Intraoperative vasopressors and thrombotic complications in free flap breast reconstruction

The Influence of Vasopressors on Free Flap Outcomes in Head and Neck Cancer Patients

OBJECTIVE

To compare free flap outcomes between those who received and did not receive vasopressors (VPs) at the time of free flap reconstruction.

STUDY DESIGN

This retrospective cohort study includes patients from January 2013 to January 2023.

SETTING

This multicenter cohort study utilized data from the TriNetX Research Network which includes 80 health care organizations.

METHODS

Head and neck cancer patients older than 18 years who underwent free flap reconstruction were separated into those who received or did not receive VPs on the day of surgery. The primary outcomes were flap failure defined by need for secondary free flap procedures, blood vessel repair, and other flap revision procedures.

RESULTS

After propensity score matching, 7446 patients were analyzed. The VP group included 3723 patients (mean age [SD], 62.9 [11.4] years; 2511 males [67.4%]). The non-VP group included 3723 patients (mean age [SD], 63.0 [11.2] years; 2479 males [66.6%]). Free flap outcomes were not statistically different between groups (secondary free flap: 166 [4.5%] VP vs 155 [4.2%] non-VP, P = .04; vessel repair: 314 [8.4%] vs 319 [8.6%], P = .06; other flap revision procedures: 416 [11.2%] vs 449 [12.1%], P = .02). Bony flaps were found to have decreased rates of vessel repair in the VP group (47 [6.1%] vs 69 [9.0%], P = .003]. For secondary outcomes, pneumonia (173 [4.6%] vs 231 [6.2%], P = .0002), urinary tract infection (34 [1.0%] vs 59 [1.6%], P = .0007), and deep vein thrombosis (93 [2.5%] vs 122 [3.3%], P = .004) were significantly different.

CONCLUSION

VP use is not significantly associated with free flap complications. These results imply that VP use on the same day as surgery may be safe if clinically necessary.

Perioperative hypotension and use of vasoactive agents in non-cardiac surgery: A scoping review

BACKGROUND

Perioperative hypotension is common and associated with adverse patient outcomes. Vasoactive agents are often used to manage hypotension, but the ideal drug, dose and duration of treatment has not been established. With this scoping review, we aim to provide an overview of the current body of evidence regarding the vasoactive agents used to treat perioperative hypotension in non-cardiac surgery.

METHODS

We included all studies describing the use of vasoactive agents for the treatment of perioperative hypotension in non-cardiac surgery. We excluded literature reviews, case studies, and studies on animals and healthy subjects. We posed the following research questions: (1) in which surgical populations have vasoactive agents been studied? (2) which agents have been studied? (3) what doses have been assessed? (4) what is the duration of treatment? and (5) which desirable and undesirable outcomes have been assessed?

RESULTS

We included 124 studies representing 10 surgical specialties. Eighteen different agents were evaluated, predominantly phenylephrine, ephedrine, and noradrenaline. The agents were administered through six different routes, and numerous comparisons between agents, dosages and routes were included. Then, 88 distinct outcome measures were assessed, of which 54 were judged to be non-patient-centred.

CONCLUSIONS

We found that studies concerning vasoactive agents for the treatment of perioperative hypotension varied considerably in all aspects. Populations were heterogeneous, interventions and exposures included multiple agents compared against themselves, each other, fluids or placebo, and studies reported primarily non-patient-centred outcomes.

Intraoperative vasopressor use does not increase complications in microvascular post-mastectomy breast reconstruction: Experience in 1729 DIEP flaps at a single center

INTRODUCTION

Vasopressors are traditionally avoided in microsurgery due to concerns about their effect on free flap survival. We examine the impact of intraoperative vasopressors on microsurgical outcomes in a large series of DIEP flap breast reconstructions.

METHODS

A retrospective chart review was performed of patients who underwent DIEP breast reconstruction between January 2010 and May 2020. Intraoperative and postoperative microsurgical outcomes were compared in patients who received vasopressors and those who did not.

