Intraoperative esophageal Doppler hemodynamic monitoring in free perforator flap surgery

Dobutamine and Goal-Directed Fluid Therapy for Improving Tissue Oxygenation in Deep Inferior Epigastric Perforator (DIEP) Flap Breast Reconstruction Surgery: Protocol for a Randomized Controlled Trial

BACKGROUND

Breast reconstruction is an integral part of breast cancer care. There are 2 main types of breast reconstruction: alloplastic (using implants) and autologous (using the patient's own tissue). The latter creates a more natural breast mound and avoids the long-term need for surgical revision-more often associated with implant-based surgery. The deep inferior epigastric perforator (DIEP) flap is considered the gold standard approach in autologous breast reconstruction. However, complications do occur with DIEP flap surgery and can stem from poor flap tissue perfusion/oxygenation. Hence, the development of strategies to enhance flap perfusion (eg, goal-directed perioperative fluid therapy) is essential. Current perioperative fluid therapy is traditionally guided by subjective criteria, which leads to wide variations in clinical practice.

OBJECTIVE

The main objective of this trial is to determine whether the use of minimally invasive cardiac output (CO) monitoring for guiding intravenous fluid administration, combined with low-dose dobutamine infusion (via a treatment algorithm), will increase tissue oxygenation in patients undergoing DIEP flap surgery.

METHODS

With appropriate institutional ethics board and Health Canada approval, patients undergoing DIEP flap surgery are randomly assigned to receive CO monitoring for the guidance of intraoperative fluid therapy in addition to a low-dose dobutamine infusion (which potentially improves flap oxygenation) versus the current standard of care. The primary outcome is tissue oxygenation measured via near-infrared spectroscopy at the perfusion zone furthest from the perforator vessels 45 minutes after vascular reanastomosis of the DIEP flap. Low dose (2.5 μg/kg/hr) dobutamine infusion continues for up to 4 hours postoperatively, provided there are no associated complications (ie, persistent tachycardia). Flap oxygenation, hemodynamic parameters, and any medication-associated side effects/complications are monitored for up to 48 hours postoperatively. Complications, rehospitalizations, and patient satisfaction are also collected until 30 days postoperatively.

RESULTS

Funding and regulatory approvals were obtained in 2019, but the study recruitment was interrupted by the COVID-19 pandemic. As of October 4, 2023, 34 participants have been recruited. Because of the significant delays associated with the pandemic, the expected completion date was extended. We expect the study to be completed and ready for potential news release (as appropriate) and publication by July 2024. No patients have suffered any adverse effects/complications from participating in this study, and none have been lost to follow-up.

CONCLUSIONS

CO-directed fluid therapy in combination with a low-dose dobutamine infusion via a treatment algorithm has the potential to improve DIEP flap tissue oxygenation and reduce complications following DIEP flap breast reconstruction surgery. However, given that the investigators remain blinded to group randomization, no comment can be made regarding the efficacy of this intervention for improving tissue oxygenation at this time. Nevertheless, no patients have been withdrawn for safety concerns thus far, and compliance remains high.

TRIAL REGISTRATION

Clinicaltrials.gov NCT04020172; https://clinicaltrials.gov/study/NCT04020172.

Enhanced Recovery after Surgery Protocols Decrease Outpatient Opioid Use in Patients Undergoing Abdominally Based Microsurgical Breast Reconstruction

BACKGROUND

Enhanced recovery after surgery (ERAS) protocols have known benefits in the inpatient setting, but little is known about their impact in the subsequent outpatient setting. On discharge, multimodal analgesia has been discontinued, nerve blocks and pain pumps have worn off, and patients enter a substantially different physical environment, potentially resulting in a rebound effect. The objective of this study was to investigate the effect of ERAS protocol implementation on outpatient opioid use and recovery.

METHODS

Patients who underwent abdominally based microsurgical breast reconstruction before and after ERAS implementation were reviewed retrospectively. Ohio state law mandates that no more than 7 days of opioids may be prescribed at a time, with the details of all prescriptions recorded in a statewide reporting system, from which opioid use was determined.

RESULTS

A total of 105 patients met inclusion criteria, of which 46 (44 percent) were in the pre-ERAS group and 59 (56 percent) were in the ERAS group. Total outpatient morphine milligram equivalents used in the ERAS group were less than in the pre-ERAS group (337.5 morphine milligram equivalents versus 668.8 morphine milligram equivalents, respectively; p =0.016). This difference was specifically significant at postoperative week 1 (p =0.044), with gradual convergence over subsequent weeks. Although opioid use was significantly less in the ERAS group, pain scores in the ERAS group were comparable to those in the pre-ERAS group.

CONCLUSIONS

The benefits of ERAS protocols appear to extend into the outpatient setting, further supporting their use to facilitate recovery, and highlighting their potential role in helping to address the prescription opioid abuse problem.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

100 Steps of a DIEP Flap-A Prospective Comparative Cohort Series Demonstrating the Successful Implementation of Process Mapping in Microsurgery

Background

The demand to improve the efficiency of microsurgical breast reconstruction is driven by increasing number of breast cancer and risk reducing cases, and the concurrent requirement for hospitals to cut costs. Businesses have successfully used process mapping as a tool to improve efficiency; however, process mapping has been sparsely used in surgery. This prospective cohort study has used process mapping to break down the individual components of a deep inferior epigastric artery perforator (DIEP) flap operation into a template of 100 streamlined steps.

Methods

Through observation of the senior author's uniform technique, refined from experience of over 5,000 cases, the DIEP flap operation was broken down into 100 individual steps, all arranged in a logical sequence with which to maximize efficiency and outcome. This created a 100-step process-mapped template. Subsequently, 2 cohorts of 10 unilateral DIEP cases were prospectively timed. One cohort following this process mapped template and the other control group was blinded to the template.

