Anesthetic Management of Robotically Assisted Totally Endoscopic Coronary Artery Bypass Surgery (TECAB)

Does Intolerance of Single-Lung Ventilation Preclude Robotic Off-Pump Totally Endoscopic Coronary Bypass Surgery?

Objective

Robotic off-pump totally endoscopic coronary artery bypass (TECAB) usually requires isolated single (right) lung ventilation to adequately expose the surgical site. However, in some patients, persistent oxygen desaturation may occur and conversion to cardiopulmonary bypass (CPB) or sternotomy may be necessary. We reviewed the characteristics and clinical outcomes in patients who did not tolerate single-lung ventilation during TECAB surgery.

Methods

After Institutional Review Board approval we reviewed 440 patients undergoing robotic TECAB at our institution between July 2013 and April 2019. Patients were separated into 2 groups based on their ability to tolerate single-lung ventilation during the procedure. Group 1 included patients able to tolerate single-lung ventilation and Group 2 were patients who required double-lung ventilation to tolerate the procedure. Early and mid-term outcomes were compared.

Results

Group 2 (121 patients) had higher Society of Thoracic Surgeons scores, higher body mass index, and more triple-vessel disease than Group 1 (319 patients). Group 2 had more bilateral internal mammary artery use, multivessel grafting, and longer operative times. One patient underwent conversion to sternotomy and 5 required CPB (all in Group 1). Intensive care unit and hospital length of stay were longer in Group 2. Observed/expected mortality did not differ between groups (1.06% in Group 2 vs 0.4% in Group 1; P = 0.215). At mid-term follow-up, cardiac-related/overall mortality and freedom from major adverse cardiac events were similar.

Conclusions

In our cohort, intolerance of single-lung ventilation did not preclude robotic off-pump TECAB. Double-lung ventilation is feasible during the procedure and may prevent conversions to sternotomy or use of CPB, resulting in excellent early and mid-term outcomes.

Robotic Cardiac Surgery Part II: Anesthetic Considerations for Robotic Coronary Artery Bypass Grafting

Coronary artery bypass grafting represents one of the most commonly performed cardiac surgeries worldwide. Recently, interest has increased in providing patients with a less invasive approach to cardiac surgery, such as thoracotomy and endoscopic techniques using robotic technology as an alternative to traditional sternotomy. As the population gets older, the need for additional methods to provide care for sick patients will continue to expand. These advancements will further allow physicians to provide cardiac surgical procedures with less pain and faster recovery for patients.

Differential lung ventilation for increased oxygenation during one lung ventilation for video assisted lung surgery

BACKGROUND

One lung ventilation (OLV) is the technique used during lung resection surgery in order to facilitate optimal surgical conditions. OLV may result in hypoxemia due to the shunt created. Several techniques are used to overcome the hypoxemia, one of which is continuous positive airway pressure (CPAP) to the non-dependent lung. Another technique is ventilating the non-dependent lung with a minimal volume, thus creating differential lung ventilation (DLV). In this study we compared the efficacy of CPAP to DLV during video assisted thoracoscopic lung resection.

PATIENTS AND METHOD

This is a prospective study of 30 adult patients undergoing elective video assisted thoracoscopic lung lobectomy. Each patient was ventilated in four modes: two lung ventilation, OLV, OLV + CPAP and OLV + DLV. Fifteen patients were ventilated with CPAP first and DLV next, and the other 15 were ventilated with DLV first and then CPAP. Five minutes separated each mode, during which the non-dependent lung was open to room air. We measured the patient's arterial blood gas during each mode of ventilation. The surgeons, who were blinded to the ventilation technique, were asked to assess the surgical conditions at each stage.

RESULTS

Oxygenation during OLV+ CPAP was significantly lower that OLV + DLV (p = 0.018). There were insignificant alterations of pH, PCO2 and HCO3 during the different ventilating modes. The surgeons' assessments of interference in the field exposure between OLV + CPAP or OLV + DLV was found to be insignificant (p = 0.073).

CONCLUSIONS

During OLV, DLV is superior to CPAP in improving patient's oxygenation, and may be used where CPAP failed.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03563612 . Registered 9 June 2018, retrospectively (due to clerical error).

Anaesthetic issues in robotic-assisted minimally invasive surgery

Over the past decade there has been an exponential increase in the number of robotic-assisted surgical procedures performed in Australia and internationally. Despite this growth, there are no level I or II studies examining the anaesthetic implications of these procedures. Available observational studies provide insight into the significant challenges for the anaesthetist. Most anaesthetic considerations overlap with those of non-robotic surgery. However, issues with limited patient access and extremes of positioning resulting in physiological disturbances and risk of injury are consistently demonstrated concerns specific to robotic-assisted procedures.