RESULTS

The study included 1102 women who underwent 1729 DIEP. 878 patients (79.7%) received intraoperative phenylephrine, ephedrine, or a combination of both. There was no significant difference in overall complications, intraoperative microvascular events, takebacks for microvascular complications, or partial or total flap loss between groups. Outcomes were not affected by vasopressor type, dose, or timing of administration. The vasopressor group received significantly lower intraoperative fluid volumes. Multivariate logistic regression found a significant association between overall complications and excessive fluids (OR 2.03, 99% CI 0.98-5.18, p = 0.03) but not vasopressor use (OR 0.79, 99% CI 0.64-3.16, p = 0.7) CONCLUSION: This study demonstrates that vasopressors do not adversely affect clinical outcomes after DIEP breast reconstruction. Withholding vasopressors results in excessive intravenous fluid administration and increased postoperative complications.

Norepinephrine preserved flap blood flow compared to phenylephrine in free transverse rectus abdominis myocutaneous flap breast reconstruction surgery: A randomized pilot study

BACKGROUND

Vasopressors are used in up to 85% of cases during free flap surgery. However, their use is still debated with concerns of vasoconstriction-related complications, with rates up to 53% in minor cases. We investigated the effects of vasopressors on flap blood flow during free flap breast reconstruction surgery. We hypothesized that norepinephrine may preserve flap perfusion better than phenylephrine during free flap transfer.

METHODS

A randomized pilot study was performed in patients undergoing free transverse rectus abdominis myocutaneous (TRAM) flap breast reconstruction. Patients with peripheral artery disease, allergies to study drugs, previous abdominal operations, left ventricular dysfunction, or uncontrolled arrhythmias were excluded. Twenty patients were randomized to receive either norepinephrine (0.03-0.10 µg/kg/min) or phenylephrine (0.42-1.25 µg/kg/min) (each n = 10) to maintain a mean arterial pressure of 65-80 mmHg. The primary outcome was differences in mean blood flow (MBF) and pulsatility index (PI) of flap vessels after anastomosis measured using transit time flowmetry in the two groups. Secondary outcomes included flap loss, necrosis, thrombosis, wound infection, and reoperation within 7 days postoperatively.

RESULTS

After anastomosis, MBF showed no significant change in the norepinephrine group (mean difference, -9.4 ± 14.2 mL/min; p = 0.082), whereas it was reduced in the phenylephrine group (-7.9 ± 8.2 mL/min; p = 0.021). PI did not change in either group (0.4 ± 1.0 and 1.3 ± 3.1 in the norepinephrine and phenylephrine groups; p = 0.285 and 0.252, respectively). There were no differences in secondary outcomes between the groups.

CONCLUSION

During free TRAM flap breast reconstruction, norepinephrine seems to preserve flap perfusion compared to phenylephrine. However, further validation studies are required.

Evidence based recommendations for perioperative vasopressor use and fluid resuscitation in microsurgery

Blood pressure regulation is critical in patients undergoing microsurgical free tissue transfer; however, guidelines for addressing and preventing perioperative hypotension remain highly debated, with two current thought paradigms: (1) intravenous fluid administration with a balanced salt solution (e.g., lactate ringer and normal saline) and/or colloid (e.g., albumin) and (2) vasoactive pharmacological support with vasopressors (e.g., dobutamine, norepinephrine, epinephrine), with fluid administration being the preferred conventional approach. Here, we review the most up to date available literature and summarize currents perspectives and practices for fluid resuscitation and vasopressor use, while offering evidence-based guidelines to each.

