Vasopressor support vs. liberal fluid administration in deep inferior epigastric perforator (DIEP) free flap breast reconstruction – a randomized controlled trial

A systematic review of randomised controlled trials in breast reconstruction

BACKGROUND

For preference sensitive treatments, such as breast reconstructions, there are barriers to conducting randomised controlled trials (RCTs). The primary aims of this systematic review were to investigate what type of research questions are explored by RCTs in breast reconstruction, where have they been performed and where have they been published, and to thematise the research questions and thus create an overview of the state of the research field.

METHODS

Randomised controlled trials investigating any aspect of breast reconstructions were included. The PubMed database was searched with a pre-defined search string. Inclusion and data abstraction was performed in a pre-defined standardised fashion. For the purpose of this study, we defined key issues as comparison of categories of breast reconstruction and comparison of immediate and delayed breast reconstruction, when the thematisation was done.

RESULTS

A total of 419 abstracts were retrieved from the search. Of the 419, 310 were excluded as they were not RCTs concerning some aspect of breast reconstruction, which left us with 110 abstracts to be included in the study. The research questions of the included studies could more or less be divided into seven different themes inclusive of 2 key issues: Other issues - comparison of different categories of breast reconstruction, comparison of immediate and delayed breast reconstruction, surgical details within a category of breast reconstruction, surgical details valid for several categories of breast reconstruction, donor site management, anaesthetics, and non-surgical details. Only five studies compared key issues, and they all illustrate the challenges with RCTs in breast reconstruction.

CONCLUSIONS

A total of 110 publications based on RCTs in breast reconstruction have been published. Seven themes of research questions could be identified. Only five studies have explored the key issues. Better scientific evidence is needed for the key issues in breast reconstruction, for example by implementing a new study design in the field.

Bilateral Simultaneous Lumbar Artery Perforator Flaps in Breast Reconstruction: Perioperative Outcomes Addressing Safety and Feasibility

BACKGROUND

The lumbar artery perforator (LAP) flap has emerged as an excellent option for breast reconstruction, but its steep learning curve makes it less approachable. Furthermore, length of the operation, flap ischemia time, need for composite vascular grafts, complex microsurgery, multiple position changes, and general concern for safety has led experienced surgeons to stage bilateral reconstructions. In the authors' experience, simultaneous bilateral LAP flaps are feasible, but overall perioperative safety has not been fully explored.

METHODS

Thirty-one patients (62 flaps) underwent simultaneous bilateral LAP flaps and were included in the study (excluding stacked four-flaps and unilateral flaps). Patients underwent two position changes in the operating room: supine to prone and then supine again. A retrospective review of patient demographics, intraoperative details, and complications was performed.

RESULTS

The overall flap success rate was 96.8%. Five flaps were compromised postoperatively. The intraoperative anastomotic revision rate was 24.1% per flap (4.3% per anastomosis). The significant complication rate was 22.6%. The number of sustained hypothermic episodes and hypotensive episodes correlated with intraoperative arterial thrombosis ( P < 0.05). The number of hypotensive episodes and increased intraoperative fluid correlated with flap compromise ( P < 0.05). High body mass index correlated with overall complications ( P < 0.05). The presence of diabetes correlated with intraoperative arterial thrombosis ( P < 0.05).

CONCLUSIONS

Simultaneous bilateral LAP flaps can be performed safely with an experienced and trained microsurgical team. Hypothermia and hypotension negatively affect the initial anastomotic success. In this complex operation, a coordinated approach between the anesthesia and nursing team is paramount for patient safety.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

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.

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.

Monitoring free flaps and replanted digits via perfusion index -A proof of concept study

BACKGROUND

Early detection and treatment of vascular complications in replanted digits is essential for the survival. The perfusion index (PI) represents a marker of peripheral perfusion as it shows the ratio of pulsatile to non-pulsatile blood flow.

OBJECTIVE

To evaluate the feasibility and applicability of the PI as a monitoring tool for free flaps and replanted digits by measuring the inter- and intraindividual changes in PI.

