Application of surgical navigation in styloidectomy for treating Eagle’s syndrome

Figures & data

Table 1 Comparison of relevant indexes between navigation-assisted operation and the usual operation $\left(\overline{x}\pm \text{SD}\right)$

	Average amount of bleeding (mL)	Duration of operation (minutes)	Duration of hospitalization (days)	Length of resected SP (mm)
Navigation cases (n=12)	22.50±8.54*	40.35±11.81*	2.06±0.71*	21.93±14.26
Conventional cases (n=12)	45.70±9.86	76.60±23.43	3.92±0.76	19.23±5.06

Note:

* P<0.01.

Abbreviation: SP, styloid process.

Table 2 VAS score before and after the navigation aided styloidectomy $\left(\mathrm{n}=12,\overline{x}\pm \text{SD}\right)$

Preoperative VAS	Postoperative VAS	P-value
5.22±1.76	1.83±0.64	0.0082

Abbreviation: VAS, visual analog scale.

Figure 1 Preoperative analysis of the ESP in navigation workstation.

Notes: Patient’s 3D-CT data were input into the navigation workstation to locate and measure the SP precisely, which showed its length was 40.8 mm (A). The virtual ESP was clearly seen using the software iPlan, and the resection spot was marked with green, while the residual was marked with red (B).
Abbreviations: 3D-CT, three-dimensional computed tomography; ESP, elongated styloid process; SP, styloid process.

Figure 2 Intraoperative application of surgical navigation to orient the elongated SP.

Notes: After the registration process was completed, a pointer was used to find the tip of SP using the guide of the images shown in the navigation machine’s screen (A). The green line denotes planned resection site in SP. Red color indicates the residual SP. Intraorally, the pointer showed the appropriate mucosa incision site that was closest to the SP (B).
Abbreviation: SP, styloid process.

Figure 3 The intraoperative navigation was applied to expose the ESP by intraoral approach.

Notes: The pointer was inserted into the intraoral wound and the virtual resection site was found using the guide of the images shown in the navigation machine’s screen (A). The green lines denote planned resection site in SP. Red color indicates the residual SP. The corresponding real resection spot was clearly exposed by the intraoral approach (B, white arrow).
Abbreviations: ESP, elongated styloid process; SP, styloid process.

Figure 4 Images for preoperative analysis of the ESP and the virtual surgery plan.

Notes: 3D-CT showed that the patient had a giant styloid process in the left side, which explained her discomfort symptoms (A). A virtual surgery plan was made in the navigation workstation (B). The green line denotes planned resection site in the SP. Red color indicates the giant ESP.
Abbreviation: 3D-CT, three-dimensional computed tomography; ESP, elongated styloid process; SP, styloid process.

Figure 5 During the surgery, a fine round bur was matched with the navigation system so that it could be used as an EM pointer and its track could simultaneously be seen on the screen.

Notes: The bur had reached the planned resection site of SP (A). The green lines denote planned resection site in SP. Red color indicates the residual SP. The white arrow indicates the exposed styloid process by small cervical approach (B).
Abbreviations: EM, electromagnetic; SP, styloid process.

Figure 6 The resected giant elongated styloid process and the small cervical skin scar after extraoral approach.

Notes: The styloid process was excised in integrity (A). The small cervical skin wound healed well after 1 month and the patient was satisfied with the cosmetic result (B).