Retropharyngeal space

Surgical anatomy

1. Retropharyngeal space Dr Safika Zaman, Post graduate trainee, Dept of ENT & Head-Neck Surgery VIMS, RKMSP

2. Topic of discussion Anatomy & Contents Functional anatomy Lesions Investigation Retropharyngeal abscess Retropharyngeal lymph nodes Retropharyngeal haematoma summary

3. Compartments of neck

4. Boundaries Anterior: buccopharyngeal fascia Posterior margin: alar fascia. The anterior space is the "true" retropharyngeal space. Posterior space is the  danger space   . combined spaces as one functional unit, As the fascia is very thin, radiographical differentiation is not possible.

5. Boundaries Lateral margins: deep layer of the deep cervical fascia carotid and parapharyngeal space.

6. Boundaries Superior: skull base. Inferior: fusion of alar fascia with the middle layer of the deep cervical fascia- T4 vertebral body

7. Contents areolar fat lymph nodes only in the suprahyoid region (lateral and medial retropharyngeal) small vessels. Functional importance: allow free movement of the pharynx on the vertebral column during swallowing, respiration, speech and exercise.

8. Lesions Primary : lipoma, liposarcoma , synovial sarcoma. Direct spread and metastasis: nasopharyngeal carcinoma, SCC of pharyngeal, laryngeal, sinonasal origin, Lymphoma, melanoma, esthesioneuroblastoma , chordoma , primary spinal tumour.

9. Fluid collection in retropharyngeal space Foreign body ingestion, Hematoma, angioedema, Retropharyngeal lymphadenitis, Vertebral osteomyelitis, Kawasaki disease, Calcific tendinitis of the longus colli muscle, Cystic tumor caused by lymphatic malformation

10. Investigation Routine blood investigation Radiological – X-RAY CT-Scan MRI PET-CT. FNAC /Biopsy

11. X-RAY(mainly done in retropharyngeal space infection) soft tissue swelling as more than 7 mm at C2 and more than 14 mm at C6. Generally, the anteroposterior diameter of the prevertebral soft tissue space in children should not exceed that of the contiguous vertebral body. Image source- medscape

12. Debnam JM, Guha-Thakurta N. Retropharyngeal and prevertebral spaces: anatomic imaging and diagnosis.  Otolaryngol Clin North Am . 2012;45(6):1293-1310. doi:10.1016/j.otc.2012.08.004

13. CT -Scan Acute conditions. Bone assessment Lung assessment Less than 1mm slide.

14. CT- Scan of retropharyngeal abscess

15. CT-Scan of RPS Lipoma & ICA

16. CT Scan of nasopharyngeal ca ( a ) Axial contrast-enhanced CT shows a large nasopharyngeal carcinoma(star); ( b ) axial contrast-enhanced CT shows thickened right RPS (star)extending across the midline;

17. MRI Tumour extent. Breech in tissue planes Lymph node status: size , shape , signal. Tissue of origin Involvement of neuro-vascular structures.

18. Normal MRI

19. MRI AJR 2011; 196:W433–W437 0361–803X/11/1964–W433 © American Roentgen Ray Society

20. MRI https://www.wjgnet.com/1949-8470/full/v2/i5/159.htm

21. PET-CT Neck nodes of unknown primary origin. Staging T3 & T4 Equivocal findings on CT & MRI Response to treatments

22. PET - CT Contrast enhanced CT scan (a) showing a large right sided oropharyngeal lesion. PET scan identified a small FDG-avid retropharyngeal (RP) lymph node (arrow) in the contralateral neck (b) equivocal on CT alone. This necessitated delivery of high tumoricidal doses to the involved retropharyngeal nodal region that would have otherwise received only prophylactic doses as low-risk elective volume. Image source – indian journal of cancer.

23. FNAC Du C, Ying H, Zhang Y, Huang Y, Zhai R, Hu C. Treatment for retropharyngeal metastatic undifferentiated squamous cell carcinoma from an unknown primary site: results of a prospective study with irradiation to nasopharyngeal mucosa plus bilateral neck.  Oncotarget . 2017;8(26):42372-42381. doi:10.18632/oncotarget.16344

24. Biopsy Patients with metastatic neck lymph nodes with unknown primary persistently raised tumour markers a normal nasopharynx on endoscopy inconclusive biopsy results

25. Retropharyngeal abscess Early recognition and aggressive management of RPA are essential because it still carries significant morbidity and mortality. The mortality rate may be as high as 40-50% in patients in whom serious complications develop.

