The Shaw scalpel and development of facial nerve paresis after superficial parotidectomy

Neural outcomes after plasma knife dissection: a pathologic study and clinical correlation

BACKGROUND

The initial aim was to determine the rate of pathologic tissue damage when dissecting the rat sciatic nerve with either bipolar forceps or low-temperature tripolar plasma knife. The second aim was to determine the safety and effectiveness of the plasma knife during parotid surgery.

METHODS

A prospective, randomized, single-blind study was performed on 40 rat sciatic nerves dissected by either bipolar electrocautery with a cold knife or a plasma knife. Dissected nerves were excised and submitted blindly to pathology for analysis of nerve injury. The degree of nerve trauma was graded by the Carlander nerve injury classification. Separately, a review was performed on the facial nerve outcomes of 30 patients who underwent plasma knife parotidectomy.

RESULTS

No thermal or neural injury was noted in the 40 rat sciatic nerves dissected by either bipolar electrocautery or plasma knife (p = 1.0). Two plasma knife-dissected nerves (8%) demonstrated significant numbers of mast cells in the perineural soft tissue. In 30 patients undergoing plasma knife-parotidectomy, 10 (33%) had mild weakness of 1 or 2 preserved facial nerve branch postoperatively (House-Brackmann 2) that resolved within 1 month, whereas 2 (7%) had visible weakness in 1 branch (HB 3) that normalized after 3 months of follow-up.

CONCLUSION

Plasma knife nerve dissection seems to be a safe and effective alternative to conventional methods. This technique may confer some advantages over conventional methods with the ability to simultaneously cut and coagulate tissue with minimal thermal spread and electrical stimulation of adjacent neural structures.

Tissue Welding Forceps Usage in Superficial Parotidectomy: A Clinical Assessment

Tissue welding forceps (TWF) have been used effectively in a number of surgical procedures including blood vessel harvesting and tonsillectomy. Our objective was to assess the safety and efficacy of TWF usage in superficial parotidectomy. We performed a retrospective review of 25 patients between November 2002 and July 2006 who underwent superficial parotidectomy using TWF. The inpatient and outpatient records were reviewed for diagnosis, operative times, estimated blood loss, and postoperative facial paresis. Only one of the 25 patients (4%) who underwent superficial parotidectomy using TWF had transient postoperative facial weakness and no procedure had blood loss of greater than 150 cc. This initial evaluation suggests that use of TWF is safe in superficial parotidectomy and may help reduce the development of postoperative facial paresis.

Facial Nerve in Parotidectomy: A Topographical Analysis

OBJECTIVE

Establish normative data concerning parotidectomy and facial nerve dissection and determine the relationship between the length of the facial nerve dissected during parotidectomy and subsequent facial nerve paresis.

STUDY DESIGN

Prospective mapping of facial nerve during parotidectomy and comparison with postoperative facial nerve function.

METHODS

A prospective observational study of 78 patients who underwent 79 parotidectomy procedures. During each procedure, various topographical measurements were recorded. These measurements included the distance from the tragal pointer to the main trunk of the facial nerve, the distance to the pes anserinus, and length of each segmental branch dissected. In addition, a designation of the patient's tumor location was made by drawing a line from the ear canal to the nasal spine. Tumors above this line were designated anatomic zone A and those below the line were designated anatomic zone B. Finally, facial nerve function was quantified at a 1-week follow-up visit using the House-Brackmann Scale.

RESULTS

The distance from the main trunk of the facial nerve to the tragal pointer was significantly (P < .000) less than the previously accepted standard of 1 cm. The cervical and marginal mandibular branches had more nerve dissected, whereas the eye and forehead branches were the least dissected. Results of an independent t test and logistic regression (P = .01, both) indicated that patients with temporary facial nerve paresis had a significantly greater amount of nerve dissected than patients without temporary facial nerve paresis. Patients with short-term facial nerve dysfunction had significantly (P < .01) more total nerve dissected (136.73 mm vs. 94.73 mm) than patients without short-term facial nerve dysfunction. Patients with nerve dissection lengths at the third quartile (130.0 mm) were 3.8 times more likely to experience temporary facial nerve paresis than patients with nerve dissection lengths at the first quartile (64.5 mm).

CONCLUSIONS

The axiom that the main trunk of the facial nerve is located 1 cm from the tragal pointer may need to be modified to less than 1 cm. The cervical and marginal mandibular branches had more nerve dissected, whereas the eye and forehead branches were the least dissected. Facial nerve paresis after parotidectomy is associated with the length of the facial nerve dissected during the procedure. The greater the length of facial nerve dissected, the higher the chance of facial nerve paresis, albeit temporarily, in this particular series of patients.

Effects of steel scalpel, ultrasonic scalpel, CO2 laser, and monopolar and bipolar electrosurgery on wound healing in guinea pig oral mucosa

OBJECTIVE

The study's objective was to compare instrument performance and tissue healing when steel scalpel, ultrasonic scalpel, monopolar or bipolar electrosurgical instruments, or CO2 laser was used in an animal oral surgery model.

