Distal leg protection for peripheral cannulation in minimally invasive and totally endoscopic cardiac surgery

Utility of Ultrasonographic Assessment of Distal Femoral Arterial Flow during Minimally Invasive Valve Surgery

PURPOSE

To evaluate the utility of ultrasonographic assessment of blood flow to the lower limb below the cannulation site in minimally invasive cardiac surgery (MICS).

METHODS

Twenty-two patients who underwent ultrasonographic assessment in MICS were reviewed retrospectively. In all patients, the right femoral artery was used for arterial cannulation. Ultrasonographic assessment was performed using a 15-MHz ultrasonography small probe, and regional oxygen saturation was monitored by near-infrared spectroscopy (NIRS).

RESULTS

The mean flow velocity at the distal side of the cannulation site was 46.2 ± 25.4 cm/s. In six patients, a >40% decreased from baseline regional oxygen saturation was observed. In five of the six patients, the flow velocity was very slow, and spontaneous echo contrast was also observed in three cases. Their regional oxygen saturation was improved rapidly after distal leg perfusion. In the remaining case, the flow velocity was not decreased. In another one case, the stenosis at the cannulation site was detected after decannulation and repaired immediately. No limb ischemic complications were observed in this series.

CONCLUSION

Ultrasonographic assessment combined with the NIRS monitoring is useful to prevent lower limb ischemic complications after femoral arterial cannulation in MICS.

Femoral artery anatomy is a risk factor for limb ischemia in minimally invasive cardiac surgery

OBJECTIVE

In minimally invasive cardiac surgery (MICS), femoral artery cannulation during cardiopulmonary bypass (CPB) can cause limb ischemia. This study evaluated the association between femoral artery anatomy and the risk of limb ischemia in MICS.

METHODS

Eighty-one patients who underwent MICS with CPB using single femoral artery cannulation between 2010 and 2018 were included. The patients were stratified by their femoral artery diameter and anatomy of ectopic side branch, i.e., medial or lateral femoral circumflex arteries: Type A, deep femoral artery (DFA) ≥ superficial femoral artery (SFA); type B, DFA < SFA with an ectopic side branch of the common femoral artery (CFA); type C, DFA < SFA with an ectopic side branch at the CFA bifurcation; and type D, DFA < SFA without an ectopic side branch. The ratio of the postoperative creatine kinase concentration and the cross-sectional area of the femoral muscles (CK/MA) was used as a surrogate marker of limb ischemia. Predictors of high CK/MA were evaluated.

RESULTS

No critical limb ischemia was observed in this study. The median postoperative creatine kinase and CK/MA were 1954 (1305-2872) IU/l and 15.2 (9.2-19.8) IU/l/cm². Multivariable logistic regression found that anatomical type D (odds ratio 4.19, 95% confidence interval: (1.26-14.0); p = 0.020) and prolonged CPB time (OR 1.01, 95% CI (1.00-1.02); p = 0.045) were independent risk factors of high CK/MA.

CONCLUSION

Anatomical type D and prolonged CPB time were associated with risk of limb ischemia in MICS.

Use of Near-Infrared Spectroscopy to Monitor Lower Extremity Perfusion in Pediatric Patients Undergoing Cardiac Catheterization

Acute femoral artery occlusion is common in pediatric patients following cardiac catheterization. A variety of means are utilized to assess lower extremity (LE) perfusion and arterial patency following cardiac catheterization including palpation of pulses, pulse oximetry, subjective assessment of lower extremity color and temperature, and ultrasound. We sought to evaluate the utility of Near-Infrared Spectroscopy (NIRS) to monitor LE perfusion in pediatric patients undergoing cardiac catheterization. INVOS pediatric sensors were placed on bilateral LE in all pediatric patients ≤ 40 kg undergoing cardiac catheterization. Data were recorded continuously from the start of the procedure until 4-6 h after completion of the procedure. NIRS readings were compared between the accessed versus non-accessed LE at baseline before start of case, time of vascular access, arterial sheath exchange when applicable, sheath withdrawal, and Safeguard application, deflation, and removal. 133 patients underwent 152 catheterizations with mean age 2.4 ± 2.3 years and mean weight 12.4 ± 13.2 kg. NIRS oximetry readings were significantly decreased in the LE with arterial access compared to non-accessed LE from time of sheath insertion until removal of the pressure assist device post procedure. A greater difference was noted in smaller patients. NIRS oximetry readings did not correlate with subjective assessment of lower extremity perfusion after arterial sheaths were removed. One patient had pulse loss 4 h post procedure with a decrease in oximetry readings noted at this point on review. Weight-based heparin protocol was initiated, and a gradual improvement in oximetry readings was noted over the next 5 h. Vascular ultrasound 12 h later showed no evidence of arterial thrombus. NIRS may be helpful in identifying patients who are risk for developing arterial thrombus post cardiac catheterization and for monitoring response to therapy; however, further study in these patients is warranted.