26. Etiology of Retropharyngeal abscess Children Nodes atrophy with age Suppurative process in lymph nodes Sourse of infection is nose , nasopharynx,sinuses,adenoids Adults Usually caused by penetrating blunt trauma. Instrumentation like endoscopy Extension of infection from adjacent spaces.

27. Presentation Most of the abscess occurs before the age of 6. Children: fever, irritability, poor oral intake, neck lump ,torticollis,drooling . Adults: sore throat , odynophagia , dysphagia, nasal obstruction, respiratory distress, swelling in posterior pharyngeal wall.

28. Management of retropharyngeal abscess

29. Management of retropharyngeal abscess Key is to protect the airway Antibiotic: broad spectrum antibiotics. The Sanford Guide to Antimicrobial Therapy recommends adding empiric vancomycin to the regimen if the patient is in a high-risk group. Vancomycin or linezolid to cover MRSA

30. Management of Retropharyngeal abscess Trans-oral drainage – for majority of non complicated cases. Vertical incision is given on the most fluctuant point Trans-cervical drainage- lateral extension of abscess, repeat drainage. Image guided aspiration.

31. Retropharyngeal abscess transoral drainage: to localise the abscess by first aspirating it before incision and drainage. Make an incision through the posterior pharyngeal wall mucosa, and open the abscess with blunt dissection. Transcervical drainage :transverse cervical skin incision, raising subplatysmal flaps to expose the neck and dissecting along the anterior border of the sternomastoid . The sternocleidomastoid muscle and carotid sheath are then retracted laterally and blunt dissection is done upto the hypopharynx to open the retropharyngeal space abscess.

32. Complication of retropharyngeal abscess Airway obstruction Mediastinitis Pleural involvement Epidural abscess Sepsis Acute respiratory distress syndrome   Erosion of the second and third cervical vertebrae

33. Complication of retropharyngeal abscess Cranial nerve deficits (IX-XII) Septic thrombosis of jugular vein or hemorrhage secondary to erosion into carotid artery . Compression of carotid artery and internal jugular vein   Facial nerve palsy    

34. Retropharyngeal lymph nodes Image source-Wiki

35. Retropharyngeal lymph nodes Primary sites: carcinoma of head and neck thyroid cancer oesophagus cancer Most frequent metastasis is from nasopharyngeal cancer. FNA with the guidance of ultrasound, CT or MRI was utilized to obtain histological diagnosis of retropharyngeal masses.

36. Retropharyngeal lymph nodes in Nasopharyngeal ca RPLN are involved early in nasopharyngeal cancer, because they are primary draining LN of nasopharynx. Only 5% of patients may suffer from isolated nodal failure. Persistent nodal diseases : Patients who have persistently enlarged neck nodes 3 months after completion of radiotherapy.

37. Retropharyngeal lymph nodes in Nasopharyngeal ca Primary therapy is IMRT. Brachytherapy techniques: can be used for treatment of nodal failure in conjunction with surgical resection of the nodal metastasis. Radical neck dissection is considered as the standard of care for management of nodal failures.

38. Retropharyngeal hematoma In patients with cervical spine trauma it is possible for a hematoma to form in RP. Usually presents with progressive dyspnoea. Can be a life threatening emergency Other than acute trauma retropharyngeal hematomas related with anticoagulant therapy, iatrogenic injury, infections, foreign body ingestion. post spinal cord surgery

39. Retropharyngeal hematoma Detected with CT Scan or MRI. Management is conservative, if large enough may require tracheostomy & surgical drainage. Park JH, Jeong EK, Kang DH, Jeon SR. Surgical Treatment of a Life-Threatening Large Retropharyngeal Hematoma after Minor Trauma : Two Case Reports and a Literature Review.  J Korean Neurosurg Soc . 2015;58(3):304-307. doi:10.3340/jkns.2015.58.3.304

40. Retropharyngeal hematoma Vertebral artery ruptures manifesting as hoarseness Chih -Jen Yang a , Sheng-Yao Cheng b , Cheng-Chung Cheng c , Chi- Tun Tang d , Shih-Hung Tsai a ,

41. summary Potential space. Surrounded by vital structures May be a route of spread of infection. Early involvement in nasopharyngeal cancer. Trauma may happen during endoscopic or blunt procedures. Haematoma may form after neck trauma. Accurate and timely intervention will prevent complication. Also a route for surgical approach for spinal surgery.