Characterizing Intraoperative Vasopressor Use in Total Knee Arthroplasty: A Retrospective Cohort Study

Preoperative optimization and protocols for joint replacement care pathways have led to decreased length of stay (LOS)and narcotic use, and are increasingly important in delivering quality, cost savings, and shifting appropriate cases to an outpatient setting. The intraoperative use of vasopressors is independently associated with increased LOS and risk of adverse postoperative events including death, and in total hip arthroplasty, there is an increased risk for intensive care unit (ICU) admission. Our aim is to characterize the patient characteristics associated with vasopressor use specifically in total knee arthroplasty (TKA). We retrospectively reviewed the electronic medical records of a cohort of patients who underwent inpatient primary TKA at a single academic hospital from January 1, 2017 to December 31, 2018. Demographics, comorbidities, perioperative factors, and intraoperative medication administration were compared with multivariate regression to identify patients who may require intraoperative vasopressors. Out of these, 748 patients underwent TKA, 439 patients required intraoperative vasopressors, while 307 did not. Significant independent predictors of vasopressor use were older age (odds ratio [OR] = 1.06, 95% confidence interval [CI]: 1.03-1.08) and history of a prior cerebrovascular accident (CVA; OR = 11.80, CI: 1.48-93.81). While not significant, male sex (OR = 0.72, CI: 0.50-1.04) and regional anesthesia (OR = 0.64, CI: 0.40-1.05) were nearing significance as negative independent predictors of vasopressor use. In a secondary analysis, we did not observe an increase in complications attributable to vasopressor administration intraoperatively. In conclusion, nearly 59% of patients undergoing TKA received intraoperative vasopressor support. History of stroke and older age were significantly associated with increased intraoperative vasopressor use. As the first study to examine vasopressor usage in a TKA patient population, we believe that understanding the association between patient characteristics and intraoperative vasopressor support will help orthopaedic surgeons select the appropriate surgical setting during preoperative optimization.

Hyponatremia after Autologous Breast Reconstruction: A Cohort Study Comparing Two Fluid Management Protocols

BACKGROUND

 Perioperative fluid management is an important component of enhanced recovery pathways for microsurgical breast reconstruction. Historically, fluid management has been liberal. Little attention has been paid to the biochemical effects of different protocols. This study aims to reduce the risk of postoperative hyponatremia by introducing a new fluid management protocol.

METHODS

 A single-institution cohort study comparing a prospective series of patients was managed using a new "modestly restrictive" fluid postoperative fluid management protocol to a control group managed with a "liberal" fluid management protocol.

RESULTS

 One-hundred thirty patients undergoing microsurgical breast reconstruction, at a single institution during 2021, are reported. Hyponatremia is demonstrated to be a significant risk with the original liberal fluid management protocol. At the end of the first postoperative day, mean fluid balance was +2,838 mL (± 1,630 mL). Twenty-four patients of sixty-five (36%) patients had low blood sodium level, 14% classified as moderate-to-severe hyponatremia. Introducing a new, "modestly-restrictive" protocol reduced mean fluid balance on day 1 to +844 mL (±700) (p ≤ 0.0001). Incidence of hyponatremia reduced from 36 to 14% (p = 0.0005). No episodes of moderate or severe hyponatremia were detected. Fluid intake, predominantly oral water, between 8am and 8pm on the first postoperative day is identified as the main risk factor for developing hyponatremia (odds ratio [OR]: 7; p = 0.019). Modest fluid restriction, as guided by the new protocol, protects patients from low sodium level (OR: 0.25; confidence interval: 95%; 0.11-1.61; p = 0.0014).

CONCLUSION

 The original "liberal" fluid management protocol encouraged unrestricted postoperative oral intake of water. Patients were often advised to consume in excess of 5 L in the first 24 hours. This unintentionally, but frequently, was associated with moderate-to-severe hyponatremia. We present a new protocol characterized by early cessation of intravenous fluid and an oral fluid limit of 2,100 mL/day associated with a significant reduction in the incidence of hyponatremia and fluid overload.

Intraoperative Vasopressor Usage in Free Tissue Transfer: Should We Be Worried?

