Abstract
Background
Lower limb ischemia is a critical complication of femoral cannulation during minimally invasive and robot-assisted cardiac surgery. We aimed to evaluate the validity of our intraoperative near-infrared spectroscopy (NIRS) monitoring strategy and identify risk factors for distal perfusion.
Methods
We retrospectively analyzed 329 patients who underwent minimally invasive or robotic-assisted cardiac surgery with ipsilateral femoral arteriovenous cannulation between 2014 and June 2025. The primary outcome was intraoperative Tissue oxygenation index (TOI) desaturation requiring distal perfusion, defined as a >10% decline from baseline in the cannulated limb. Femoral artery (FA) diameter and femoral vein (FV) cross-sectional area were measured on preoperative computed tomography (CT). Risk factors were assessed by logistic regression, and receiver operating characteristic (ROC) analysis determined optimal cut-off values.
Results
Intraoperative TOI desaturation requiring distal perfusion occurred in 34 patients (10.3%). Multivariable analysis revealed that age (P=0.03) and FA-cannula diameter difference (P<0.001) were independent predictors. The optimal FA-cannula diameter difference cut-off was 1.7 mm. No postoperative limb complications occurred, and postoperative enzyme levels were not elevated in those requiring distal perfusion.
Conclusions
A smaller FA-cannula diameter difference and younger age independently predicted intraoperative lower limb ischemia. NIRS-guided distal perfusion may be a safe and effective strategy to prevent ischemic complications.
Keywords: Femoral cannulation, near-infrared spectroscopy (NIRS), lower limb ischemia, minimally invasive cardiac surgery (MICS), robotic-assisted cardiac surgery
Highlight box.
Key findings
• A smaller femoral artery (FA)-cannula diameter difference and younger age were independent predictors of intraoperative tissue oxygenation desaturation.
• Near-infrared spectroscopy (NIRS)-guided distal perfusion effectively prevented postoperative limb ischemic complications.
What is known and what is new?
• Lower limb ischemia is a recognized complication of femoral cannulation during minimally invasive and robotic cardiac surgery, and distal perfusion is commonly used as a preventive strategy.
• This study identifies a simple, preoperatively assessable anatomical parameter, the FA-cannula diameter difference, as a strong predictor of intraoperative ischemia detected by NIRS monitoring.
What is the implication, and what should change now?
• Preoperative assessment of FA size relative to cannula diameter may help identify patients at higher risk of intraoperative lower limb ischemia.
• Routine NIRS monitoring with timely distal perfusion may enhance the safety of femoral cannulation in minimally invasive and robotic cardiac surgery.
Introduction
Lower limb ischemia is a serious complication associated with femoral cannulation during minimally invasive cardiac surgery (MICS) and robot-assisted cardiac surgery (1-3). In the setting of procedures intended to be minimally invasive, lower limb ischemia should be regarded as a clinical catastrophe. Moreover, a previous study found that acute lower limb ischemia after cardiovascular surgery was associated with a significant risk for amputation and reduced long-term survival (4).
Near-infrared spectroscopy (NIRS) has been reported as a useful tool for assessing peripheral perfusion status by monitoring regional saturation of oxygen during cardiopulmonary bypass (CPB) (5). In cerebral and general NIRS monitoring, a regional oxygen saturation below 50% or a relative decrease of more than 20% from baseline has been reported as an intervention trigger (6,7). However, in lower limb monitoring during CPB, no widely accepted cut-off value has been established.
When signs of limb ischemia were detected by NIRS, distal perfusion via cannulation beyond the arterial line insertion site was often considered (8). At our institution, when intraoperative NIRS-derived tissue oxygenation index (TOI) in the cannulated limb continuously decreases by more than 10% from baseline observed immediately after CPB, a 4-Fr sheath is inserted for distal perfusion as a preventive measure.
In this study, we aimed to evaluate the validity of our intraoperative NIRS monitoring strategy in patients undergoing MICS and robot-assisted cardiac surgery, and to investigate the risk factors associated with the need for distal perfusion. We present this article in accordance with the STROBE reporting checklist (available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-1653/rc).