METHODS

Five patients were postoperatively monitored according to intern standards by hourly clinical evaluation. Additionally, a pulse oximeter with SET-technology® (Masimo Radial 7, Masimo Corporation, Irvine, USA) was added with a LNCS® Red TFA-1 SpO2 sensor (Masimo Corporation, Irvine, USA) and respectively a LNCS® Neo-3 neonatal finger clip to evaluate the perfusion via PI and SpO2.

RESULTS

All patients showed sufficient perfusion in clinical controls. There was no detectable vascular complication during follow-up. Mean perfusion index was 0.93 with a median of 0.44. The patients showed a mean SpO2 of 90.59%with a median of 89.21%.

CONCLUSION

Our results show a great intra- and interindividual range of PI and SpO2. SpO2 provided an even greater range than PI. Trends in intraindividual PI changes may be a promising monitoring tool for free flaps and replanted digits.

The Adrenergic System in Plastic and Reconstructive Surgery: Physiology and Clinical Considerations

ABSTRACT

The primary organ systems and tissues concerning plastic and reconstructive surgery include the integument, vasculature, subcutis, and peripheral nerves, because these may individually or collectively be injured requiring reconstruction, or indeed be used in reconstruction themselves through grafts, flaps, or anastomoses. Adrenergic receptors are present throughout these anatomic components on the vasculature, adipose, platelets, immune cells, keratinocytes, melanocytes, fibroblasts, peripheral nerves, and tendons. Herein, the influence of adrenergic signaling on the physiology of anatomic components related to plastic surgery is discussed, along with clinical considerations of this systems involvement in procedures, such as free flap reconstruction, skin grafting, fat grafting, and other areas relevant to plastic and reconstructive surgery. Current evidence as well as potential for further investigation is discussed.

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.

Avoiding the night terrors: the effect of circadian rhythm on post-operative urine output and blood pressure in free flap patients

Multiple studies demonstrate the importance of goal-directed fluid regimens in avoiding complications. These regimens do not take account of circadian fluctuations in urine output (UO), MAP (mean arterial pressure) and pulse rate (PR). This is the first study that aims to demonstrate the effect of circadian rhythm on these haemodynamic parameters in post-operative patients with free flaps, as well as analysing clinicians' response to these variations. Retrospective analysis of 116 patients with free flaps. Records were assessed for UO, MAP, IV fluid infusion rate, oral fluid intake. Parameters were measured from 8 am to 8 pm (diurnal) and from 8 pm to 8 am (nocturnal) in the first 48 h post operatively. Patients with diabetes or hypertension were excluded. Mean diurnal UO rate (1.7 ml/kg/hr) was higher than nocturnal UO rate (0.7 ml/kg/hr); and mean diurnal MAP (93) was higher than nocturnal MAP (73.8). Mean diurnal IV infusion rate was 1.25 ml/kg/hr (lower) and mean nocturnal infusion rate 1.81 ml/kg/hr (higher). These differences were all statistically significant by paired student t-test (p < 0.05). This study demonstrates that circadian rhythm has a statistically significant impact on UO, MAP and PR. UO, MAP and PR are expected to dip overnight. This dip is normal and does not necessarily need to be treated by increasing IV fluids to avoid over filling of free flap patients.

Impact of opioid-free anesthesia on complications after deep inferior epigastric perforator flap surgery: A retrospective cohort study

This study measured the number of complications after deep inferior epigastric perforator (DIEP) flap reconstruction performed under opioid-free anesthesia (OFA) combined with goal-directed fluid therapy or opioid anesthesia with liberal fluid therapy (OA). This retrospective cohort study consisted of 204 patients who underwent DIEP flap reconstruction at AZSint Jan Brugge between April 2014 and March 2019. Primary outcomes were complications, according to the Clavien-Dindo classification and the length of hospital stay (LOS). The secondary outcomes were flap failure, postoperative nausea and vomiting (PONV), postoperative pain, postoperative opioid consumption, and postoperative skin flap temperature. OFA included a combination of dexmedetomidine, lidocaine, and ketamine without any opioid administered pre- or intraoperatively. OA included a combination of sufentanil and remifentanil. OFA patients received strict goal-directed fluid therapy, whereas OA patients received liberal fluids to maintain perfusion pressure. All patients except 7 (TIVA with remifentanil) received inhalation anesthesia combined with an infusion of propofol. Of the 204 patients, 55 received OFA and 149 received OA. There were no differences in major complications, but fewer minor complications in the OFA group (17.9% vs. 51.4% and P < 0.001). Flap failure occurred in three patients of the OA group. Six patients developed flap thrombosis (five OA patients and one OFA patient). OFA was associated with fewer postoperative opioids, shorter LOS, less PONV, and less pain. In patients without previous nausea, the PONV incidence was higher in the OA group than in the OFA group (12.7% vs. 43.6% and P < 0.001). Patients with previous nausea more frequently required postoperative opioids and had a nausea rate of 60.87%.

