Comparative Analysis of Electrocautery Versus LigaSure Energy-based Device for Anterolateral Thigh Free Flap Dissection

Abstract

Background:

The anterolateral thigh (ALT) free flap is widely used in reconstructive surgery, but intramuscular perforator dissection remains technically demanding and time-consuming. Electrocautery may cause collateral thermal injury and slower dissection rates. Advanced bipolar energy devices, such as LigaSure, offer precise vessel sealing with reduced thermal spread, potentially enabling faster and more controlled dissection. This study aimed to directly compare electrocautery with LigaSure during ALT flap harvest, evaluating dissection efficiency and operative duration.

Methods:

A combined retrospective–prospective study was conducted. Group A retrospectively analyzed 20 ALT flaps by a single surgeon (10 with electrocautery, 10 with LigaSure), comparing flap harvest time. Group B prospectively analyzed 10 ALT flaps, where 2 surgeons each alternately dissected a perforator within the same flap using either electrocautery or LigaSure, facilitating direct comparison. Primary outcomes were flap harvest time and perforator dissection speed (time per centimeter of perforator length).

Results:

LigaSure significantly reduced flap harvest time. In group A, flap harvest time was shorter with LigaSure versus electrocautery. In group B, perforator dissection was significantly faster with LigaSure, averaging 11.5 versus 39.4 minutes with electrocautery. Normalized to perforator length, LigaSure achieved 1.61 minutes per centimeter compared with 6.29 minutes per centimeter with electrocautery, approximately 3.9 times faster (P < 0.05).

Conclusions:

LigaSure significantly enhances ALT flap dissection efficiency, especially along the intramuscular perforator course, thereby reducing flap harvest time. Its adoption can streamline workflow and improve procedural consistency in ALT flap harvest.

Takeaways

Question: Does LigaSure improve efficiency, safety, and outcomes versus electrocautery?

Findings: LigaSure enables precise intramuscular dissection with reliable vessel sealing and minimal thermal spread. It improves efficiency with faster dissection and reduced operative time, while maintaining flap integrity. Fewer instrument changes and reduced need for clips enhance workflow, performing well across varying perforator anatomy.

Meaning: Reduced thermal spread allows safer dissection near perforators with better control. Increased speed and streamlined handling improve efficiency and consistency, making LigaSure a versatile and reliable option for anterolateral thigh flap harvest.

INTRODUCTION

The anterolateral thigh (ALT) flap is a versatile and extensively used technique for reconstructive surgery, especially in addressing complex soft-tissue defects. A critical step in ALT flap harvest involves intramuscular dissection of perforator vessels through the vastus lateralis muscle, a technically challenging procedure due to the intricate and variable anatomy.¹ Efficient and precise perforator dissection directly influences operative duration and patient outcomes.²

Electrocautery, including monopolar and bipolar devices, is widely used for surgical dissection, including perforator vessel identification and separation. Despite its reliability, electrocautery has several inherent drawbacks, such as collateral thermal spread, reduced precision, and prolonged dissection times during intricate vessel navigation.³ In contrast, advanced energy-based devices, such as LigaSure (Medtronic), have emerged as alternatives offering precise vessel sealing capabilities, reduced thermal injury, and potentially faster and more controlled dissection.⁴

Previous studies in other surgical specialties have demonstrated the benefits of energy-based devices. For instance, their use in head and neck reconstruction showed approximately a 35% reduction in flap dissection time, fewer surgical clips, and decreased intraoperative blood loss.⁵ Similarly, ultrasonic energy devices in breast reconstruction have proven to be superior to monopolar cautery in terms of precision and postoperative recovery.⁶ Although these findings suggest broad applicability, adoption of advanced energy devices for ALT flap perforator dissection remains variable, influenced by institutional preferences, surgeon training, and device accessibility.

This study aimed to directly compare electrocautery and LigaSure devices in ALT flap harvest, analyzing flap harvest time, perforator dissection speed per centimeter, and broader implications for operative planning and resource optimization. By quantifying these metrics in a clinical setting, this investigation seeks to provide evidence-based insights for improved surgical efficiency and informed decision-making in microsurgical practice.

MATERIALS AND METHODS

Study Design

This combined retrospective–prospective comparative study evaluated the impact of dissection technique on operative efficiency during ALT free flap harvest. The study was conducted at the Division of Plastic & Reconstructive Surgery, Sengkang General Hospital, from January to May 2025, with institutional review board clearance obtained (institutional review board no. 2020-2854).

The study comprised 2 components:

• Group A (retrospective): Analysis of total flap harvest time from surgical data comparing 10 ALT flaps dissected using electrocautery (2020–2021) with 10 ALT flaps dissected using LigaSure (2024). The same senior surgeon performed all flap dissections in this group.

