Laparoscopic cholecystectomy is the standard of care for patients with symptomatic gallstone disease.1–6
This technique, with all its advantages, has almost replaced open cholecystectomy in those with uncomplicated gallstone disease. During laparoscopic cholecystectomy various methods of cutting and coagulation are used, but at present, monopolar electrocautery is the preferred cutting method for laparoscopic surgery.12
The use of monopolar electrocautery is often associated with inadvertent tissue injury, as it generates intense collateral heat leading to tissue necrosis and ischemia. Most electrocautery injuries go unrecognized during surgery or present late.12
But injury such as gallbladder perforation during laparoscopic cholecystectomy may greatly hinder the surgical procedure by leading to inevitable spillage of bile and stones into the peritoneal cavity. This may prolong the surgical procedure and have serious consequences.13
Unlike monopolar electrocautery, ultrasonic dissection instrumentation denatures protein by means of ultrasonic vibrations at a frequency of 55 500 Hz with a vibratory excursion of 50–100 μm.14
The vibration transfers mechanical energy to the tissue, resulting in simultaneous cutting and coagulation. The vibrating ultrasonic dissector produces a coagulum of denatured protein and blood clot that occludes adjacent blood vessels and reduces bleeding. Vibration of the dissector scalpel blade does not generate as much heat as monopolar cautery or laser cautery, and the vibration in potential spaces results in cavitations, which may facilitate tissue dissection.14
No smoke is generated, only microaromized water droplets are produced, and no electric current is detected in the surgical field; therefore, this cutting method is also safe for use in patients with implanted pacemakers.15
The mist produced by the harmonic scalpel is rapidly absorbed by the peritoneal surface, and it does not require suctioning or releasing the smoke that is produced during monopolar electrocautery dissection.
Gallbladder perforation is reported to be the most frequent complication occurring intraoperatively during laparoscopic cholecystectomy.16
Perforation occurs in 13%–50% of patients who undergo laparoscopic cholecystectomy, and in 10%–40% of these patients, bile leakage and stone spillage are present.17
Laceration due to grasper traction and electrocautery dissection is the most common mechanism of gallbladder rupture during laparoscopic cholecystectomy.10
The overall incidence of gallbladder perforation in our study was 28.3% and differed significantly between the 2 groups (40.0% in the electrocautery group v. 16.7% in the ultrasonic dissection group, p
= 0.045). There was a 23.3% reduction in the perforation rate with the ultrasonic dissector. Reduction of gallbladder perforation during laparoscopic cholecystectomy using the ultrasonic dissector has also been reported in other studies.6,12,18,19
Bile leak was noted in all patients who had gallbladder perforation, but the incidence of stone spillage was 58.3% in the electrocautery group and 40.0% in the ultrasonic dissection group, which was not significant (p
= 0.62). Janssen and colleagues6
reported that the gallbladder perforation with stone spillage was 6 times higher in the electrocautery group than the ultrasonic dissection group. However, even if perforation occurred, stone spillage could still be prevented by quickly occluding the perforated site of the gallbladder with a grasper. The incidence of gallbladder perforation during laparoscopic cholecystectomy has been reported more often in patients with complications, such as acute cholecystitis, fibrotic gallbladder and dense adhesions in the Calot triangle.6
Ultrasonic dissection is the technique of choice for gallbladder dissection in patients with complications.6
Our study revealed a 14.23 times greater risk of gallbladder rupture in the presence of complications, and gallbladder perforation occurred in all patients with complications in the electrocautery group and in 33.3% of patients in the ultrasonic dissection group. This observation suggests that the ultrasonic dissector is a better device, especially in patients with complicated gallbladder disease.
In our study, 90.0% of the patients in the electrocautery group required lens cleaning during surgery, whereas only 63.3% of the patients required lens cleaning in the ultrasonic dissection group, and the mean number of times that lens cleaning was required per patient was twice in the electrocautery group and once in the ultrasonic dissection group (p = 0.004). The number of lens cleanings is very subjective, but the very need for lens cleaning (extracorporeal and intracorporeal) suggests the degree of difficulty and the duration of the surgical procedure.
Duration of surgery in our study was significantly shorter in the ultrasonic dissection group than the electrocautery group (27.20 min v. 34.37 min, p
= 0.001). The use of the ultrasonic dissector in laparoscopic cholecystectomy provides a superior alternative to monopolar electrocautery, as it is associated with shorter duration of surgery.12,18,20
Shorter mean duration of surgery in the ultrasonic dissection group may be attributed to several factors. The Harmonic Ace is a multifunctional instrument; it replaces 4 instruments routinely used in laparoscopic cholecystectomy: namely, the dissector, clip applier, scissors and electrosurgical hook or spatula. Finally, the activation of the ultrasonic dissector does not produce smoke and allows the surgeon to work in a clear operative field throughout the operation.
Cost is a concern with the routine use of a Harmonic scalpel in laparoscopic colecystectomy. Ours is a fully government-funded hospital, and the cost of all surgical procedures is subsidized, so there is no difference in the cost for use of Harmonic scalpel and monopolar cautery dissection. Otherwise, Harmonic scalpel use will be more costly.