Methods
Ethics statement
This study did not involve the collection or storage of patient data or biological materials for multiple or indefinite use, and no third-party managed databases or biobanks were utilized. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Osaka Metropolitan University Institutional Review Board (reference No. 2025-082). Informed consent was taken from all the patients.
Study cohort and data collection
The institutional surgical database retrospectively included 393 patients who underwent MICS or robot-assisted cardiac surgery at Osaka Metropolitan University Hospital between 2014 and June 2025. Inclusion criteria were the establishment of CPB via femoral arteriovenous cannulation. 11 patients in whom both arterial and venous cannulas were inserted into the contralateral femoral vessels, 37 patients in whom cannulation involved both femoral arteries (FAs), as well as 16 patients with additional subclavian artery cannulation, were excluded. Consequently, 329 patients with ipsilateral femoral arteriovenous cannulation were included in the study cohort (Figure 1).
Figure 1.
Study flow diagram. Excluded cases: cannulation via the contralateral femoral vessels, both FAs, and the subclavian artery. FA, femoral artery; MICS, minimally invasive cardiac surgery.
Patient background
The patients’ baseline characteristics are presented in Table 1. The cohort consisted predominantly of patients undergoing mitral valve surgery, with robotic-assisted approaches used in approximately two-thirds of cases.
Table 1. Characteristics of study participants and outcomes.
| Variables | Study participants (n=329) |
|---|---|
| Age (years) | 62 [52, 72] |
| BSA (m2) | 1.67 [1.50, 1.81] |
| Male | 208 (63.2) |
| NYHA class 3 or 4 | 11 (3.3) |
| Hypertension | 166 (50.5) |
| Dyslipidemia | 84 (25.5) |
| Diabetes mellitus | 27 (8.2) |
| Old cerebral infarction | 18 (5.5) |
| Obstructive ventilatory defect (FEV1/FVC ratio <70%) | 44 (13.4) |
| CKD without dialysis (Cre >1.5 mg/dL) | 9 (2.7) |
| Dialysis | 2 (0.6) |
| Liver cirrhosis | 3 (0.9) |
| Autoimmune disease | 8 (2.4) |
| Thyroid dysfunction | 16 (4.9) |
| Active endocarditis | 3 (0.9) |
| Malignant disease controlled <5 years | 20 (6.1) |
| PVD | 0 (0.0) |
| Previous open-heart surgery | 2 (0.6) |
| Atrial fibrillation | 70 (21.3) |
| Old MI | 14 (4.3) |
| Operation details | |
| Robot-assisted cardiac surgery | 219 (66.6) |
| MICS | 109 (33.1) |
| Right trans-axillary thoracotomy | 90 (27.4) |
| Right anterolateral thoracotomy | 19 (5.8) |
| Partial sternotomy | 1 (0.3) |
| Mitral valve surgery | 255 (77.5) |
| Tricuspid valve surgery | 63 (19.1) |
| Maze procedure | 47 (14.3) |
| Aortic valve surgery | 49 (14.9) |
| ASD/PFO closure | 55 (16.7) |
| VSD closure | 1 (0.3) |
| Intraoperative variables | |
| Operative time (min) | 289 [252, 355] |
| CPB time (min) | 188 [155, 224] |
| Aortic cross-clamp time (min) | 126 [99, 160] |
| Hemoglobin on operating room entry (g/dL) | 13.0 [11.7, 14.1] |
| Hemoglobin immediately after CPB initiation (g/dL) | 7.9 [7.1, 8.9] |
| FA | |
| Femoral arterial cannula size (mm) | 6.0 [6.0, 6.7] |
| FA diameter at cannulation (mm) | 8.2 [7.5, 9.1] |
| FA-cannula diameter difference (mm) | 1.9 [1.5, 2.6] |
| FV | |
| Femoral venous cannula size (mm) | 7.3 [7.0, 8.3] |
| FV shortest diameter at cannulation (mm) | 9.6 [8.2, 11.1] |
| FV longest diameter at cannulation (mm) | 12.7 [11.2, 14.4] |
| FV cross-sectional area (mm2) | 94.7 [71.9, 124.2] |
| Ratio of FV to cannula cross-sectional area | 2.2 [1.7, 2.7] |
| Outcomes | |
| Distal perfusion | 34 (10.3) |
| Intraoperative FA repair | 1 (0.3) |
| Lower limb ischemia | 0 (0.0) |
| The maximum of postoperative CK (U/L) | 1,816 [1,212, 2,884] |
| The maximum of postoperative LD (U/L) | 435 [359, 537] |
Continuous variables are presented as median [IQR], whereas categorical variables are presented as number (%). ASD, atrial septal defect; BSA, body surface area; CK, serum creatinine kinase level; CKD, chronic kidney disease; CPB, cardiopulmonary bypass; Cre, serum creatinine level; FA, femoral artery; FEV1, forced expiratory volume in 1 second; FV, femoral vein; FVC, forced vital capacity; IQR, interquartile range; LD, serum lactate dehydrogenase level; MI, myocardial infarction; MICS, minimally invasive cardiac surgery; NYHA, New York Heart Association; PFO, patent foramen ovale; PVD, peripheral vessel disease; VSD, ventricular septal defect.