• Group B (prospective): Intraoperative comparison of perforator dissection times between electrocautery and LigaSure conducted by 2 plastic surgeons, each alternatively using LigaSure or an electrocautery device on separate perforators within the same patient, across 10 consecutive ALT flap cases.

Patient Selection

All patients undergoing ALT free flap harvest for soft-tissue reconstruction of complex diabetic foot wounds were eligible for inclusion. Patients with prior surgery, radiation treatment at the donor site, or known vascular anomalies were excluded to maintain uniform complexity in flap dissection.

Data Collection and Surgical Protocol

Group A

Retrospective data, including total operative time from skin incision to pedicle transection (start of ischemia time), were collected from electronic medical records (Citrix), intraoperative documentation, and anesthetic charts. Potential confounders such as wound size and the number of perforators dissected were documented to control for variability. Patients with incomplete data or intraoperative complications unrelated to flap dissection were excluded.

Group B

Prospective data were collected from January to May 2025 for 10 consecutive patients undergoing ALT free flap harvest. Cases with only a single identifiable perforator were excluded, as direct device comparison would not be feasible. Procedures were performed under standardized conditions using general anesthesia.

During each ALT flap harvest, all perforators within the planned flap dimensions were identified subfascially via a lateral approach. Perforators were identified at their point of entry into the muscle. Perforators measuring 1 mm or more were preserved for flap perfusion, with completion of the medial incision.

All perforators were first deroofed to reveal the perforator/pedicle anatomy. A minimum of 2 perforators were selected for further dissection based on the anatomy.

For the intramuscular portion of the dissection, 2 plastic surgeons each dissected 1 perforator, alternating the device used. For example, in 1 case, surgeon A used ligatures for dissection, whereas surgeon B used diathermy.

Ligature dissection was performed as follows. The selected perforator was skeletonized with deliberate preservation of a small cuff of surrounding soft tissue (muscle/fascia). Dissection was performed along both sides of the perforator, followed by release from the underlying soft tissue. The perforator was then elevated in a distal-to-proximal direction. (See Video [online], which displays intramuscular perforator dissection in an ALT flap using LigaSure, showing the lateral and posterior dissection after completion of the anterior dissection to define the perforator course. LigaSure enables precise dissection close to the perforator with minimal thermal spread and without clips, allowing efficient flap harvest with less remnant tissue and shorter operative time.)

Video 1. This is a video shows intramuscular perforator dissection in an ALT flap using Ligasure. The anterior surface was previously dissected to trace the perforator’s full course. Lateral and posterior dissections demonstrate the device’s ease of handling without assistance. Ligasure’s reduced thermal spread allows precise placement near the perforator, enabling circumferential muscle tissue dissection with minimal remnant tissue. No clips were required, eliminating instrument changes. These factors collectively reduce operative time whilst achieving.

gox-14-e7888-s001.mp4 ^{(89.8MB, mp4)}

Indocyanine green (ICG) angiography was performed after elevation of the perforators and pedicle to confirm perforator preservation and patency (Fig. 1). In the subsequent free flap procedure, the sequence was reversed—2 perforators were dissected, with surgeon B using ligature and surgeon A using diathermy—to ensure a balanced comparison of techniques between surgeons. Electrocautery settings were standardized at level 15 for both cutting and coagulation, whereas LigaSure was operated at default settings. The alternating dissection approach between the surgeons and devices aimed to minimize learning curve bias and operator fatigue.

Fig. 1.

ALT perforator dissection. A, Yellow arrows point out all the perforators in the flap and the distal 2 perforators showing the complete course after intramuscular dissection. B, Intraoperative ICG showing patent perforators before pedicle ligation at the donor site, indicating no iatrogenic damage during dissection.

For each perforator, the dissection duration from the start of intramuscular dissection to complete skeletonization at its origin from the main pedicle was timed by an independent observer using a digital stopwatch. The length of each dissected perforator was measured intraoperatively with a sterile ruler. Primary outcomes included absolute dissection time per perforator and dissection speed (minutes per centimeter of perforator length) (Fig. 2).

Fig. 2.

A photograph of intraoperative measurement of dissected perforator length.

Statistical Analysis

Data analysis was performed using Python 3.11. Descriptive statistics, including mean, SD, and ranges, were calculated. Welch t test was used to compare groups, accommodating unequal variances. Statistical significance was set at a P value less than 0.05.

RESULTS

Patient Demographics (Group A)

The mean age was 58 years (range 46–69 y) in the electrocautery group and 56.7 years (range 47–69 y) in the LigaSure group, with a combined gender distribution of 15 men and 5 women. No significant demographic differences existed between subgroups.

