary Artery Surgery.

BACKGROUND: The ratio of the early transmitral flow velocity to early diastolic velocity of the mitral annulus (E/e') is an echocardiographic index of mean left ventricular (LV) filling pressure. We investigated the association between the preoperative E/e' ratio and postoperative acute kidney injury (AKI) during off-pump coronary artery bypass surgery (OPCAB).Methods and Results:We reviewed 585 patients who underwent OPCAB and with preserved LV ejection fraction determined by preoperative echocardiography. AKI was determined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria. Multivariable logistic regression analysis was performed. E/e' was also analyzed as 3 categories (E/e' <8, 8≤E/e'≤15, and E/e' >15) and as a continuous variable. A propensity score analysis was used to match the patients with E/e' >15 and E/e' ≤15. A preoperative E/e' >15 was an independent predictor for AKI (odds ratio 3.01, 95% confidence interval 1.40-6.17). E/e' >15 was also an independent predictor for AKI when E/e' was analyzed with 3 categories or as a continuous variable. In the matched sample, the incidence of AKI and 1-year mortality was significantly higher in patients with E/e' >15. CONCLUSIONS: Among patients undergoing OPCAB with preserved LV systolic function, a preoperative E/e' ratio >15 was an independent predictor of postoperative AKI. Measurement of the preoperative E/e' ratio may help to assess the risk of postoperative AKI.