STUDY DESIGN

Prospective, blinded, randomized.

METHODS

Adult guinea pigs (N = 70) were randomly assigned to 5 groups (14 animals per group) for excision of 2-cm, full-thickness oral mucosa using steel scalpel, ultrasonic scalpel, monopolar or bipolar electrosurgical instruments, or CO2 laser. Postoperative pain was measured indirectly using weekly body weight changes. Animals from each group were killed on days 0, 7, 14, 21, and 28. Specimens were harvested for blinded histopathological study and tensile strength measurement. Instrument performance (hemostasis, tissue coagulation, tissue sticking) and wound healing (tissue re-epithelialization, degree of inflammation) were primary outcomes. Statistical analysis was performed using analysis of variance.

RESULTS

The ultrasonic scalpel was the best tool in controlling hemostasis, tissue coagulation, and tissue sticking. Significantly higher body weight gain ( P<.05) was noted at day 7 for monopolar and CO2 laser groups. Greatest tensile strength was seen in the steel scalpel and ultrasonic scalpel groups at the end of 28 days. Tissue re-epithelialization was fastest for the steel scalpel and ultrasonic scalpel groups (complete by day 7). Complete re-epithelialization of wounds of all treatment groups occurred by day 28. All groups had acute inflammation. Complete resolution of inflammation by day 14 took place in the steel scalpel and ultrasonic scalpel groups only.

CONCLUSION

Use of the ultrasonic scalpel produced faster re-epithelialization and greater tensile strength than laser or electrosurgical instruments, with results comparable to those seen with the steel scalpel.

Shaw scalpel in revision cochlear implant surgery

The use of traditional electrocautery is prohibited in revision or replacement cochlear implant surgery because of the concern for end organ tissue damage. Additionally, electrical current spread to the malfunctioning device could interfere with an accurate cause-of-failure analysis. Clinical reports have confirmed the utility of the Shaw scalpel for dermatologic, ophthalmic, and head and neck surgery. The Shaw scalpel is a thermally activated cutting blade that provides a bloodless field through immediate capillary and small vessel hemostasis. Avoidance of wound and flap complications is of primary concern in cochlear implant surgery. The long-term wound healing compared favorably to that of other surgical cutting instruments in several experimental reports. We have routinely used the Shaw scalpel in revision cochlear implant surgery and in primary surgery whenever electrocautery was contraindicated. We have retrospectively evaluated 22 cases in which the Shaw scalpel was used for cochlear implant revision and primary surgery. The chart review included patient demographics, the indication for surgery, the contraindication for electrocautery, intraoperative surgical notes, the wound healing evaluation, the evaluation for alopecia, and postoperative speech understanding. No significant complications occurred intraoperatively, and the long-term wound healing results were no different from those obtained with conventional surgical techniques. The explanted devices were undamaged, and valuable diagnostic information could be obtained. All patients performed at or better than their preoperative levels on speech recognition testing. Our results indicate that the Shaw scalpel is a relatively safe, easy-to-use, and effective instrument.

Bipolar scissors in facial plastic surgery

BACKGROUND

Many methods are available to the facial plastic surgeon for elevating and separating tissue, from cold steel to monopolar cautery to various laser-cutting technologies. Bipolar cautery has replaced monopolar cautery as the optimal hemostatic technique because of its decreased tissue damage and improved capabilities. Bipolar scissors concurrently offer a dissecting technique with hemostatic capability. Little exists in the otolaryngology literature on the use of bipolar scissors for soft tissue dissection.

OBJECTIVE

To describe our experience using bipolar scissors in a variety of facial plastic and reconstructive procedures.

SETTING

Tertiary care referral academic center.

DESIGN

We retrospectively reviewed 78 procedures performed using bipolar scissors between June 1997 and August 1999. In facial plastic cosmetic surgery, bipolar scissors were used 31 times for deep plane face-lifts and 16 times for endoscopic browlifts. In facial plastic reconstructive surgery, bipolar scissors were used in 15 radial forearm free flaps, 10 fibula osteocutaneous flaps, 3 rectus abdominis free flaps, and 3 latissimus dorsi myocutaneous free flaps.

RESULTS

In all procedures, bipolar scissors facilitated the dissection. By allowing for a drier field, less time was required to elevate the flap and obtain hemostasis. Complications were not increased compared with historical controls. In the harvesting of fibula osteocutaneous free flaps, use of bipolar scissors allowed harvesting without use of a tourniquet.

CONCLUSION

Bipolar scissors, a new technology in facial plastic surgery, allow the same control as sharp dissection and provide simultaneous hemostasis.

Surgery of the salivary glands

Surgery of the salivary glands evolved rapidly after a greater understanding of the anatomy and pathologic processes affecting them was achieved. This article reviews the general and neurovascular anatomy of the major salivary glands. Understanding the anatomy of the salivary glands is a cornerstone of competent salivary gland surgery. The surgical techniques, potential pitfalls of surgery, and avoidance of postsurgical complications have been highlighted. Recent advances in surgical techniques are also presented.