Total Flap Harvest Time Comparison: Group A

The mean flap harvest time was significantly shorter using LigaSure (178.7 ± 51.9 min) compared with electrocautery (290.9 ± 40.9 min; P = 0.001), representing a mean reduction of approximately 112 minutes. No significant differences were noted in wound area. The number of perforators dissected per flap was significantly higher in the LigaSure group, indicating that operative time differences were primarily due to the dissection technique (Table 1).

Table 1.

Comparison of Total Flap Harvest Time by Using LigaSure and Electrocautery

Group	Flap Harvest Time, min, Mean ± SD	Wound Size, cm2	Perforators
Electrocautery	290.9 ± 40.9	50.9 ± 30.3	2.0 ± 0.6
LigaSure	178.7 ± 51.9	71.6 ± 43.3	3.6 ± 1.6
P	0.001	0.25	0.014

Patient Demographics (Group B)

Group B comprised 10 patients (7 men, 3 women), with a mean age of 55.2 years (range 42–79 y, SD ±11.4 y).

Perforator Dissection Time Comparison: Group B

LigaSure markedly reduced dissection time. The mean perforator dissection duration was 39.4 minutes with electrocautery and 11.5 minutes with LigaSure. Normalized per centimeter of perforator length, LigaSure dissection averaged 1.61 minutes per centimeter compared with 6.29 minutes per centimeter for electrocautery, a significant 3.9-fold improvement (P < 0.05). Despite longer average perforator lengths dissected with LigaSure (mean 8.9 versus 5.7 cm for electrocautery), LigaSure demonstrated significantly faster and more consistent results (Tables 2, 3).

Table 2.

Comparison of Time Taken to Dissect per Centimeter of Perforator Between 2 Devices by Different Surgeons

	Surgeon 1 (Electrocautery)	Surgeon 2 (LigaSure)	P
Mean perforator length, cm	6.5 ± 1.6	7.2 ± 1.6	0.34
Mean dissection time, min	39.4 ± 12.0	10.5 ± 5.2	<0.0001
Mean time per centimeter	6.47 ± 1.8	1.61 ± 0.7	<0.0001
Mean reduction in time		28.9 min (73% faster)

Table 3.

Advantages and Disadvantages of LigaSure Versus Electrocautery

	LigaSure	Electrocautery
Advantages	• Faster dissection, ~4× • Minimal thermal speed (≤2 mm) • Simultaneous seal and division • Less need for clips/ligatures • Safe and small perforators • Shorter learning curve • Reduces operative time	• Wide available, affordable • Effective hemostasis • Familiar technique
Disadvantages	• Higher cost (~USD 700/case) • Limited availability globally • Single use in many settings • Less tactile feedback • Repeated activation in dense tissue	• Greater thermal spread (3–5 mm) • Risk of charring, nerve damage • Collateral thermal injury risk

In both groups, there was no flap failure. The donor sites were all closed primarily with 2 weeks of incisional negative pressure wound therapy. There were no donor site complications such as seroma or wound dehiscence.

DISCUSSION

The ALT flap is a cornerstone reconstructive option, highly valued for its versatility, reliability, and utility in addressing complex soft-tissue defects. Regardless of the chosen harvest plane (suprafascial or subfascial), intramuscular dissection is a key step in flap dissection, as approximately 85% of perforators are of musculocutaneous origin. It remains a critical yet technically challenging step due to significant anatomical variability. Meticulous dissection at this stage is vital for preserving perforator integrity and ensuring flap viability.^3,4

Electrocautery, traditionally the primary tool for surgical dissection, offers notable advantages such as wide availability, affordability, and effective hemostatic control. Its primary mechanism involves high-frequency electrical currents that coagulate or incise tissues. However, electrocautery carries inherent drawbacks, including significant thermal spread (3–5 mm in depth), tissue charring, and risk of inadvertent damage to critical structures such as nerves and perforators.⁵ These limitations pose distinct challenges in microsurgical scenarios, where precision, tissue preservation, and minimal collateral damage are paramount.⁶

In contrast, LigaSure, an advanced bipolar energy-based device, achieves effective hemostasis through a precise combination of energy and mechanical pressure, denaturing vessel wall collagen and elastin. The subsequent protein cross-linking results in reliable vessel sealing, minimizing thermal damage and tissue trauma.^7,8 Our combined retrospective and prospective analyses demonstrate significant benefits of LigaSure use in ALT flap harvest: notably, marked reductions in operative time without compromising safety or precision.

