Essay: Delayed onset huge refractory multiloculated cervical psedomeningocele after retromastoid craniectomy

ABSTRACT
Pseudomeningoceles after posterior fossa surgery pose a technical challenge to operating neurosurgeons. Cervical pseudomeningocele is unique in that herniation of neural tissue into pseudomeningocele sac produces catastrophic complications. Patient usually presents with postural headache. Treatment includes extrinsic compression, csf diversion followed by primary operative dural repair if refractory.In our case report we present a rare complication of delayed onset huge refractory multiloculated cervical psedomeningocele after retromastoid craniectomy which was surgically repaired.Detailed review of literature regarding its pathogenesis and a technical note of surgical repair is included.
Key words : delayed,cervical ,pseudomeningocele
INTRODUCTION
Pseudomeningocele is an abnormal collection of cerebrospinal fluid lined by fibrous membrane that communicates with the subarachnoid space. This was first reported by Hyndman and Gerber in 1946(1).The terms ‘meningocele spurious’, ‘pseudocyst’ or ‘false cyst’, have also been used to describe the condition(2).Pseudomeningoceles can be congenital,idiopathic,post traumatic or post surgical. Majority are often asymptomatic. Headache is the most common presenting symptom.
Csf collects in surrounding tissue when csf pulse pressure exceeds local tissue interstitial pressure(3).The fistula track usually contain a flap of tissue which act as a valve allowing csf to flow in one direction only leading to gradual increase in size following each cardiac cycle(3).The cavity is lined by fibrous membrane instead of leptomeningeal lining hence called pseudomeningocele(3). Cervical pseudomeningocele is unique in that herniation of neural tissue produces catastrophic complications(4).
Treatment modalities include extrinsic compression, csf diversion followed by primary operative dural repair if refractory.
CASE REPORT
Our patient was a 35 yr old female presented with left cp angle tumour of size 4??4 cm associated with severe left sensorineural deafness .CT showed brillianty enhancing tumour in left cp angle region(fig1)
Fig1: Preoperative contrast MRI showing 5??4cm cp angle lesion.
She was taken up for retromastoid retrosigmoid craniectomy in lateral position under general anaesthesia. Complete excision of tumour was done.Post operative period was uneventful except for grade 2 House brackmann facial palsy.Patient was discharged on day 10 after suture removal without any evidence of csf leak.Post operative CT scan showed complete tumour removal with no evidence of pseudomeningocele (fig2)
Fig2: Immediate post operative CT scan showing complete tumour removal with no evidence of pseudomenigocele
Two month later she was readmitted with huge tense swelling beneath the surgical scar along with neck pain and postural headache . From the history we found that the swelling was gradually increasing in size over the past I month.She was afebrile with no evidence of csf leak ouside.
On examination a swelling of size10??10cm which was fluctuant and transilluminant was found beneath the scar(fig3)
Fig3: Preoperative picture showing pseudomeningocele with healed intact wound.thick white arrow showing pseudomeningocele
No fresh neurological deficit was found.There was no clinical evidence hind brain herniation like pyramidal signs,lower cranial nerve palsy .
CT scan showed huge pseudomeningocele(fig 4)
Fig4: CT scan showing huge refractory pseudomeningocele
After getting informed written consent lumbar drain was put under strict aseptic condition.since the swelling did not decrease in size considerably following continous lumbar drainage, the patient was planned for open repair of dural fistula after informed written consent.
OPERATIVE FINDINGS:
The incision was put over the same surgical scar.The pseudomeningocele sac was dissected out and opened to find a multiloculated cavity with glossy inner membrane.(Fig 5)
Fig5: Multiloculated pseudomeningocele(long white arrow) with the small defect(small white arrow)
A small opening of size 4??4mm was seen at the lower end of dural incision.(Fig6)
The margins of the fistula was found fibrosed.We tried primary repair of the defect but was not able to able to close primarly(Fig6).We excised the fibrotic tissue and enlarged the dural opening(Fig7)
Fig 6:Craniectomy site after excision of pseudomeningocele sac.Trying to suture the small defect primarily
Fig 7: Small defect is enlarged after excising the fibrotic periphery of small defect
The enlarged fistula was then closed by patch repair using occipital fascia along with fat and muscle.(Fig8)
Fig8: The enlarged defect is closed using autologous dural substitute obtained from occipital fascia.
