br Surgical approaches and techniques Surgical removal
Surgical approaches and techniques Surgical removal of a substernal goiter is a challenging procedure; it can be performed safely via a cervical approach in most cases (> 90%), with a slightly higher complication rate than the average rate for cervical goiter thyroidectomy, especially concerning hypoparathyroidism and post-operative bleeding. The most significant criteria for selecting patients requiring sternotomy (< 10%) are CT features, in particular, the presence of an ectopic goiter, the thyroid gland volume, the extent of the goiter to or below the tracheal carina, and those suspected of malignancy. In our experience, more than 95% of substernal goiters can be resected via a low transverse incision, particularly in those with a cervical thyroid mass (secondary type). The blood supply of secondary substernal goiters almost always comes from the inferior thyroid vessels. After dissection and freeing of the cervical portion of the substernal goiter, the substernal part is easily delivered into the neck with gentle upward traction of the cervical thyroid and concomitant finger dissection, starting from the lateral surface, then to the lpa receptor of the goiter mass, even if the goiter is so large to reach the subcarinal level, and even in those with previous thyroidectomy (recurrent substernal goiter). Besides, we strongly recommend suture obliteration of the substernal dead space after resection of the goiter mass.
Surgical results and comorbidity and mortality A transverse collar incision is a simple and painless surgical wound, with much lower morbidity and mortality as compared with those after thoracotomy or median sternotomy approaches. The potential postoperative complications include vocal cord paralysis, hypoparathyroidism, and bleeding. Many authors have reported an incidence of complications after thyroidectomy for substernal goiters similar to that after standard thyroidectomy (for cervical goiter), except for postoperative temporary hypoparathyroidism. Intraoperative monitoring of recurrent laryngeal nerve may be helpful in preventing vocal cord paralysis. Such hypoparathyroidism occurs more often in surgery for substernal goiters (5%–10%) than in standard thyroidectomy. Most of patients can leave hospital within a few days after surgery. Symptoms such as stridor and dyspnea subside soon after surgery. Despite remarkable tracheal compression at the time of diagnosis, tracheomalacia never occurred after thyroidectomy in our previous experience. Noninvasive positive pressure ventilation may be used in the management of stridor and airway compromise following early extubation in patients with post-thyroidectomy tracheomalacia.24 Radiographically, all the deviated tracheas can resume normal midline position, and the diameter of the compressed tracheal lumina will increase to almost normal within 2–3 months after surgery.
Introduction Surgical management of the posterior fossa region containing such lesions as basilar tip aneurysms or retrochiasmatic craniopharyngiomas is challenging due to the complex neurovascular relationships. In addition, the presence of the posterior clinoid process (PCP) complicates further deep access to this area. Although the PCP serves as an indispensable part of anterolateral intracranial approaches, it has received less than proper attention and has been sparingly documented in the neurosurgical literature than its anterior counterpart, the anterior clinoid process, which has been widely studied. Awareness of the anatomical variations of the PCP and of its relationship to other skull base landmarks could help in safe surgical works, both microscopically and endoscopically. Our study is based upon the morphologic study of the clinoid regions in order to better introduce the conjoint association between the PCP and skull base surgery.
Materials and methods
Results The radiologic and anatomic morphology of all specimens was summarized in Table 1. The one specimen had a one-sided fused ACP-PCP image that presented in the cadaver as the ossified interclinoid ligament (Fig. 2). The rest of PCPs (seven out of eight dissections) were of discrete, nonfused type; here, we named the projection and spiculated shapes (Fig. 3). Five out of these seven PCPs were of the projection type, whereas two out of seven PCPs were of the spiculated type. The endoscope utilized the optic-carotid window to inspect the retrosellar region with no interference during the transcranial approach. But we found that the spiculated PCP might obscure the visualization of the in-line illumination in the transcranial approach. Hence additional drilling of the PCP, i.e., posterior clinoidectomy will be necessary when the approach is beyond the sellar region. In our study, one fusion and one spiculated PCPs impeded the transcranial approach to the retrosellar region. But all PCPs were on the way of the transclival approaches. So the PCP removal was supposed to be crucial in this extracranial approach. We assumed that posterior clinoidectomy facilitated the viewing of the retrosellar region and prepontine cisternal space. We tried to simulate the aneurysmal clipping surgery by applying a 7-mm aneurysmal clip (Sugita titanium, Tokyo, Japan) to the basilar trunk. Both approaches can allow endoscope-assisted clipping of the basilar artery (Fig. 4). However, we found that the working ability of the transcranial way largely exercised in the upper clival region whereas the transclival way compensated the lower half of the clival region. In our observation, the PCP plays a pistol role in maneuvering the endoscope in supratentorial posterior fossa operations when it reveals fusion and spiculated shapes. As for the extracranial transclival approach, it is necessary to remove PCPs to expose the corresponding area that can be reached by the transcranial one.