Table 1: Synopsis of previously published clinical series including the number of their patients, the underlying pathologies, the employed surgical approach, and the outcome and complication rates.

Authors yearPts. numberPathologySurgical approachOutcomeMorbidity
Mortality Complications

Krieger et al. [27], 199931CM-I, CM-I + hydro-syringomyeliaOccipital craniectomy, C1 posterior arch removal, and duraplasty88% improvement in pts. with syrinx
3 patients required also a shunt
26% headaches
16% nausea
No mortality

Zérah [28], 1999188CM-I + hydro-syringomyeliaPosterior fossa decompression95% improvement/ stabilization of symptomsN/A

Lazarref and Valencia-Mayoral [29], 1990N/ACM-I + hydro-syringomyeliaPFD + cervical laminectomy if the ventricular shunt is patent88% symptom remissionN/A

Yundt et al. [30], 19963CM-IOccipital craniectomy, C1 posterior arch removal, and duraplasty100% improvementN/A

Isu et al. [31], 19937CM-I + hydro-syringomyeliaOccipital craniectomy and duraplasty6/7 improvement, 5/7 immediate syrinx decreaseN/A

Genitori et al. [32], 200053CM-I, CM-I + hydro-syringomyeliaOccipital craniectomy, C1 posterior arch removal, and duraplasty100% improvement in brainstem compression, 94.4% syringomyelia improvement, 97.2% overall improvement2/34 pts. required second surgery.
No mortality

Alden et al. [33], 200121CM-I, CM-I + hydro-syringomyeliasuboccipital craniectomy + cervical laminectomy in all pts
(i) durotomy + duraplasty: 4
(ii) resection of cerebellar tonsils + lysis of abhesions + duraplasty: 17
67% symptom resolution, 29% improvement, 4% no improvementN/A

Parker et al. [34], 2011114CM-IOccipital craniectomy, C1 posterior arch removal, and duraplasty with or without tissue sealant (15 cadaveric pericardium-12 Durepair-87 endura)N/AGraft-type and Cx rates: 26,7% cadaveric pericardium: 26.7% durepair: 41.7 % endura: 17.2%
Reoperation rates: cadaveric pericardium: 13% durepair: 25% endura: 8.1% Complications rates for tissue sealants: no sealant: 14,8% tisseel: 18,7% duraseal: 50%
Combined complication rate for durepair and DuraSeal: 56%
Cumulative Cx rate: 21.1%

Mottolese et al. [8], 201182CM-I, CM-I + hydro-syringomyelia, kyphosis/scoliosis(i) Occipital craniectomy, C1 posterior arch removal, and duraplasty (Group a: 43 pts)
(ii) Occipital craniectomy, C1 posterior arch removal, and duraplasty with Gore-Tex dural patch (Group b: 39 pts)
Group a: 70% improvement
Group b: 89% improvement
Group a: 18% complication rate Group b: 20,5% complication rate.
No mortality

Valentini et al. [35], 201199CM-I, CM-I + craniosynostosis, CM-I + hydrosyringomyeliaCraniovertebral decompression (Group a: 7 pts), craniovertebral decompression with duraplasty combined with tonsillar coagulation (Group b: 44 pts)91.5% syrinx decrease, 78% overall symptom improvementNo mortality
14% reoperation for CSF leakage, 6.8% oculomotor n. dysfunction, 2.8% venous thrombosis

Sindou et al. [36], 200244CM-I, CM-I + hydro-syringomyeliaCraniocervical decompression + far lateral foramen magnum opening + duraplasty with arachnoid preservation.Improvement based on KPS, improvement of syrinx in 60%, stabilization of syrinx in 40%4.5% CSF leakage,
2.3% laryngeal edema,
2.3% pneumonia, 11.4% wound infections
No mortality

Hoffman et al. [37], 198747CM-I,
acquired CM-I
31 pts posterior fossa decompression and plugging of the obex, 5 pts posterior fossa decompression, 9 pts shunting, 2 pts decompression with shunting70% improvement in pts undergoing obex pluggingNo mortality

Hida et al. [38], 199570CM-I, CM-I + hydro-syringomyelia33 pts foramen magnum decompression (Group a), 37 pts shunting (Group b)Group a: 94% reduced size of syrinx, 82% improvement
Group b: 100% syrinx reduction, 97% improvement
N/A

Eule et al. [39], 200225CM-I, CM-I + Kyphosis/ScoliosisDecompression with or without shuntEarly decompression resulted in improvement or stabilization of scoliosis in 5 casesN/A

Payner et al. [40], 199410Acquired CM-I2 pts conversion to ventriculoperitoneal shunt, 2 pts posterior fossa decompression100% symptom improvementN/A