BACKGROUND

 The role of vasopressors has long been a subject of debate in microsurgery. Conventional wisdom dictates the avoidance of vasopressor use, due to concerns such as peripheral vasoconstriction, inducing vasospasm of the anastomoses, and leading to failure in perfusion. It has since become common practice in some centers to avoid intraoperative vasopressor use during free tissue transfer surgery. Recent studies have suggested that this traditional view may not be supported by clinical evidence. However, none of these studies have separated vasopressor use by method of administration.

METHODS

 We conducted a retrospective review of our experience of vasopressor use in free flap surgery at a single high-volume center. The outcome measures were flap failure, flap-related complications and overall postoperative complications (reported using the Clavien-Dindo classification). Groups were compared using Chi-square or Fisher's Exact test where appropriate.

RESULTS

 A total of 777 cases in 717 patients were identified. 59.1% of these had vasopressors administered intraoperatively. The overall failure rate was 2.2%, with 9.8% experienced flap-related complications. There was no difference in flap loss when vasopressors were administered, but an increased rate of microvascular thrombosis was noted (p = 0.003). Continuous administration of vasopressors was associated with reduced venous congestion, whereas intermittent boluses increased risk of microvascular thrombosis.

CONCLUSION

 Our study confirms previous findings that intraoperative vasopressor use in free flap surgery is not associated with increased failure rate. Administering vasopressors continuously may be safer than via repeated boluses.

Oncoplastic breast surgery: A guide to good practice

Oncoplastic Breast Surgery has become standard of care in the management of Breast Cancer patients. These guidelines written by an Expert Advisory Group; convened by the Association of Breast Surgery (ABS) and the British Association of Plastic, Reconstructive and Aesthetic Surgeons (BAPRAS), are designed to provide all members of the breast cancer multidisciplinary team (MDT) with guidance on the best breast surgical oncoplastic and reconstructive practice at each stage of a patient's journey, based on current evidence. It is hoped they will also be of benefit to the wide range of professionals and service commissioners who are involved in this area of clinical practice.

Goal-directed fluid therapy in autologous breast reconstruction results in less fluid and more vasopressor administration without outcome compromise

OBJECTIVE

Aggressive or restricted perioperative fluid management has been shown to increase complications in patients undergoing microsurgery. Goal-directed fluid therapy (GDFT) aims to administer fluid, vasoactive agents, and inotropes according to each patient's hemodynamic indices. This study assesses GDFT impact on perioperative outcomes of autologous breast reconstruction (ABR) patients, as there remains a gap in management understanding. We hypothesize that GDFT will have lower fluid administration and equivocal outcomes compared to patients not on GDFT.

METHODS

A single-center retrospective review was conducted on ABR patients from January 2010-April 2017. An enhanced recovery after surgery (ERAS) using GDFT was implemented in April 2015. With GDFT, patients were administered intraoperative fluids and vasoactive agents according to hemodynamic indices. Patients prior to April 2015 were included in the pre-ERAS cohort. Primary outcomes included the amount and rate of fluid delivery, urine output (UOP), vasopressor administration, major (i.e., flap failure) and minor (i.e., seroma) complications, and length of stay (LOS).

RESULTS

Overall, 777 patients underwent ABR (ERAS: 312 and pre-ERAS: 465). ERAS patients received significantly less total fluid volume (ERAS median: 3750 mL [IQR: 3000-4500 mL]; pre-ERAS median: 5000 mL [IQR 4000-6400 mL]; and p<0.001), had lower UOP, were more likely to receive vasopressor agents (47% vs 35% and p<0.001), and had lower LOS (ERAS: 4 days [4-5]; pre-ERAS: 5 [4-6]; and p<0.001) as compared to pre-ERAS patients. Complications did not differ between cohorts.

CONCLUSIONS

GDFT, as part of ERAS, and the prudent use of vasopressors were found to be safe and did not increase morbidity in ABR patients. GDFT provides individualized perioperative care to the ABR patient.

