Harmonic ACE Ultrasonic Shears (da Vinci)
Harmonic instruments cut and coagulate tissue using ultrasonic blade motion. The historical da Vinci Harmonic ACE assembly and current handheld Harmonic products are different configurations. Their platform compatibility, vessel limits and disposable components must be checked separately.[1][2]
Identify the Configuration
| Configuration | What the primary device documents establish |
|---|---|
| Historical da Vinci Harmonic ACE | FDA clearance K093217 describes 5 and 8 mm configurations for specified earlier da Vinci systems, with a reusable proximal housing and disposable distal shaft/grip insert, connected to the specified Ethicon generator and handpiece. It does not establish compatibility with every current robot or a universal ten-procedure life for the whole assembly.[1] |
| Handheld/laparoscopic ACE+7 | A separate instrument with a 7 mm vessel-coagulation indication in Advanced Hemostasis mode. This indication must not be transferred to a legacy robotic ACE or to every Harmonic model/mode.[2] |
The traditional robotic Harmonic lacks the wristed tip of many da Vinci graspers and scissors. Bedside use of a compatible handheld instrument through an assistant port is the usual workaround. It keeps the robotic arms free for wristed instruments. In a 10-case robotic gastrectomy series, console time was 251 minutes with assistant-port ultrasonic shears and 306 minutes with robotic devices only (single centre, not randomized). Check the actual system, instrument availability and team roles.[1][3][14]
Mechanism and Thermal Effects
Ultrasonic motion plus tissue compression produces cutting and coagulation without using the patient as an electrosurgical RF current circuit. A patient return electrode is not required for this ultrasonic action. The blade and passive jaw nevertheless become hot, and avoiding electrosurgical coupling does not remove thermal injury or plume hazards.[2][4]
In an experimental study using bovine mesentery and lamb veins, the tested ACE blade reached about 191°C during cutting and took 35.7 seconds to cool to the study's 60°C endpoint; the passive jaw took 25.4 seconds. Another tested device had a longer active-blade cooling time, so ACE was not universally the “slowest to cool.” These are experimental measurements and not a 30-second clinical clearance rule, and 60°C is not a guarantee of safe tissue contact.[4]
Avoid contact between recently activated surfaces and vulnerable adjacent structures. A low reported temperature at a tissue seal does not describe the maximum blade temperature. No single published millimeter margin establishes safety beside a nerve, ureter or bowel.
Vessel Sealing: Bench Data
Vessel size matters more than the manufacturer's label. These are ex vivo porcine or colorectal-specimen experiments, so treat them as bench comparisons and not as clinical failure rates.
| Study | Setting | Finding |
|---|---|---|
| Harold 2003[8] | Porcine arteries, 16 per size group | Mean burst pressure, electrothermal bipolar sealer versus ultrasonic shears: 601 versus 205 mmHg at 4–5 mm and 442 versus 175 mmHg at 6–7 mm (p = 0.0001). No difference at 2–3 mm. |
| Okhunov 2018[9] | 246 porcine vessels | Harmonic Scalpel Ace Plus had the lowest burst pressure among five devices: 571 mmHg in medium (5.1–7 mm) and 254 mmHg in large (7.1–9 mm) arteries. Seal failure occurred in 20% of medium and 40% of large arteries. Harmonic Ace +7, Caiman 5 and LigaSure had no failures up to 9 mm. All pressures that did hold exceeded 250 mmHg. |
| Noble 2011[10] | 93 ex vivo mesenteric vessels, mean diameter about 1 mm | Harmonic Ace, LigaSure and LOTUS burst pressures did not differ significantly. Depth of thermal damage was 1.95 mm with Harmonic Ace and 3.37 mm with LigaSure (p < 0.001). |
Use ultrasonic shears alone for small vessels and mesentery. For arteries above about 5 mm, use a sealer rated for that size, clips or ligatures. These data used older handheld models, so check the current instructions for the exact device.
Reconstructive Applications
Potential tasks include selected soft-tissue and small-vessel division during abdominal exposure or diversion. Preserve bowel and ureteral vascular supply, isolate the intended tissue and use the vessel limit for the actual model and activation mode. Clips, ligatures or other vascular control remain appropriate when the tissue or vessel is outside that indication.
Cold sharp dissection and selective nonthermal hemostasis may be preferable around neurovascular bundles, ureter, fine reconstructive planes or prosthetic components. Neither ultrasonic nor bipolar energy has a universal safety advantage for these structures.
Technique and Device Instructions
The ACE+7 instructions illustrate why the model and mode matter: power, tissue tension, grip, blade features and tissue type all affect the result; its 7 mm indication specifies Advanced Hemostasis. The instructions prohibit contact with metal while activated and abrasive cleaning of the blade. Use the exact device instructions for assembly, cleaning, cooling and activation; these ACE+7 details are not a substitute for a legacy robotic ACE manual.[2]
Keep the working end visible, identify nearby structures and avoid activating on unintended tissue. Ultrasonic devices can generate smoke or vapor; a small randomized colpotomy study found better visibility than monopolar energy, not absence of plume or elimination of occupational exposure.[5]
Evidence and Choice of Energy Device
Kong's 2017 robotic gastrectomy feasibility study compared 17 cases with the articulating EndoWrist Vessel Sealer against 52 concurrent cases with ultrasonic shears. It was prospective but not randomized. Operative time, blood loss and complications did not differ. C-reactive protein on day 2 (8.06 versus 11.7) and albumin on day 5 (3.51 versus 3.32) favored the sealer.[6] In a randomized three-arm trial of laparoscopic distal gastrectomy (n = 174), day-2 CRP was lower with advanced bipolar sealing than with ultrasonic shears (9.03 versus 11.12), as was blood loss (26.3 versus 43.7 mL); operative time, hospital stay and complications did not differ.[12] These are gastric-surgery surrogates. They do not show better urologic recovery.