Anesthetic issues for robotic cardiac surgery

As innovative technology continues to be developed and is implemented into the realm of cardiac surgery, surgical teams, cardiothoracic anesthesiologists, and health centers are constantly looking for methods to improve patient outcomes and satisfaction. One of the more recent developments in cardiac surgical practice is minimally invasive robotic surgery. Its use has been documented in numerous publications, and its use has proliferated significantly over the past 15 years. The anesthesiology team must continue to develop and perfect special techniques to manage these patients perioperatively including lung isolation techniques and transesophageal echocardiography (TEE). This review article of recent scientific data and personal experience serves to explain some of the challenges, which the anesthetic team must manage, including patient and procedural factors, complications from one-lung ventilation (OLV) including hypoxia and hypercapnia, capnothorax, percutaneous cannulation for cardiopulmonary bypass, TEE guidance, as well as methods of intraoperative monitoring and analgesia. As existing minimally invasive techniques are perfected, and newer innovations are demonstrated, it is imperative that the cardiothoracic anesthesiologist must improve and maintain skills to guide these patients safely through the robotic procedure.

Real-time ventilation and perfusion distributions by electrical impedance tomography during one-lung ventilation with capnothorax

BACKGROUND

Carbon dioxide insufflation into the pleural cavity, capnothorax, with one-lung ventilation (OLV) may entail respiratory and hemodynamic impairments. We investigated the online physiological effects of OLV/capnothorax by electrical impedance tomography (EIT) in a porcine model mimicking the clinical setting.

METHODS

Five anesthetized, muscle-relaxed piglets were subjected to first right and then left capnothorax with an intra-pleural pressure of 19 cm H2 O. The contra-lateral lung was mechanically ventilated with a double-lumen tube at positive end-expiratory pressure 5 and subsequently 10 cm H2 O. Regional lung perfusion and ventilation were assessed by EIT. Hemodynamics, cerebral tissue oxygenation and lung gas exchange were also measured.

RESULTS

During right-sided capnothorax, mixed venous oxygen saturation (P = 0.018), as well as a tissue oxygenation index (P = 0.038) decreased. There was also an increase in central venous pressure (P = 0.006), and a decrease in mean arterial pressure (P = 0.045) and cardiac output (P = 0.017). During the left-sided capnothorax, the hemodynamic impairment was less than during the right side. EIT revealed that during the first period of OLV/capnothorax, no or very minor ventilation on the right side could be seen (3 ± 3% vs. 97 ± 3%, right vs. left, P = 0.007), perfusion decreased in the non-ventilated and increased in the ventilated lung (18 ± 2% vs. 82 ± 2%, right vs. left, P = 0.03). During the second OLV/capnothorax period, a similar distribution of perfusion was seen in the animals with successful separation (84 ± 4% vs. 16 ± 4%, right vs. left).

CONCLUSION

EIT detected in real-time dynamic changes in pulmonary ventilation and perfusion distributions. OLV to the left lung with right-sided capnothorax caused a decrease in cardiac output, arterial oxygenation and mixed venous saturation.

The year in cardiothoracic and vascular anesthesia: selected highlights from 2013

This article reviewed selected research highlights of 2013 that pertain to the specialty of cardiothoracic and vascular anesthesia. The first major theme is the commemoration of the sixtieth anniversary of the first successful cardiac surgical procedure with cardiopulmonary bypass conducted by Dr Gibbon. This major milestone revolutionized the practice of cardiovascular surgery and invigorated a paradigm of mechanical platforms for contemporary perioperative cardiovascular practice. Dr Kolff was also a leading contributor in this area because of his important contributions to the refinement of cardiopulmonary bypass and mechanical ventricular assistance. The second major theme is the diffusion of echocardiography throughout perioperative practice. There are now guidelines and training pathways to guide its generalization into everyday practice. The third major theme is the paradigm shift in perioperative fluid management. Recent large randomized trials suggest that fluids are drugs that require a precise prescription with respect to type, dose, and duration. The final theme is patient safety in the cardiac perioperative environment. A recent expert scientific statement has focused attention on this issue because most perioperative errors are preventable. It is likely that clinical research in this area will blossom because this is a major opportunity for improvement in our specialty. The patient care processes identified in these research highlights will further improve perioperative outcomes for our patients.