Endpoints and definitions
The primary endpoint of this study was defined as the occurrence of intraoperative TOI desaturation requiring distal perfusion, which was regarded as evidence of lower limb ischemia. Secondary endpoints included the presence of postoperative symptomatic lower limb ischemia and postoperative laboratory findings (creatinine kinase and lactate dehydrogenase).
The diameters of the FA and femoral vein (FV) were measured preoperatively using enhanced computed tomography (CT). For the FA, the shortest diameter of the circular vessel was used. The FA-cannula diameter difference was calculated as the vessel diameter at the cannulation site minus the cannula size. For the FV, which typically has an elliptical shape, the longest and shortest diameters were measured, and its cross-sectional area was calculated. The ratio of FV to cannula cross-sectional area was defined as the cross-sectional area of the FV divided by that of the venous cannula.
Also, the size of the femoral arterial cannula for CPB was determined preoperatively based on the estimated blood flow requirements calculated from the patient’s body surface area (BSA). The need for additional cannulation sites, such as the contralateral FA or the subclavian artery, was discussed preoperatively, and the final decision was made by the institutional heart team comprising perfusionists and surgeons. In practice, the cannulation site was selected to avoid segments with significant stenosis, intimal plaque, and calcification, based on preoperative CT imaging and intraoperative assessment. If the FA was unsuitable for cannulation, alternative cannulation sites were selected. Cannulation of the FA and FV was performed through open puncture, and hemostasis was secured with surgical sutures. Cannula size, usually expressed in French (Fr), was converted into millimeters using the formula 3 Fr = 1 mm.
NIRS measurement
NIRO-200NX (Hamamatsu Photonics, Hamamatsu, Japan) (Figure S1) was used to evaluate intraoperative local oxygen supply. It can continuously measure the TOI and quickly reflect changes in blood flow (9). By placing probes on both patients’ lower legs, real-time TOI measurements of both limbs were obtained.
Intraoperative perfusion management
All procedures were performed using transthoracic aortic cross-clamping. During CPB, pump flow was maintained between 2.2 and 2.6 L/min/m2 according to the institutional protocol. Mean arterial pressure was maintained between 60 and 80 mmHg. Pre-oxygenator and post-oxygenator pressures were kept below 350 and 250 mmHg, respectively. Hemoglobin concentration during CPB was adjusted to a target range of 8–10 g/dL to ensure adequate systemic oxygen delivery. The lowest body temperature during CPB was maintained at approximately 32 ℃.