Randomized colorectal data favor either energy device over monopolar scissors. In 61 patients having laparoscopic left colectomy, dissection took a median 90 minutes with ultrasonic shears, 105 with a bipolar sealer and 137 with monopolar scissors (p < 0.001). The authors estimated lower cost with either device at 200 cases a year.[11] An umbrella review of ten systematic reviews in surgical oncology reported 25–29 minutes shorter operative time with Harmonic devices, with very low to moderate certainty. Its authors were employed or sponsored by the manufacturer.[13]
The older Cochrane review of laparoscopic colectomy included six heterogeneous trials with 446 participants and could not determine an overall best energy instrument. Device and operating-room costs depend on local use and procedure; savings from one operation should not be assumed for another.[7]
For current robotic sealers, remember the separate limits: SynchroSeal up to 5 mm; Vessel Sealer Extend up to 7 mm. A product's vessel limit and articulation are selection factors, not proof that it is best for every case; see the vessel-sealer comparison.
See also: Energy Devices, LigaSure, Maryland Bipolar, Monopolar Curved Scissors.
References
1. US FDA. Da Vinci Harmonic ACE Device, K093217. 2010. 510(k) summary and indications.
2. Ethicon / J&J MedTech. Harmonic ACE+7: Advanced Hemostasis indication and instructions excerpt. Manufacturer product information; brochure with instructions excerpt.
3. Hirahara N, Matsubara T, Hayashi H, Tajima Y. Features and applications of energy devices for prone robot-assisted minimally invasive esophagectomy: a narrative review. J Thorac Dis. 2022;14(9):3606–3612. doi:10.21037/jtd-22-559.
4. Kim FJ, Sehrt D, da Silva RD, et al. Evaluation of emissivity and temperature profile of laparoscopic ultrasonic devices (blades and passive jaws). Surg Endosc. 2015;29(5):1179–1184. doi:10.1007/s00464-014-3787-0.
5. Choi C, Do IG, Song T. Ultrasonic versus monopolar energy-based surgical devices in terms of surgical smoke and lateral thermal damage (ULMOST): a randomized controlled trial. Surg Endosc. 2018;32(11):4415–4421. doi:10.1007/s00464-018-6183-3.
6. Kong SH, Kim TH, Huh YJ, et al. A feasibility study and technical tips for the use of an articulating bipolar vessel sealer in da Vinci robot-assisted gastrectomy. J Laparoendosc Adv Surg Tech A. 2017;27(11):1172–1179. doi:10.1089/lap.2017.0093.
7. Tou S, Malik AI, Wexner SD, Nelson RL. Energy source instruments for laparoscopic colectomy. Cochrane Database Syst Rev. 2011;(5):CD007886. doi:10.1002/14651858.CD007886.pub2.
8. Harold KL, Pollinger H, Matthews BD, et al. "Comparison of ultrasonic energy, bipolar thermal energy, and vascular clips for the hemostasis of small-, medium-, and large-sized arteries." Surg Endosc. 2003;17(8):1228–30. doi:10.1007/s00464-002-8833-7
9. Okhunov Z, Yoon R, Lusch A, et al. "Evaluation and comparison of contemporary energy-based surgical vessel sealing devices." J Endourol. 2018;32(4):329–37. doi:10.1089/end.2017.0596
10. Noble EJ, Smart NJ, Challand C, et al. "Experimental comparison of mesenteric vessel sealing and thermal damage between one bipolar and two ultrasonic shears devices." Br J Surg. 2011;98(6):797–800. doi:10.1002/bjs.7433
11. Hubner M, Demartines N, Muller S, et al. "Prospective randomized study of monopolar scissors, bipolar vessel sealer and ultrasonic shears in laparoscopic colorectal surgery." Br J Surg. 2008;95(9):1098–104. doi:10.1002/bjs.6321
12. Park JH, Kong SH, Berlth F, et al. "Comparison of perioperative outcomes between bipolar sealing, ultrasonic shears and a hybrid device during laparoscopic gastrectomy for early gastric cancer: a prospective, multicenter, randomized study." Gastric Cancer. 2023;26(3):438–50. doi:10.1007/s10120-023-01365-6
13. Cheng H, Clymer JW, Sadeghirad B, et al. "Performance of Harmonic devices in surgical oncology: an umbrella review of the evidence." World J Surg Oncol. 2018;16(1):2. doi:10.1186/s12957-017-1298-x
14. Kakeji Y, Kuroda D, Nakamura T, et al. "Ultrasonic shears assistance can shorten the console time in robotic gastrectomy for early gastric cancer." BMC Res Notes. 2015;8:443. doi:10.1186/s13104-015-1432-1