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

Flying high?-Exploring the effect of red bull on blood pressure after microsurgical breast reconstruction in a randomized controlled trial

BACKGROUND

A sufficiently high blood pressure (BP) is essential for flap perfusion after microsurgical breast reconstruction. However, postoperative hypotension is common after these procedures. Perioperative volume overload may increase flap-related complications, and postoperative vasopressor use may be limited depending on institutions. Red Bull has been shown to increase BP in several studies. We aimed to evaluate the effect of Red Bull on perfusion-related variables after microsurgical breast reconstruction.

METHODS

We conducted a multicenter, prospective, randomized controlled trial. Female patients undergoing unilateral microsurgical breast reconstruction from June 2020 to October 2022 were randomly assigned to the intervention or control groups. The intervention group received 250 ml of Red Bull 2 h after surgery and twice on postoperative day (POD) 1. The control group received 250 ml still water at the respective intervals. BP was measured using a 24-hour monitoring device. Vasopressor use, fluid balance, and flap outcomes were compared.

RESULTS

One hundred patients were included in the study. Both groups were comparable concerning age, body mass index, and caffeine consumption. Mean arterial and diastolic BP were significantly higher in the Red Bull group after the second drink in the morning of POD1 (p-value = 0.03 and 0.03, respectively). Vasopressor use was similar, with a tendency for less postoperative etilefrine in the Red Bull group (p-value = 0.08). No flap loss was observed.

CONCLUSIONS

We observed increased mean arterial and diastolic BP in the Red Bull group after the second drink. Red Bull may be a useful adjunct after microsurgical breast reconstruction.

LEVEL OF EVIDENCE

I, therapeutic.

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.

[Breast Reconstruction Strategies in Case of Planned Radiotherapy]

INTRODUCTION

The ideal technical and chronological approach of breast reconstruction in case of planned radiotherapy after mastectomy (post-mastectomy radiotherapy, PMRT) continues to be controversially discussed.

METHODS

The authors analysed the MEDLINE Database PubMed for relevant studies concerning PMRT and breast reconstruction. The main theses from these publications were extracted and summarised.

RESULTS

An implant-based approach is the least invasive technique for immediate breast-mound formation in a PMRT setting. Reconstruction in a PMRT setting with a two-stage expander-implant technique or expander-implant-autologous procedure can provide good to excellent cosmetic outcomes. In contrast to the implant-based approach, autologous reconstruction methods provide an improved quality of life as well as haptic and sensory advantages and are usually associated with lower complication rates. PMRT after autologous reconstruction can have a negative impact on the autologous tissue. A delayed autologous approach can be advantageous and should be generally favoured in high-risk patients.

CONCLUSION

Factors influencing a meticulous planning of breast reconstruction including PMRT are surgical, aesthetic and patient characteristics, quality of life, preference and expectation. Ideally, PMRT is completed before autologous reconstruction to avoid radiation-associated side-effects on the final reconstructive result. If PMRT is likely, but potentially not necessary, an immediate-delayed procedure may be of advantage.

Real-time tissue perfusion assessment using fluorescence imaging topography scanning system: A preclinical investigation

BACKGROUND AND OBJECTIVES

We previously developed a real-time fluorescence imaging topography scanning (RFITS) system for intraoperative multimodal imaging, image-guided surgery, and dynamic surgical navigation. The RFITS can capture intraoperative fluorescence, color reflectance, and surface topography concurrently and offers accurate registration of multimodal images. The RFITS prototype is a promising system for multimodal image guidance and intuitive 3D visualization. In the current study, we investigated the capability of the RFITS system in intraoperative fluorescence vascular angiography for real-time assessment of tissue perfusion.

STUDY DESIGN/MATERIALS AND METHODS

We conducted ex vivo imaging of fluorescence perfusion in a soft casting life-sized human brain phantom. Indocyanine green (ICG) solutions diluted in dimethyl sulfoxide (DMSO) and human serum were injected into the brain phantom through the vessel simulating tube (2 ± 0.2 mm inner diameter) by an adjustable flow peristaltic pump. To demonstrate the translational potential of the system, an ICG/DMSO solution was perfused into blood vessels of freshly harvested porcine ears (n = 9, inner diameter from 0.56 to 1.27 mm). We subsequently performed in vivo imaging of fluorescence-perfused vascular structures in rodent models (n = 10). 5 mg/ml ICG solutions prepared in sterile water were injected via the lateral tail vein. All targets were imaged by the RFITS prototype at a working distance of 350-400 mm.

RESULTS

3D visualization of 10 µg/ml ICG-labeled continuous moving serum in the brain phantom was obtained at an average signal-to-background ratio (SBR) of 1.74 ± 0.03. The system was able to detect intravenously diffused fluorescence in porcine tissues with an average SBR of 2.23 ± 0.22. The RFITS prototype provided real-time monitoring of tissue perfusion in rats after intravenous (IV) administration of ICG. The maximum fluorescence intensity (average SBR = 1.94 ± 0.16, p < 0.001) was observed at T_peak of ~30 seconds after the ICG signal was first detected (average SBR = 1.19 ± 0.13, p < 0.01).