Statistical analysis
Categorical data were expressed as frequencies and proportions and compared using the Chi-squared test or Fisher’s exact test as appropriate. Meanwhile, continuous variables were expressed as median with interquartile range (IQR); unpaired data were compared using the Mann-Whitney U test for non-parametric analysis. Perioperative complications were summarized as frequencies and compared using Fisher’s exact test. Risk factors for the need of distal perfusion were assessed by univariable and multivariable logistic regression analyses, and outcomes measured as continuous variables were analyzed using linear regression. For continuous variables, the optimal cut-off values were determined by receiver operating characteristic (ROC) curve analysis using the Youden index (maximum sum of sensitivity and specificity) (10). Statistical significance was defined as two-sided P<0.05. All P values may not be interpreted as confirmatory but descriptive. The R software version 4.3.1 (The R Foundation for Statistical Computing, Vienna, Austria) was used to conduct statistical analyses.
Results
Intraoperative findings
The median CPB time was 188 (IQR, 155–224) minutes. Intraoperative TOI desaturation requiring distal perfusion occurred in 34 patients (10.3%). Preoperative CT revealed a median FA diameter of 8.2 (IQR, 7.5–9.1) mm and a median ipsilateral FV cross-sectional area of 94.7 (IQR, 71.9–124.2) mm2 at the planned cannulation sites. Also, the actual median cannula sizes inserted were 6.0 (IQR, 6.0–6.7) mm for femoral arterial cannulation and 7.3 (IQR, 7.0–8.3) mm for femoral venous cannulation. Consequently, the FA-cannula diameter difference was 1.9 (IQR, 1.5–2.6) mm, and the ratio of FV to cannula cross-sectional area was 2.2 (IQR, 1.7–2.7).
Predictors of lower limb ischemia
The results of univariable and multivariable logistic regression analyses identifying risk factors for intraoperative TOI desaturation requiring distal perfusion, defined as lower limb ischemia, are summarized in Table 2. Univariable logistic regression analysis identified age, preoperative hypertension, FA-cannula diameter difference, and the ratio of FV to cannula cross-sectional area as potential predictors. In contrast, hemoglobin levels measured on operating room entry and immediately after CPB initiation were not significantly associated with the endpoint. Interaction analyses revealed significant interactions between age and preoperative hypertension [odds ratio (OR) =1.11; P=0.02] and between age and FA-cannula diameter difference (OR =0.943; P=0.03) (Table S1). Due to the limited number of outcomes (n=34), the final multivariable model was restricted to three clinically relevant predictors to minimize the risk of overfitting. Thus, because of collinearity between age and preoperative hypertension, preoperative hypertension was excluded in the final model. Multivariable logistic regression analysis identified age (OR =0.970; P=0.03) and FA-cannula diameter difference (OR =0.261; P<0.001) as independent predictors.
Table 2. Predictors of lower limb ischemia.
| Variables | Univariate analysis | Multivariate analysis | |||
|---|---|---|---|---|---|
| OR (95% CI) | P value | OR (95% CI) | P value | ||
| Age | 0.969 (0.943–0.995) | 0.02 | 0.970 (0.944–0.996) | 0.03 | |
| Male | 0.933 (0.449–1.94) | 0.85 | |||
| BSA | 0.448 (0.074–2.70) | 0.38 | |||
| NYHA class 3 or 4 | 0.864 (0.107–6.96) | 0.89 | |||
| Hypertension | 0.316 (0.143–0.701) | 0.005 | |||
| Hypercholesterolemia | 1.06 (0.472–2.36) | 0.90 | |||
| Diabetes mellitus | 0.314 (0.041–2.38) | 0.26 | |||
| COPD (%FEV1 <70%) | 0.376 (0.087–1.63) | 0.19 | |||
| CVA | 1.09 (0.240–4.96) | 0.91 | |||
| CKD with no dialysis (Cre >1.5 mg/dL) | 1.09 (0.132–8.97) | 0.94 | |||
| Dialysis | 8.91 (0.544–146) | 0.13 | |||
| Liver cirrhosis | <0.001 | >0.99 | |||
| Autoimmune disease | <0.001 | >0.99 | |||
| Thyroid dysfunction | 0.566 (0.072–4.42) | 0.59 | |||
| Malignant disease controlled <5 years | 2.09 (0.746–5.85) | 0.16 | |||
| PVD | <0.001 | >0.99 | |||
| Atrial fibrillation | 2.32 (0.730–7.41) | 0.15 | |||
| OMI | <0.001 | >0.99 | |||
| CPB time | 1.00 (0.995–1.01) | 0.67 | |||
| Aortic cross-clamp time | 1.00 (0.993–1.01) | 0.87 | |||
| Hemoglobin on operating room entry | 1.03 (0.832–1.26) | 0.82 | |||
| Hemoglobin immediately after CPB initiation | 0.938 (0.712–1.24) | 0.65 | |||
| FA-cannula diameter difference | 0.254 (0.139–0.465) | <0.001 | 0.261 (0.140–0.488) | <0.001 | |
| Ratio of FV to cannula cross-sectional area | 0.583 (0.354–0.959) | 0.03 | 0.888 (0.513–1.54) | 0.67 | |
%FEV1, percentage of forced expiratory volume in 1 second; BSA, body surface area; CI, confidence interval; CKD, chronic kidney disease; COPD, chronic obstructive pulmonary disease; CPB, cardiopulmonary bypass; Cre, serum creatinine level; CVA, cerebrovascular accident; FA, femoral artery; FV, femoral vein; NYHA, New York Heart Association; OMI, old myocardial infarction; OR, odds ratio; PVD, peripheral vessel disease.