[Abdominoplasty without closed-suction drains: a randomised controlled trial]

INTRODUCTION

 There is insufficient scientific evidence from randomised controlled trials to support the routine use of closed-suction drains in body contouring procedures. The aim of this study was to evaluate cumulative seroma volume, length of hospital stay and complication rates in abdominoplasty patients without drains in direct comparison with a cohort receiving drains.

MATERIAL AND METHODS

 Abdominoplasty patients were prospectively randomised in two study groups with (MD) and without (OD) placement of closed-suction drains. Patients with a BMI ≤ 30 kg/m² undergoing horizontal or combined horizontal/vertical incision abdominoplasty were included. Scarpa's fascia was preserved during dissection. Exclusion criteria comprised simultaneous liposuction, coagulation disorders and ASA score ≥ 3. Cumulative seroma volume over a four-week follow-up period was assessed as the primary outcome measure. Secondary outcome measures were complications requiring surgical revision and length of hospital stay.

RESULTS

 This trial did not identify a statistically significant difference in cumulative seroma volume between the MD (30/53) and OD (23/53) cohorts in 53 patients (M_MD 493 ± SD 407 ml; M_OD 459 ± SD 624 ml; p = 0.812). However, a significantly shorter average length of hospital stay was observed in the OD population (M_MD 5.1 ± SD 1.4 d; M_OD 4.2 ± SD 1.5 d; p = 0.023). Complication rates were equal in both study groups (n_MD = 1; n_OD = 1).

CONCLUSION

 The results of this trial do not justify routine placement of closed-suction drains in abdominoplasty procedures (horizontal or combined horizontal/vertical incision) in the pre-obese patient cohort (BMI ≤ 30 kg/m²). Drain placement should be evaluated on an individual patient-specific basis.

Thromboelastometry for Assessing Risks of Free Flap Thrombosis in Patients Undergoing Microvascular Surgery

Introduction: Coagulation assessment is often missing in microvascular surgery. We aimed at evaluating the predictive value of thromboelastometry for free flap thrombosis in microvascular surgery patients. Materials and Methods: We enrolled 103 adult patients with traumatic injuries scheduled for microvascular free flap surgery into a prospective observational study. Thirty-six patients with recent trauma underwent surgery within 30 days (ES group), and were compared with 67 trauma patients who underwent surgery later than 30 days (late surgery, LS group) after the injury. Rotational thromboelastometry (RTE) was performed before surgery. Functional fibrinogen to platelet ratio (FPR) ≥ 42 was selected as the main hypercoagulability index. Free flap thrombosis was set as primary outcome. Thrombotic risk factors and duration of surgery related to free flap thrombosis were secondary outcomes. Statistical significance p < 0.05; not significant NS. Results: Six patients (16.7%) in the ES group and 10 (14.9%) in the LS group had free flap thrombosis (NS). In the entire cohort, free flap thrombosis rate increased in the presence of thrombogenic comorbidities (OR 4.059, CI 1.33-12.37; p = 0.014) and prolonged surgery times (OR 1.007, CI 1 - 1.012; p = 0.05). Although hypercoagulability occurred more frequently in the ES group (44.4%) than in the LS group (11.9%; p < 0.001), it was not associated with higher free flap thrombosis rate. In ES group patients with surgery times > 240 min, the risk of free flap thrombosis increased (OR 3.5, CI 1.16-10.6; p = 0.026) with 93.3% sensitivity and 86.7% specificity (AUC 0.85; p = 0.007). In contrast, in LS patients hypercoagulability increased the odds of free flap thrombosis (OR 8.83, CI 1.74-44.76; p = 0.009). Moreover, a positive correlation was found between FPR ≥ 42 and free flap thrombosis rate (r = 0.362; p = 0.003). In the LS group, the presence of thrombogenic comorbidities correlated with free flap thrombosis rate (OR 7, CI 1.591-30.8; p = 0.01). Conclusions: In LS patients with thrombogenic comorbidities, thromboelastometry supports the detection of hypercoagulability and predicts free flap thrombosis risk. In ES patients, postoperative hypercoagulability did not predict free flap thrombosis. Prolonged surgery time should be considered as a risk factor.