In the retrospective arm (group A), LigaSure use resulted in a significant operative time reduction averaging 112 minutes compared with electrocautery, with a significantly higher number of perforators dissected. Importantly, this benefit was observed independently of potential confounding variables such as wound size, microvascular anastomoses performed, or wound closure, underscoring the direct impact of the dissection tool itself. These findings parallel earlier reports from head and neck oncology and breast reconstruction literature, where energy-based devices consistently demonstrated shorter operative durations, reduced thermal injury, and comparable safety profiles.^9,10 Notably, our study uniquely focuses on ALT flaps harvested specifically for complex diabetic foot reconstructions, a patient subgroup in which reducing operative time and minimizing complications are critical for favorable outcomes.

The prospective evaluation (group B) further substantiated LigaSure’s superiority through intrapatient comparative dissections performed by 2 surgeons. LigaSure consistently enabled significantly faster perforator dissection, with an almost 4-fold gain in efficiency compared with electrocautery. This performance advantage likely reflects LigaSure’s ability to coagulate and divide tissue simultaneously, its limited thermal spread (≤2 mm), and the reduced need for adjunctive clips or ligatures¹¹ (see Video [online]).

Beyond speed, our findings indicate that LigaSure supports safe and efficient dissection not only of larger perforators, but also of small and delicate perforators with a caliber of approximately 1 mm. This was facilitated by deliberately preserving a small cuff of surrounding soft tissue around each perforator, which provides 2 key benefits: (1) thermal insulation that reduces the risk of heat-related injury during dissection, and (2) improved handling of small-caliber perforators, enhancing visualization and enabling safer manipulation. Postdissection ICG angiography consistently demonstrated good perfusion through individual perforators, including those measuring approximately 1 mm (Fig. 3). This real-time visual confirmation supports that LigaSure use does not compromise the vascular integrity of small perforators.

Fig. 3.

Small-caliber perforator dissection. A, Four perforators with diameters of 1, 3, 1, and 2 mm from left to right. B, ICG showing good flow of the 4 perforators.

Furthermore, the consistent perfusion observed on ICG imaging provides objective validation of safety and increases confidence in the reproducibility of this technique for microsurgical reconstruction. This safety and ease-of-use profile may be particularly valuable in resource-constrained settings or high-volume centers with limited trained assistance and may help shorten the learning curve for perforator dissection using a standardized approach.

Earlier literature across various surgical disciplines has underscored the advantages of energy-based devices such as LigaSure, Harmonic Scalpel, and Thunderbeat in improving dissection efficiency and reducing intraoperative morbidity.^12,13 However, these reports have not focused exclusively on intramuscular perforator dissection in ALT flaps. The present study is therefore the first to evaluate LigaSure specifically in this context, isolating its impact on perforator dissection speed and overall operative efficiency. This highlights the novelty of our work and extends the evidence base to the microsurgical domain, where precision, consistency, and time economy are of paramount importance.

LigaSure, despite its demonstrable advantages, presents certain limitations that warrant careful consideration before recommending its routine use in perforator dissection. The most significant drawback is its high cost, particularly in institutions where the handpiece is considered single-use. With device prices reaching approximately US $700 per case in our center, its incorporation into standard practice may be prohibitive in budget-restricted settings or in regions with limited access to advanced energy platforms. Device availability also varies widely, and many training programs, especially in low- and middle-income countries, may not have consistent exposure to LigaSure, limiting early familiarization among trainees. Although thermal spread is reduced compared with electrocautery, precise handling remains essential, as activation too close to the perforator can still result in microthermal injury, particularly in small-caliber perforator vessels. In addition, LigaSure provides less tactile feedback than traditional sharp or fine bipolar dissection, which may feel counterintuitive to surgeons accustomed to it. Thick or dense muscle bundles may occasionally require repeated activation, momentarily interrupting the flow of dissection in narrow anatomical planes. Finally, exclusive reliance on energy-based devices risks diminishing proficiency in conventional perforator dissection techniques, underscoring the importance of maintaining competency in both techniques.

Our observations reinforce LigaSure’s potential as an optimal tool for ALT flap dissection. Its integration into microsurgical practice can lead to safer, quicker procedures without increased technical complexity. The standardization of this technique could thus facilitate broader adoption, optimize operative resource use, and enhance overall patient safety.

CONCLUSIONS

LigaSure significantly enhances ALT flap perforator dissection efficiency, markedly reducing both perforator-specific and overall operative durations. Importantly, these improvements are achieved without compromising flap safety, tissue integrity, or technical ease. Wider adoption of LigaSure for flap harvest, particularly in high-volume, resource-limited, and academic centers, can improve operative outcomes and surgeon training effectiveness, making its routine integration into microsurgical practice highly advantageous.

DISCLOSURE

The authors have no financial interest to declare in relation to the content of this article.