CONCLUSIONS

We have conducted preclinical studies to demonstrate the feasibility of applying the RFITS system in real-time fluorescence angiography and tissue perfusion assessment. Our system provides fluorescence/color composite images for intuitive visualization of tissue perfusion with 3D perception. The findings pave the way for future clinical translation.

Objective photographic assessments and comparisons of immediate bilateral breast reconstruction using deep inferior epigastric perforator flaps and implants

Background

The increasing number of bilateral breast cancer patients has been accompanied by a growing need for bilateral mastectomy with immediate reconstruction. However, little research has investigated the complications and aesthetic outcomes related to bilateral reconstruction. Therefore, we analyzed retrospective data comparing the outcomes of bilateral reconstruction using deep inferior epigastric perforator (DIEP) flaps or implants.

Methods

This study included 52 patients (24 DIEP group and 28 implant group) who underwent bilateral mastectomy with immediate reconstruction between 2010 and 2020. Patient demographics, surgical characteristics, and complications were recorded. The difference between the left and right position of the nipple-areolar complex with respect to the sternal notch point at the clavicle was measured, and breast symmetry was evaluated.

Results

The average weight of breasts reconstructed with DIEP flaps (417.43±152.50 g) was higher than that of breasts with implants. The hospitalization period and operation time were significantly longer in the DIEP group. Early complications were significantly more common in the implant group (36.53%) than in the DIEP group. The angles between the nipples and the horizontal line were 1.09°±0.71° and 1.75°±1.45° in the DIEP and implant groups, respectively.

Conclusions

Although the surgical burden is lower, breast reconstruction using implants requires greater attention with respect to implant positioning, asymmetry, and complications than DIEP flap reconstruction. DIEP flap reconstruction has a prolonged operation time and a high risk of flap failure, but yields excellent cosmetic results and does not require intensive follow-up. Patients should be consulted to determine the most suitable option for them.

Influence of intraoperative vasopressor use on indocyanine green fluorescence angiography: first evaluation in an experimental model

Intraoperative indocyanine green (ICG) fluorescence angiography has gained popularity and acceptance in many surgical fields for the real-time assessment of tissue perfusion. Although vasopressors have the potential to preclude an accurate assessment of tissue perfusion, there is a lack of literature with regards to its effect on ICG fluorescence angiography. An experimental porcine model was used to expose the small bowel for quantitative tissue perfusion assessment. Three increasing doses of norepinephrine infusion (0.1, 0.5, and 1.0 µg/kg/min) were administered intravenously over a 25-min interval. Time-to-peak fluorescence intensity (TTP) was the primary outcome. Secondary outcomes included absolute fluorescence intensity and local capillary lactate (LCL) levels. Five large pigs (mean weight: 40.3 ± 4.24 kg) were included. There was no significant difference in mean TTP (in seconds) at baseline (4.23) as compared to the second (3.90), third (4.41), fourth (4.60), and fifth ICG assessment (5.99). As a result of ICG accumulation, the mean and the maximum absolute fluorescence intensity were significantly different as compared to the baseline assessment. There was no significant difference in LCL levels (in mmol/L) at baseline (0.74) as compared to the second (0.82), third (0.64), fourth (0.60), and fifth assessment (0.62). Increasing doses of norepinephrine infusion have no significant influence on bowel perfusion using ICG fluorescence angiography.

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.

Aesthetic Applications of Radiofrequency: Lymphatic and Perfusion Assessment

Background:

The use of radiofrequency in aesthetics has increased in popularity since the early 2000s. To date, there have been limited studies investigating the effect of thermal energy secondary to radiofrequency treatment. The purpose of this study was to evaluate perfusion and lymphatic assessment tools pre and post bipolar and fractional radiofrequency treatment.

Methods:

A retrospective IRB-approved study was conducted between January 2019 and April 2019. Patients who were independently deemed appropriate candidates for radiofrequency soft tissue remodeling were evaluated. Diagnostic perfusion and lymphatic imaging obtained were reviewed using indocyanine green (SPY, Stryker) and optical coherence tomography (Vivosight OCT).

Results:

A total of 63 patients were treated during the study period, of which 37 had diagnostic perfusion and lymphatic imaging. Average patient age was 47 (STD 12), 95% (35/37) of patients were women, and no patients were active smokers. In total, 27% (10/37) of patients were post-surgical patients with recurrent laxity, 32% (12/37) did not have enough skin laxity to justify traditional excisions procedures, and 41% (15/37) may have been candidates for excisional procedures but were willing to accept more moderate results to avoid excisions surgery. Indocyanine green perfusion and lymphatic assessment for bipolar and fractional radiofrequency, as well as optical coherence tomography pre and post radiofrequency, did not show compromise from thermal injury.

Conclusions:

This study supports safety of radiofrequency in terms of preservation of tissue perfusion and lymphatic drainage. This correlated to our low clinical incidence of burns, prolonged swelling, or tissue ischemia.

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%.

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.