In the univariable model, cubic spline curves of the FA-cannula diameter difference were plotted (Figure 2A). The predicted probability increased sharply when the diameter difference decreased below 2.0 mm. The optimal cut-off value of the FA-cannula diameter difference was determined to be 1.7 mm by ROC curve analysis (Figure 2B), with an area under the curve of 0.753 [95% confidence interval (CI): 0.671–0.835]. At this threshold, the specificity and sensitivity were 0.735 and 0.631, respectively, with a positive predictive value of 0.187 and a negative predictive value of 0.954.
Figure 2.
Association between FA-cannula diameter difference and intraoperative TOI desaturation. (A) Univariable cubic spline curves of the FA-cannula diameter difference. The vertical axis indicates the predicted probability of intraoperative TOI desaturation. (B) ROC curve analysis for the FA-cannula diameter difference. The optimal cut-off value was determined to be 1.7 mm. AUC, area under the curve; CI, confidence interval; FA, femoral artery; ROC, receiver operating characteristic; TOI, tissue oxygenation index.
Similarly, in the univariable spline analysis of the ratio of FV to cannula cross-sectional area, the predicted probability increased as the ratio decreased (Figure S2).
In the multivariable spline analysis, patients were stratified into two age subgroups based on 60 years and further by the presence or absence of preoperative hypertension. In the ≥60 years old subgroup, there was no notable difference between hypertensive and non-hypertensive patients. In contrast, in the <60 years old subgroup, non-hypertensive patients exhibited a marked increase in predicted probability, whereas hypertensive patients showed a plateau across the range of FA-cannula diameter differences (Figure 3).
Figure 3.
Multivariable cubic spline curves of the FA-cannula diameter difference according to the presence (blue line) or absence (red line) of preoperative hypertension between two age subgroups: <60 years old group (left) or ≥60 years old group (right). The vertical axis indicates the predicted probability of intraoperative TOI desaturation. FA, femoral artery; TOI, tissue oxygenation index.
Postoperative outcomes
No patients experienced postoperative lower limb complications. The maximum postoperative creatine kinase level was comparable between patients with distal perfusion (median, 1,750 U/L; IQR, 1,359–2,567 U/L) and those without distal perfusion (median, 1,839 U/L; IQR, 1,186–2,887 U/L), with no significant difference (P=0.94) (Figure 4A). Similarly, the maximum postoperative lactate dehydrogenase levels were 376 (IQR, 346–488) U/L in the distal perfusion group and 443 (IQR, 361–541) U/L in the non-distal perfusion group, showing a trend toward lower values in the distal perfusion group (P=0.08) (Figure 4B).
Figure 4.
Box-and-whisker plots comparing the maximum postoperative levels of (A) CK and (B) LD. Values were comparable between patients who required distal perfusion (“1” in the X-axis) and those who did not (“0” in the X-axis). CK, serum creatinine kinase level; LD, serum lactate dehydrogenase level.