Intraoperative vasopressors in head and neck free flap reconstruction

INTRODUCTION

Historically, there were concerns vasopressors impair free flap outcomes, but recent studies suggest vasopressors are safe. Here we investigate this controversy by (1) evaluating vasopressors' effect on head and neck free-flap survival and surgical complications, and (2) performing soft tissue and bony subset analysis.

PATIENTS AND METHODS

Post hoc analysis was performed of a single-blinded, prospective, randomized clinical trial at a tertiary care academic medical center involving patients ≥18 years old undergoing head and neck free flap reconstruction over a 16-month period. Patients were excluded if factors prevented accurate FloTrac™ use. Patients were randomized to traditional volume-based support, or goal-directed support including vasopressor use. Primary data was obtained by study personnel through intraoperative data recording and postoperative medical record review.

RESULTS

Forty-one and 38 patients were randomized to traditional and pressor-based algorithms, respectively. Flap survival was 95% (75/79). There was no significant difference between the pressor-based and traditional protocols' flap failure (1/38 [3%] vs. 3/41 [7%], RR 0.36, 95% CI of RR 0.04-3.31, p = .63) or flap-related complications (12/38 [32%] vs. 18/41 [44%], RR 0.72, 95% CI 0.40-1.29, p = .36) Soft tissue flaps had surgical complication rates of 12/30 (40%) and 9/27 (33%) for traditional and pressor-based protocols, respectively. Bony flaps had surgical complication rates of 6/11 (55%), and 3/11 (27%) for traditional and pressor-based protocols, respectively.

CONCLUSIONS

Intraoperative goal-directed vasopressor administration during head and neck free flap reconstruction does not appear to increase the rate of flap complications or failures.

Identifying perioperative volume-related risk factors in head and neck surgeries with free flap reconstructions - An investigation with focus on the influence of red blood cell concentrates and noradrenaline use

INTRODUCTION

The amount of fluids administered intraoperatively seems to influence the postoperative outcome, and especially the transfusion of red blood cell concentrates (RBC) are known to have an increased risk of postoperative complications. This prospective study focuses on patients planned with microvascular free flap reconstruction and investigates the effect of various types and amounts of volumes given intraoperatively and on the intensive care unit with regard to overall postoperative complications.

MATERIAL AND METHODS

In this prospective study, 52 consecutive patients planned for reconstruction with microvascular free flaps were included. Intraoperatively administered volumes including blood products were documented by the anesthesiologists as well as volumes given during the intensive care unit stay. Postoperative complications were registered for the entire hospital stay. Statistical analysis was carried out correlating the amount and type of volumes with the incidence of postoperative complications.

RESULTS

The intraoperative use of RBC showed a close to statistically significant increased risk of postoperative complications (mean/SD concentrates: 0.5/1.1 [no complications] vs. 1.0/1.4 [complications], p = 0.058). In a multivariate analysis with stepwise selection the use of human albumin, gelatin, or Ringer's acetate showed no correlation with complications. The overall blood loss, however, had no significant influence on the incidence of complications (mean/SD ml: 1187/761 [no complications] vs. 1004/600 [complications], p = 0.37). The use of noradrenalin during reconstructive surgeries with microvascular flaps bears statistically no increased risk of failure (mean/SD μg/kg/min: 36/23 [no flap loss] vs. 22/15 [flap loss], p = 0.289) or complications (mean/SD μg/kg/min: 34/22 [no complications] vs. 35/23 [complications], p = 0.807).

CONCLUSION

In our investigation, the use of crystalloids and colloids seems to have no influence on the postoperative outcome, but the use of RBC may have an increased overall incidence of postoperative complications. A careful hemostasis to limit the use of RBC remains essential despite available options of substitutions. The use of infusion-pump-administered noradrenaline seems valuable to sustain a stable circulation during surgeries with microvascular free flaps and may have no negative impact on postoperative complications.