This was reinforced with pericranial onlay patch also.Intraoperative valsalva maneuver showed no csf leak.Wound was closed in layers with prophylactic continous lumbar drainage.Post operative CT scan showed complete resolution of pseudomeningocele(Fig9)
Fig9: Post operative CT scan after repair of dural leak and excision of pseudomeningocele sac.
Lumbar drain was removed on 3rd day.patient was discharged of day 10 with no evidence of pseudomeningocele(Fig10)
Fig10: post operative picture showing no pseudomeningocele
DISCUSSION
Pseudomeningocele is an abnormal collection of cerebrospinal fluid lined by fibrous membrane that communicates with subarachnoid space. Pseudomeningocele was first reported by Hyndman and Gerber in 1946 (1). The terms ‘meningocele spurious’, ‘pseudocyst’ or ‘false cyst’, have also been used to describe pseudomeningoceles(2). Pseudomeningoceles can be congenital,idiopathic,post traumatic or post surgical. Congenital pseudomeningoceles are usually associated with neurofibromatosis and marfan syndrome(1). Traumatic cervical pseudomeningocele can occur in young patients following brachial plexus injury due to direct injury to duramater causing cerebrospinal fistula(5). Muscular weakness from nerve injury can promote growth of the pseudomeningocele sac.Postoperative pseudomeningoceles may result from a tear in the duramater and pia- arachnoid that is unnoticed and is left open during surgery(6).CSF extravasates into the paraspinal soft-tissue space. The CSF may be absorbed initially but, after progressive fibrosis of the surrounding pseudocapsule,csf is absorbed less readily, resulting in pseudomeningocele formation(6).
PRESENTATION
Patients with pseudomeningoceles present most often with postural headache as a result of reduced intracranial pressure following reduction of csf volume(7). Some pseudomeningoceles present as fluctuant transilluminant mass that enlarges with coughing and sneezing(8).
PATHOGENESIS
Dural defects cause csf to collect in the surrounding tissue when csf pulse pressure exceeds interstitial pressure of surrounding tissue(3).The fistula track may contain a flap of tissue which act as a valve allowing csf to flow in one direction only leading to gradual increase in size during each cardiac cycle(3).The cavity is lined by fibrous membrane instead of leptomeningeal lining hence called pseudomeningocele. Rare reports of serious complication of herniation of neural tissue are reported(4).
MANAGEMENT
The management of pseudomeningocele is controversial particularly in asymptomatic patients. Optimal management is dependent upon many factors, including sac size, location and symptoms(5). Small pseudomeningoceles with minimal symptoms require no treatment. The conservative management in asymptomatic patients was accepted because even large pseudomeningoceles ‘scar down’ and resolves over time.
Treatment includes extrinsic compression ,csf diversion and primary operative dural repair.Extrinsic compression promote dural scarring by increasing surrounding tissue interstitial pressure(9).Symptomatic pseudomeningoceles can be effectively managed with continous lumbar drainage.
Weng etal(10) described open excision of pseudomeningocele to promote csf absorption into soft tissue along with primary dural closure.Primary dural closure is usually practically impossible because of dural dessication often needing patch closure. Large dural defects can be closed with patch techniques using autologous tissue, dural allografts, or fibrin glue along the suture line. Removal of pseudomeningoceles sac and the detethering of neural tissue is required if they adhere to duramater.
There are few reports of giant pseudomeningoceles(11, 12). Open surgery with excision of pseudomeningocele sac, repair of dural fistula , and prophylactic lumbar drainage is recommended. The combination method of treatment was found safe and effective(11, 12).
Cervical pseudomeningocele present a challenge since herniation of neural tissue produces catastrophic complications.So early surgical intervention is indicated.
Delayed infection of pseudomeningocele was reported by Koo et al(13).