Discussion
In this study, we investigated the predictors of intraoperative lower limb ischemia, defined as TOI desaturation requiring distal perfusion during CPB. Univariable analysis suggested associations of age, preoperative hypertension, FA-cannula diameter difference, and the ratio of FV to cannula cross-sectional area. In multivariable analysis, younger age and a smaller FA-cannula diameter difference remained independent predictors.
NIRS has been increasingly used to detect lower limb ischemia during MICS with peripheral cannulation. Schachner et al. were among the first to demonstrate the feasibility of NIRS monitoring for assessing distal perfusion during CPB, showing that NIRS can provide early detection of compromised limb perfusion and guide timely intervention (11). Subsequent organ-specific studies have supported the utility of NIRS (5,12,13).
The mechanisms underlying TOI desaturation can be broadly divided into two categories (14,15). The first is ischemic desaturation, caused by a reduction in oxygenated hemoglobin delivery due to impaired arterial inflow. The second is congestive desaturation, resulting from increased deoxygenated hemoglobin caused by impaired venous drainage. Both mechanisms are clinically relevant and must be considered when interpreting intraoperative TOI changes.
All four potential risk factors identified in the univariable analysis are clinically important. Among them, the FA-cannula diameter difference is the most critical determinant of ischemic risk. By setting the cut-off value at 1.7 mm by ROC analysis, TOI desaturation can be anticipated, enabling proactive preparation for distal perfusion. The negative predictive value was 0.954, indicating that this threshold is a reliable indicator for ruling out ischemic events. Conversely, the positive predictive value was 0.187; nevertheless, it remains clinically important to be prepared for distal perfusion in cases below this threshold. A fair question is whether continuous monitoring of TOI and selective intervention is more demanding than routine distal perfusion in all patients. While prophylactic distal perfusion may prevent ischemia, it increases procedural complexity and complications. Given the high negative predictive value of the cut-off, this approach may represent a pragmatic balance between safety and invasiveness.
Interestingly, the absence of preoperative hypertension served as an effect modifier of age, significantly influencing its association with the outcome. This finding may be partly explained by the propensity for vascular spasm in patients without hypertensive or atherosclerotic changes. Vascular spasm has been widely attributed to vascular smooth muscle hyperreactivity and autonomic influences (16-18). Femoral cannulation itself may induce acute vasospasm, resulting in a functional reduction in arterial diameter that cannot be captured by preoperative CT measurements. In contrast, chronic arterial remodeling and diminished vascular reactivity in hypertensive elderly patients may reduce their susceptibility to acute vasospasm during cannulation (19-21). Normotensive younger patients with relatively compliant arteries might be more susceptible to catheter-induced vascular spasm, which could compromise distal perfusion despite the absence of structural narrowing. On the other hand, younger hypertensive patients did not require distal perfusion despite a smaller FA-cannula diameter difference. This might be related to the perfusion pressure during CPB; however, given the small sample size, these observations should be interpreted with caution.
Furthermore, although the ratio of FV to cannula cross-sectional area was not an independent predictor, it may contribute to congestive TOI desaturation. From a practical standpoint, venous cannulation strategies using an additional jugular venous cannula could allow the use of a smaller FV cannula and may help reduce venous congestion.
Postoperative outcomes further support our intraoperative management strategy. Serum creatine kinase and lactate dehydrogenase levels are reliable markers associated with lower limb ischemia, indicating muscular injury and ischemia-reperfusion effects (22,23). The maximum postoperative creatine kinase and lactate dehydrogenase values were not elevated in patients who required distal perfusion; in fact, there was a trend toward lower lactate dehydrogenase levels in this group. These findings suggest that our strategy of performing distal perfusion based on TOI monitoring may be safe and effective.