Cerebral circulation estimated by laser speckle flowgraphy in retrograde femoral arterial perfusion during minimally invasive cardiac surgery

OBJECTIVES

Laser speckle flowgraphy (LSFG) is a novel modality to assess blood flow of the optic nerve head (ONH), which is reported to be a surrogate marker of cerebral microcirculation. We conducted LSFG measurements during minimally invasive cardiac surgery with retrograde femoral arterial perfusion and evaluated its feasibility and usability as a neuromonitor.

METHODS

We prospectively enrolled 7 patients who underwent mitral valve repair through a right minithoracotomy with retrograde femoral arterial perfusion. LSFG was used to analyse the ONH blood flow based on examinations of the mean blur rate (MBR). The MBR was measured after the induction of anaesthesia (time 1); after the initiation of cardiopulmonary bypass (time 2); during cardiac arrest (time 3) and after the termination of cardiopulmonary bypass (time 4).

RESULTS

All procedures were performed successfully, and there were no neurovascular complications or deaths. LSFG measurements were easily and uneventfully conducted without any related complications. The MBR was 11.2 ± 2.3 at time 1, 11.1 ± 1.8 at time 2, 11.3 ± 1.7 at time 3 and 13.6 ± 3.5 at time 4. Statistically, the MBR at time 4 was significantly higher than those at all other times ( P  < 0.05).

CONCLUSIONS

LSFG measurements were safely conducted during minimally invasive cardiac surgery and assessed ONH blood flow quantitatively. We consider this modality to be easy to manipulate and less operator dependent, resulting in good reproducibility. The results are well visualized and compared quantitatively. Our result suggests that LSFG might be an accurate neuromonitor.

Clinical trial registration

clinicaltrials.gov : 15102-2.

Minimally invasive mitral valve surgery through a right mini-thoracotomy

Since its introduction in the mid-1990s, minimally invasive mitral valve surgery (MIMVS) has been shown to be a feasible alternative to a conventional full-sternotomy approach, and several studies have reported excellent clinical outcomes with low perioperative morbidity and mortality. As a result, MIMVS is being increasingly employed as a routine procedure worldwide. On the other hand, several issues have been raised, including complications specific to this technique and its steep learning curve, while there are also concerns regarding the durability of a mitral valve repair through a limited access. In this study, the current status and future perspectives of MIMVS were examined.

The Peripheral Cannulation Technique in Minimally Invasive Congenital Cardiac Surgery

Congenital minimally invasive cardiac surgery has gained wide acceptance thanks to its favorable outcomes. The introduction of peripheral cannulation for cardiopulmonary bypass further reduces surgical trauma by decreasing surgical access and allowing the spectrum of surgical access for the correction of simple congenital heart defects to be widened. Right internal jugular vein percutaneous cannulation, together with the direct surgical cannulation of femoral vessels, proves to be a safe and effective tool in patients with body weight above 15 kg.

In vivo measurements of regional hemoglobin oxygen saturation values and limb-to-arm ratios of near-infrared spectroscopy for tissue oxygenation monitoring of lower extremities in healthy subjects

Objective

Near-infrared spectroscopy (NIRS) is a noninvasive technique that allows monitoring of regional hemoglobin oxygen saturation (rSO₂) values and might have a role in the diagnosis of peripheral arterial disease. We assessed the reproducibility and inter-subject variability of rSO₂ values and rSO₂ limb-to-arm ratios (LARs) in lower extremities of healthy subjects.

Methods

The rSO₂ values and rSO₂ LARs were calculated in eight healthy subjects without peripheral arterial disease. The rSO₂ values were measured at rest at six fixed spots at each lower limb and a reference spot at each upper arm. NIRS provided the rSO₂ values without involvement of any other processing technique. After measurements were completed, rSO₂ LARs were calculated by dividing the rSO₂ value of a lower extremity spot by the rSO₂ value of the arm. Measurements were performed twice on 1 day and repeated on 4 different days.