Results

The process-mapped cohort was 56.1 minutes quicker than the control cohort, despite the addition of symmetrizing surgery being performed concurrently in 4 out of the 10 cases. Furthermore, there was no return to theater in the process-mapped cohort versus 1 return to theater in the control cohort with no flap loss in either group.

Conclusions

This study uniquely presents an approach to process map the DIEP flap operation and demonstrates its utility in improving operative efficiency, without compromising outcomes. It also illustrates the possibility of symmetrizing surgery being carried out through parallel operating processes, without affecting overall operative times.

Perioperative goal-directed therapy: A systematic review without meta-analysis

BACKGROUND

Perioperative goal-directed therapy aims to optimise haemodynamics by titrating fluids, vasopressors and/or inotropes to predefined haemodynamic targets. Perioperative goal-directed therapy is a complex intervention composed of several independent component interventions. Trials on perioperative goal-directed therapy show conflicting results. We aimed to conduct a systematic review and meta-analysis to investigate the benefits and harms of perioperative goal-directed therapy.

METHODS

PubMED, EMBASE, Web of Science and Cochrane Library were searched. Trials were included if they had a perioperative goal-directed therapy protocol. The primary outcome was all-cause mortality. The first secondary outcome was serious adverse events excluding mortality. Risk of bias was assessed, and GRADE was used to evaluate quality of evidence.

RESULTS

One hundred and twelve randomised trials were included of which one trial (1%) had low risk of bias. Included trials varied in patients: types of surgery which was expected due to inclusion criteria; in intervention and comparison: timing of intervention, monitoring devices, haemodynamic variables, target values, use of fluids, vasopressors and/or inotropes as well as combinations of these within protocols; and in outcome: mortality was reported in 87 trials (78%). Due to substantial clinical heterogeneity also within the various types of surgery a meta-analysis of data, including subgroup analyses, as defined in our protocol was considered inappropriate.

CONCLUSION

Clinical heterogeneity in patients, interventions and outcomes in perioperative goal-directed therapy trials is too large to perform meta-analysis on all trials. Future trials and meta-analyses highly depend on universally agreed definitions on aspects beyond type of surgery of the complex intervention and its evaluation.

Three routine free flaps per day in a single operating theatre: principles of a process mapping approach to improving surgical efficiency

BACKGROUND

Breast reconstruction is a multi-stage process, involving many individual procedures and many healthcare professionals which take the patient through from diagnosis of breast cancer to the completion of cancer treatment and ultimate breast reconstruction. With an experience of over 3,000 autologous breast reconstructions, we have refined both our surgical technique and overall approach to breast reconstruction to improve the efficiency in free flap based breast reconstruction surgery.

METHODS

Through a process mapping approach similar to that employed by large-scale industry, we have broken down free flap based breast reconstruction into multiple smaller processes. By looking at various steps as a simple component of the whole, we have improved our theatre efficiency to maximize patient throughput and improve our outcomes for breast reconstruction patients.

RESULTS

Since beginning free flap breast reconstruction surgery, we have improved overall efficiency by applying a process mapping approach. In our early experience, we undertook a single patient undergoing breast reconstruction with a free flap per theatre list, moving to two patients having breast reconstruction, and now carry out three free flap based reconstructions in a single theatre per day as a routine. Specific times are demonstrated, with no increased complication rate.

CONCLUSIONS

Through clearly defined processes, operative efficiency in autologous breast reconstruction can achieve three free flaps per day in a single theatre.

A review of intraoperative goal-directed therapy using arterial waveform analysis for assessment of cardiac output

Increasing evidence shows that goal-directed hemodynamic management can improve outcomes in surgical and intensive care settings. Arterial waveform analysis is one of the different techniques used for guiding goal-directed therapy. Multiple proprietary systems have developed algorithms for obtaining cardiac output from an arterial waveform, including the FloTrac, LiDCO, and PiCCO systems. These systems vary in terms of how they analyze the arterial pressure waveform as well as their requirements for invasive line placement and calibration. Although small-scale clinical trials using these monitors show promising data, large-scale multicenter trials are still needed to better determine how intraoperative goal-directed therapy with arterial waveform analysis can improve patient outcomes. This review provides a comparative analysis of the different arterial waveform monitors for intraoperative goal-directed therapy.

Perioperative anaesthetic practice for head and neck free tissue transfer -- a UK national survey

BACKGROUND

Anaesthetic management of microvascular head and neck free flap surgery is based on physiological principles, but data on how these affect clinical outcomes in this challenging group are limited. There are no evidence-based guidelines available in this area.

METHODS

To establish current perioperative anaesthetic practice by surveying all UK centres performing head and neck free flap surgery. Anaesthetists from 73 centres performing head and neck microvascular reconstructive surgery in the UK were asked to complete a structured online survey. The survey included general questions, a hypothetical clinical scenario with multiple choice questions and questions about perioperative management. The main outcomes measured were protocols of pre-operative assessment, perioperative fluid and blood pressure strategies, monitoring and post-operative management.

RESULTS

Seventy-three units were contacted, and fifty-five responded (75%). Most respondents performed up to two cases per month. Opinion was divided as to how best to manage intra-operative blood pressure, fluid balance, pre-operative assessment and monitoring. Notably 52% preferred crystalloid infusion to increase blood pressure, while 35% stated crystalloids were contraindicated.

CONCLUSIONS

Currently in the UK, anaesthetic perioperative management for head and neck free flap transfer is varied, reflecting the paucity of high-quality data in this area; but some techniques, in particular avoidance of excessive crystalloid use, is associated with improved flap outcome.