Several limitations should be acknowledged. First, this study was a retrospective, single-center study with a limited sample size. Second, the FA diameter measured on preoperative CT did not always correspond precisely to the actual insertion site, and FV measurements may have been influenced by hemodynamic conditions at the time of imaging. Third, patient selection bias was inevitable, as patients with extremely small FA diameters often underwent cannulation using additional arterial cannulation or alternative arterial sites; such patients were excluded from the study. In addition, as TOI desaturation requiring distal perfusion was used as the outcome, the findings are inherently dependent on the monitoring device and the threshold applied, which may limit reproducibility across institutions. Furthermore, because this was a retrospective study and continuous intraoperative TOI waveform data were not available for review, we were unable to verify whether desaturation events were caused by ischemic or congestive mechanisms. Similarly, detailed time-course data of intraoperative perfusion pressure, hemoglobin concentration, and vasoactive or inotropic agent use during CPB were not available. However, as described in the methods section, systemic perfusion parameters and hemoglobin levels were managed within institutional target ranges throughout CPB, and therefore, the impact of these unadjusted variables on the present findings is considered limited. Finally, historical bias and learning-curve effect during the observational period could not be fully excluded.
Conclusions
Intraoperative lower limb ischemia during MICS and robotic-assisted cardiac surgery was independently associated with a smaller FA-cannula diameter difference and younger age. Furthermore, our distal perfusion strategy based on TOI monitoring may be a safe and effective approach to prevent ischemic complications. However, further comparative studies including patients with similar risk factors who did not undergo distal perfusion are needed to confirm the clinical benefit of this strategy.
Supplementary
The article’s supplementary files as
Acknowledgments
We would like to thank the clinical research coordinators in the Osaka Metropolitan University Institutional Review Board.
Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Osaka Metropolitan University Institutional Review Board (reference No. 2025-082). Informed consent was taken from all the patients.
Footnotes
Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-1653/rc
Funding: None.
Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-1653/coif). The authors have no conflicts of interest to declare.
Data Sharing Statement
Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-1653/dss
References
- 1.Gander JW, Fisher JC, Reichstein AR, et al. Limb ischemia after common femoral artery cannulation for venoarterial extracorporeal membrane oxygenation: an unresolved problem. J Pediatr Surg 2010;45:2136-40. 10.1016/j.jpedsurg.2010.07.005 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Bisdas T, Beutel G, Warnecke G, et al. Vascular complications in patients undergoing femoral cannulation for extracorporeal membrane oxygenation support. Ann Thorac Surg 2011;92:626-31. 10.1016/j.athoracsur.2011.02.018 [DOI] [PubMed] [Google Scholar]
- 3.Gates JD, Bichell DP, Rizzo RJ, et al. Thigh ischemia complicating femoral vessel cannulation for cardiopulmonary bypass. Ann Thorac Surg 1996;61:730-3. 10.1016/0003-4975(95)00743-1 [DOI] [PubMed] [Google Scholar]
- 4.Indriani S, Dewangga R, Adiarto S, et al. Acute Limb Ischemia after Cardiovascular Surgery: A Deadly Duo Combination with High Mortality. Int J Angiol 2023;32:158-64. 10.1055/s-0043-1761290 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Toya T, Fujita T, Fukushima S, et al. Efficacy of regional saturation of oxygen monitor using near-infrared spectroscopy for lower limb ischemia during minimally invasive cardiac surgery. J Artif Organs 2018;21:420-6. 10.1007/s10047-018-1057-y [DOI] [PubMed] [Google Scholar]
- 6.Murkin JM, Adams SJ, Novick RJ, et al. Monitoring brain oxygen saturation during coronary bypass surgery: a randomized, prospective study. Anesth Analg 2007;104:51-8. 10.1213/01.ane.0000246814.29362.f4 [DOI] [PubMed] [Google Scholar]