CONCLUSION
Pseudomeningoceles after posterior fossa surgery pose a technical challenge to operating neurosurgeons . We present a rare case of delayed onset huge refractory multiloculated cervical psedomeningocele after retromastoid craniectomy which was succesfully repaired.Detailed review of literature regarding its mechanism of progression and a technical note of surgical repair is included.
REFERENCES
1. Hyndman OR, Gerber WF. Spinal extradural cysts, congenital and acquired; report of cases. Journal of neurosurgery. 1946;3(6):474-86.
2. Miller PR, Elder FW, Jr. Meningeal pseudocysts (meningocele spurius) following laminectomy. Report of ten cases. The Journal of bone and joint surgery American volume. 1968;50(2):268-76.
3. Hawk MW, Kim KD. Review of spinal pseudomeningoceles and cerebrospinal fluid fistulas. Neurosurgical focus. 2000;9(1):e5.
4. Akhaddar A, Boulahroud O, Boucetta M. Nerve root herniation into a calcified pseudomeningocele after lumbar laminectomy. The spine journal : official journal of the North American Spine Society. 2012;12(3):273.
5. Nairus JG, Richman JD, Douglas RA. Retroperitoneal pseudomeningocele complicated by meningitis following a lumbar burst fracture. A case report. Spine. 1996;21(9):1090-3.
6. Rinaldi I, Hodges TO. Iatrogenic lumbar meningocoele: report of three cases. Journal of neurology, neurosurgery, and psychiatry. 1970;33(4):484-92.
7. Couture D, Branch CL, Jr. Spinal pseudomeningoceles and cerebrospinal fluid fistulas. Neurosurgical focus. 2003;15(6):E6.
8. Rocca A, Turtas S, Pirisi A, Agnetti V. Iatrogenic lumbar pseudomeningocele. Zentralblatt fur Neurochirurgie. 1986;47(4):311-5.
9. Mehendale NH, Samy RN, Roland PS. Management of pseudomeningocele following neurotologic procedures. Otolaryngology–head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery. 2004;131(3):253-62.
10. Weng YJ, Cheng CC, Li YY, Huang TJ, Hsu RW. Management of giant pseudomeningoceles after spinal surgery. BMC musculoskeletal disorders. 2010;11:53.
11. Hader WJ, Fairholm D. Giant intraspinal pseudomeningoceles cause delayed neurological dysfunction after brachial plexus injury: report of three cases. Neurosurgery. 2000;46(5):1245-9.
12. Singh M, Kasliwal MK, Mahapatra AK. Giant cervical pseudomeningocoele following brachial plexus trauma. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia. 2008;15(3):310-3.
13. Koo J, Adamson R, Wagner FC, Jr., Hrdy DB. A new cause of chronic meningitis: infected lumbar pseudomeningocele. The American journal of medicine. 1989;86(1):103-4.
END NOTE
LIST OF ABBREVIATIONS
CSF- CEREBROSPINAL FLUID
CP ANGLE ‘CEREBELOPONTINE ANGLE
CT -COMPUTERISED TOMOGRAPHY
DECLARATION- This study has not received any financial support. Authors alone are responsible for the content of the paper. There are no conflicts of interest
Fig1: Preoperative contrast MRI showing 5??4cm cp angle lesiion
Fig2: Immediate post operative CT scan showing complete tumour removal with no evidence of pseudomenigocele
Fig3: Preoperative picture showing pseudomeningocele with healed intact wound.thick white arrow showing pseudomeningocele
Fig4: CT scan showing huge refractory pseudomeningocele
Fig5: Multiloculated pseudomeningocele(long white arrow) with the small defect(small white arrow)
Fig 6:Craniectomy site after excision of pseudomeningocele sac.Trying to suture the small defect primarily
Fig7: Small defect is enlarged after excising the fibrotic periphery of small defect
Fig8: The enlarged defect is closed using autologous dural substitute obtained from occipital fascia.
Fig9: Post operative CT scan after repair of dural leak and excision of pseudomeningocele sac.
Fig10: post operative picture showing no pseudomeningocele