The orbit is fragile and susceptible to traumatic injuries, and TPI accounts for 30–50% of eye trauma . Surgical managements of TPI have always been challenging due to the closeness of trauma to vital structures like foramina opticum and cavernous sinus . There are several reports on the cerebrovascular complications caused by either initial injury or the surgical intervention to remove the foreign body . CTA and DSA are very helpful for the preoperative surgical planning for foreign body removal and correct diagnosis of vascular complications. If cerebrovascular traumas are indicated, foreign body removal should be arranged either after endovascular treatment or performed in the catheterization procedure rooms. Otherwise, the bleeding during or after removal of the foreign body would be catastrophic.
Wood is the most commonly encountered organic foreign body in TPI. Generally, CT detection of wood may be difficult as its signal would be hypoattenuating in the acute phase, which resembles that of air on CT. But unlike air, wood also has a geometric shape, which might be helpful for differential diagnosis. Besides, the attenuation of wood on CT will change from isoattenuating in the subacute phase to hyperattenuating in the chronic phase. Although bamboo stick is a kind of wood, there is still not much knowledge on the radiological characteristics of a bamboo stick as the intraorbital foreign body [2, 4]. Because of the physical nature of the bamboo (soft and fragile), incomplete removal by direct retraction in the emergency room is highly likely . However, complete removal of organic foreign bodies such as bamboo is important as any remaining pieces could cause an inflammatory response and even severe infection. Also, incomplete removal of the organic foreign body might also lead to massive bleeding due to the erosion of major artery by chronic inflammation process . CT bone windows with a width of −1000 HU and a soft tissue window level of −500 HU have been suggested to better identify wooden foreign body and MR would further support the existence of organic foreign bodies by capturing the associated inflammation process .
The foreign body causing TPI could penetrate into the brain through either the orbital roof, the superior orbital fissure, or the optic canal . Open surgery via transorbital, transcranial, or combination of both has been used to remove the residual intraocular or intraorbital foreign body . Also, nasal and sinus passages with a nasal endoscopy have also been applied to remove intraorbital foreign body [6, 9, 10]. For our case, instead of using transorbital or transcranial open surgery, a percutaneous endoscopic procedure was chosen to remove the deeply located foreign body. The rationales are as flows: 1. Surgical injury has been minimised as the endoscope could be inserted through the primary penetrating pathway to approach the foreign body, and all surgical instruments were operated within the endoscopic sheath. 2. Constant saline irrigation supplied by the endoscopic system could reduce the venous oozing and keep a clear visual field. 3. A wide variety of grasping forceps is available to ensure the efficient removal of the deeply located foreign bodies while causing minimal tissue damage during the removal. 4. After the successful aneurysm embolization, the risks of its rupture due to endoscopic manipulation are low. 5. The one-month clinical history suggested the wooden foreign body (bamboo stick) might become soft, which makes it easier to be removed piece by piece from the endoscope working canal. To the best of our knowledge, this is the first report on applying the percutaneous endoscopic technique to the removal of an orbital-cranial residual wooden foreign body.
To conclude, the percutaneous endoscopic technique provides better visualization of the foreign body via a minimally invasive approach, and the success of current case suggests this technique could be the treatment of choice for similar patients with intraorbital-cranial retention of the foreign body after TPI.