- 7.Rad APP, Alizadeh P, Nourizadeh M, et al. Quantitative analysis of tissue oxygenation variability across anatomical landmarks in healthy individuals via near-infrared spectroscopy. Sci Rep 2025;15:37527. 10.1038/s41598-025-23102-y [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Shikata F, Nakamura Y, Okuzono Y, et al. Regional oxygen saturation change rate for detection of leg ischemia in minimally invasive cardiac surgery. Perfusion 2021;36:382-7. 10.1177/0267659120946723 [DOI] [PubMed] [Google Scholar]
- 9.Tanaka M, Umemoto Y, Ohashi W, et al. NIRO200NX: Reliable Monitoring System for Buried Deep Inferior Epigastric Perforator Flap. Plast Reconstr Surg Glob Open 2024;12:e6096. 10.1097/GOX.0000000000006096 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Ruopp MD, Perkins NJ, Whitcomb BW, et al. Youden Index and optimal cut-point estimated from observations affected by a lower limit of detection. Biom J 2008;50:419-30. 10.1002/bimj.200710415 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Schachner T, Bonaros N, Bonatti J, et al. Near infrared spectroscopy for controlling the quality of distal leg perfusion in remote access cardiopulmonary bypass. Eur J Cardiothorac Surg 2008;34:1253-4. 10.1016/j.ejcts.2008.08.027 [DOI] [PubMed] [Google Scholar]
- 12.Sun Q, Wu W. Effect of near-infrared spectroscopy on postoperative delirium in cardiac surgery with cardiopulmonary bypass: a systematic review and meta-analysis. Front Cardiovasc Med 2024;11:1404210. 10.3389/fcvm.2024.1404210 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Özyaprak B, Apaydın Y, Balk Ş, et al. Intraoperative Renal Near-Infrared Spectroscopy Monitoring as a Predictor of Renal Outcomes in Cardiac Surgery. Med Sci Monit 2025;31:e947462. 10.12659/MSM.947462 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Calderone A, Jarry S, Couture EJ, et al. Early Detection and Correction of Cerebral Desaturation With Noninvasive Oxy-Hemoglobin, Deoxy-Hemoglobin, and Total Hemoglobin in Cardiac Surgery: A Case Series. Anesth Analg 2022;135:1304-14. 10.1213/ANE.0000000000006155 [DOI] [PubMed] [Google Scholar]
- 15.Vranken NPA, Weerwind PW, Sutedja NA, et al. Cerebral Oximetry and Autoregulation during Cardiopulmonary Bypass: A Review. J Extra Corpor Technol 2017;49:182-91. [PMC free article] [PubMed] [Google Scholar]
- 16.Lanza GA, Careri G, Crea F. Mechanisms of coronary artery spasm. Circulation 2011;124:1774-82. 10.1161/CIRCULATIONAHA.111.037283 [DOI] [PubMed] [Google Scholar]
- 17.Franczyk B, Dybiec J, Frąk W, et al. Cellular Mechanisms of Coronary Artery Spasm. Biomedicines 2022;10:2349. 10.3390/biomedicines10102349 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Nishimiya K, Takahashi J, Oyama K, et al. Mechanisms of Coronary Artery Spasm. Eur Cardiol 2023;18:e39. 10.15420/ecr.2022.55 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19.Martinez-Quinones P, McCarthy CG, Watts SW, et al. Hypertension Induced Morphological and Physiological Changes in Cells of the Arterial Wall. Am J Hypertens 2018;31:1067-78. 10.1093/ajh/hpy083 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Schiffrin EL. Vascular remodeling in hypertension: mechanisms and treatment. Hypertension 2012;59:367-74. 10.1161/HYPERTENSIONAHA.111.187021 [DOI] [PubMed] [Google Scholar]
- 21.Ma J, Li Y, Yang X, et al. Signaling pathways in vascular function and hypertension: molecular mechanisms and therapeutic interventions. Signal Transduct Target Ther 2023;8:168. 10.1038/s41392-023-01430-7 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22.Cearra I, Herrero de la Parte B, Moreno-Franco DI, et al. A reproducible method for biochemical, histological and functional assessment of the effects of ischaemia-reperfusion syndrome in the lower limbs. Sci Rep 2021;11:19325. 10.1038/s41598-021-98887-9 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23.Watson JD, Gifford SM, Clouse WD. Biochemical markers of acute limb ischemia, rhabdomyolysis, and impact on limb salvage. Semin Vasc Surg 2014;27:176-81. 10.1053/j.semvascsurg.2015.01.007 [DOI] [PubMed] [Google Scholar]