Results

Mean coefficients of variation of measurements of rSO₂ values and rSO₂ LARs at the same spot in the same subject were respectively less than 6% and 8% for every measurement spot over time. Coefficients of variation of measurements at the same spot between different subjects were less than 15% and 19% for every measurement spot respectively.

Conclusion

NIRS is an easily applicable, noninvasive tool for measurement of tissue oxygenation of lower extremities in healthy subjects. The reproducibility of rSO₂ values and rSO₂ LARs at the same measurement spot in the same subject is good.

Five hundred cases of robotic totally endoscopic coronary artery bypass grafting: predictors of success and safety

BACKGROUND

Robotic technology has enabled totally endoscopic coronary artery bypass (TECAB) grafting. Little information is available on factors associated with successful and safe performance of TECAB. We report a 10-year multicenter experience with 500 cases, elucidating on predictors of success and safety in TECAB procedures.

METHODS

Between 2001 and 2011, 500 patients (364 [73%] men; 136 [27%] women; median age [minimum-maximum] 60 years [31-90 years], median EuroSCORE 2 [0-13]), underwent TECAB. Single, double, triple, and quadruple TECAB was performed in 334, 150, 15, and 1 patient, respectively. Univariate analysis and binary regression models were used to identify predictors of success and safety. Success was defined as freedom from any adverse event and conversion procedure, safety was defined as freedom from major adverse cardiac and cerebral events, major vascular injury, and long-term ventilation.

RESULTS

Success and safety rates were 80% (400 cases) and 95% (474 cases), respectively. Intraoperative conversions to larger thoracic incisions were required in 49 (10%) patients. The median operative time was 305 minutes (112-1,050 minutes), and the mean lengths of stay in the intensive unit (ICU) and in hospital were 23 hours (11-1,048 hours) and 6 days (2-4 days), respectively. Independent predictors of success were single-vessel TECAB (p = 0.004), arrested-heart (AH)-TECAB (p = 0.027), non-learning curve case (p = 0.049), and transthoracic assistance (p = 0.035). The only independent predictor of safety was EuroSCORE (p = 0.002).

CONCLUSIONS

Single-vessel and multivessel TECAB procedures can be safely performed with good reproducible results. Predictors of success include procedure simplicity and non-learning curve cases, whereas predictors of safety are mainly associated with patient selection.

Predictors, causes, and consequences of conversions in robotically enhanced totally endoscopic coronary artery bypass graft surgery

BACKGROUND

Totally endoscopic coronary artery bypass graft surgery (TECAB), using the da Vinci telemanipulator, has become a reproducible operation at dedicated centers. As in every endoscopic operation, conversion is an important and probably inevitable issue.

METHODS

We performed robotic TECAB in 326 patients (age, 60 years; range, 31 to 90 years); 242 were single-vessel and 84 were multivessel TECAB.

RESULTS

Forty-six of 326 patients (14%) were converted to a larger incision (minithoracotomy, n = 5; sternotomy, n = 41). Left internal mammary artery injury (n = 7), epicardial injury (n = 4), balloon endoocclusion problems (n = 7), and anastomotic problems (n = 18) were common reasons for conversions. Conversion rate was significantly less for single-vessel versus multivessel TECABs (10% versus 25%; p = 0.001). Non-learning-curve case (7% versus 21%; p < 0.001) and transthoracic assistance (11% versus 22%; p = 0.018) were associated with lower conversion rates. In multivariate analysis, learning-curve case was the only independent predictor of conversion (p = 0.005). Conversion translated into increased packed red blood cell transfusion in the operating room (3 versus 0 units; p < 0.001), longer ventilation time (14 versus 8 hours; p < 0.001), and intensive care unit stay (45 versus 20 hours; p = 0.001). Hospital mortality was 0.6% in this series, with 1 patient in the conversion group (2.2%) and 1 patient in the nonconverted group (0.4%; not significant). Five-year survival was 98% in nonconverted patients and 88% in converted patients (p = 0.018). There was no difference in freedom from angina or freedom from major adverse cardiac and cerebral events.

CONCLUSIONS

Conversion in TECAB is primarily learning curve-dependent and associated with increased morbidity, but does not significantly affect hospital mortality. Both nonconverted and converted patients show good long-term survival, which is comparable to patients undergoing open sternotomy coronary artery bypass grafting. Long-term freedom from angina or freedom from major adverse cardiac and cerebral events is not influenced by conversion.