The effect of hemodilution on free flap survival: A systematic review of clinical and experimental studies

BACKGROUND

Acute normovolemic hemodilution (ANH) has been proposed as a microsurgical technique to improve blood flow in free flaps.

OBJECTIVE

Here, we present the first systematic review of clinical and experimental studies on the effect of ANH.

METHODS

We performed a systematic literature search of PubMed, Medline, the Cochrane Library, Google Scholar, and ClinicalTrials.gov using search strategies and a review process in agreement with the PRISMA statement and the Cochrane Handbook for systematic reviews of interventions. PICO criteria were defined before bibliometric processing of the retrieved articles, which were analyzed with the SYRCLE RoB tool for risk of bias and the GRADE scale for level of evidence.

RESULTS

We retrieved 74 articles from the literature search, and after processing according to PICO criteria, only four articles remained, all of which were experimental. The rating for risk of bias was uncertain according to SYRCLE RoB results, and the level of evidence was low according to GRADE evaluation.

CONCLUSIONS

There is no clinical evidence for the effect of ANH on microcirculation in free flaps, and experimental studies provide weak evidence supporting the use of hemodilution in reconstructive microsurgery.

Perioperative Fluid Resuscitation in Free Flap Breast Reconstruction: When Is Enough Enough?

Perioperative liberal fluid resuscitation (LFR) can result in interstitial edema and venous congestion and may be associated with compromised perfusion of free flaps and higher incidence of wound complications. We hypothesized that restrictive intraoperative fluid resuscitation improves flap perfusion and lowers the wound complication rate in free flap breast reconstruction.

Assessment of DIEP Flap Perfusion with Intraoperative Indocyanine Green Fluorescence Imaging in Vasopressor-Dominated Hemodynamic Support Versus Liberal Fluid Administration: A Randomized Controlled Trial With Breast Cancer Patients

BACKGROUND

Dogmatic denial of vasopressor agents for blood pressure regulation during free-flap surgery is associated with concomitant large-volume intraoperative fluid administration. Yet, the doctrinal banning of vasopressors during microvascular breast reconstruction still is a subject of controversy. Several retrospective observations have recently drawn attention to serious iatrogenic consequences of intravenous crystalloid overload in microsurgery such as thrombus formation and increased flap failure rates.

METHODS

This prospective randomized controlled trial investigated the potential effects of fluid-restrictive vasopressor-dominated hemodynamic support (FRV) compared with vasopressor-restrictive liberal fluid administration (LFA) on clinically relevant perfusion of the deep inferior epigastric perforator (DIEP) flap via intraoperative indocyanine green (ICG) fluorescence imaging. The primary end point of the study was quantitative assessment of the percentage of insufficiently perfused tissue (NP) on the overall flap. Major complications were assessed as secondary end points.

RESULTS

In 44 DIEP flap breast reconstructions after mastectomy, FRV circulatory support resulted in no statistically significant difference in total flap perfusion as detected via ICG fluorescence imaging in direct comparison with a traditional LFA strategy (NP_FRV, 31.8% ± 12.2% vs NP_LFA, 29.5% ± 13.3%; p = 0.559). One flap failure was registered with LFA, whereas no major complication occurred in the FRV cohort.

CONCLUSIONS

According to the results of this study, neither a norepinephrine concentration of 0.065 ± 0.020 μg/kg/min (FRV) nor fluid administration of 5.1 ± 2.2 ml/kg/h (LFA) has a clinically significant impact on microperfusion in a standard DIEP flap procedure for breast reconstruction. Consistent with the current literature reporting a rise in complications with intraoperative fluid over-resuscitation, one flap failure occurred in the LFA cohort.