Effects of vasopressors on circulation in the porcine abdominal island flap model

BACKGROUND

During reconstructive surgical procedures, systemic vasopressors are frequently used to maintain normal blood pressure. However, questions have arisen regarding the pharmacologic effects of vasopressors on flap circulation. Many plastic surgeons have expressed concern about the possibility of impaired flap circulation caused by the vasoconstrictive effect of the drugs. However, the opposing argument exists that the increase in mean arterial pressure from vasoactive agents may improve flap perfusion. The purpose of this study was to evaluate the effect of commonly used vasopressors on flap circulation.

METHODS

The vertical rectus abdominis myocutaneous (VRAM) island flap was raised in five female pigs (38.2∼40.7 kg). Hemodynamic parameters were measured continuously by a carotid arterial catheter. A bi-directional transonic vascular doppler flow probe and Laser Doppler perfusion monitor (LDPM) unit were applied to record the continuous change in pedicle artery flow and microvascular perfusion following intravenous administration of dopamine (3, 5, 10µg/kg/minute), dobutamine (1.25, 2.5, 5µg/kg/minute), and norepinephrine (0.05, 0.1, 0.2µg/kg/minute).

RESULTS

Both microvascular perfusion and pedicle flow were generally proportional to the mean arterial pressure, and all three vasopressors improved flap perfusion and pedicle flow without deleterious effects. Norepinephrine showed the highest microvascular perfusion and dobutamine showed the highest pedicle flow rate. The mean blood pressure was the only statistically significant factor to affect both microvascular perfusion and pedicle flow (p < 0.0001).

CONCLUSION

Our results strongly suggest that the foremost three vasopressors can be used for flap surgery without deterioration, and that the maintenance of adequate systemic blood pressure is crucial for good flap circulation.

Enhanced Recovery for Breast Reconstruction Surgery

PURPOSE OF REVIEW

Enhanced recovery pathways are a well-described perioperative healthcare program involving evidence-based interventions. Enhanced recovery is designed to standardize techniques such as drug selection and nerve blocks in order to speed recovery and reduce overall hospital costs.

RECENT FINDINGS

A PubMed literature search was performed for articles that included the terms enhanced recovery and breast reconstruction surgery. The present investigation summarizes enhanced recovery literature related to breast surgery with a focus on breast reconstruction. Enhanced recovery considerations discussed in this review include patient education, preadmission optimization, perforator flap planning, anesthetic techniques, optimized fasting, venous thrombosis prophylaxis, early mobilization, and antimicrobial prophylaxis.

Paravertebral blocks and enhanced recovery after surgery protocols in breast reconstructive surgery: patient selection and perspectives

The management of postoperative pain is of critical importance for women undergoing breast reconstruction after surgical treatment for breast cancer. Mitigating postoperative pain can improve health-related quality of life, reduce health care resource utilization and costs, and minimize perioperative opiate use. Multimodal analgesia pain management strategies with nonopioid analgesics have improved the value of surgical care in patients undergoing various operations but have only recently been reported in reconstructive breast surgery. Regional anesthesia techniques, with paravertebral blocks (PVBs) and transversus abdominis plane (TAP) blocks, and enhanced recovery after surgery (ERAS) pathways have been increasingly utilized in opioid-sparing multimodal analgesia protocols for women undergoing breast reconstruction. The objectives of this review are to 1) comprehensively review regional anesthesia techniques in breast reconstruction, 2) outline important components of ERAS protocols in breast reconstruction, and 3) provide evidence-based recommendations regarding each intervention included in these protocols. The authors searched across six databases to identify relevant articles. For each perioperative intervention included in the ERAS protocols, the literature was exhaustively reviewed and evidence-based recommendations were generated using the Grading of Recommendations, Assessment, Development, and Evaluation system methodology. This study provides a comprehensive evidence-based review of interventions to optimize perioperative care and postoperative pain control in breast reconstruction. Incorporating evidence-based interventions into future ERAS protocols is essential to ensure high value care in breast reconstruction.