Y-shaped shunt for the treatment of Dandy-Walker malformation combined with giant arachnoid cysts:A case report

lNTRODUCTlON

Dandy-Walker malformation(DWM)was first reported by Dandy and Blackfan[1]in 1914.It is a rare congenital malformation characterized by partial or complete dysplasia of the cerebellar vermis,cystic dilation of the four ventricles,upward displacement of the tentorium,increased anteroposterior diameter of the posterior fossa,and connection between the posterior fossa cysts with the four ventricles in most cases[2].According to the latest epidemiological survey in Europe,the incidence rates of DWM are 6.79/100000 and 2.74/100000 in infants and live births,respectively[3].The diagnosis of DWM mainly relies on imaging.The magnetic resonance imaging(MRI)manifestations of DWM are:(1)Presence of giant arachnoid cysts in the posterior fossa that communicate with the fourth ventricle,with elevated tentorium cerebelli and torcular herophili due to pressure;(2)Developmental abnormality or deficiency of cerebellar vermis,which might be accompanied by cerebellar hemisphere dysplasia and forward displacement of the brain stem due to pressure;(3)Significant dilation of the three ventricles and the lateral ventricles,as well as hypoplasia of the corpus callosum;and(4)Hydrocephalus in about 70%-90% of patients[4].Differential diagnosis included:(1)Giant arachnoid cysts in the posterior fossa,which manifest as cysts of cerebrospinal fluid density,but are not connected with the fourth ventricle.The cysts might be separated by trabeculae,and the fourth ventricle remained normal.The cerebellar vermis appeared normal,but was shifted;and(2)Enlarged cisterna magna,in which cysts are present in different sizes,normally ranging from 2-6 cm.The cerebellar vermis,cerebellar hemisphere and the fourth ventricle appeared normal,with no occupying effect,no hydrocephalus,and normal size of the posterior fossa.In this case report,typical characteristics of DWM were found,and were accompanied by giant and isolated arachnoid cysts in the posterior fossa,warranting different preoperative evaluation and intraoperative treatment.

8. Threw him with all her might against the wall: The earliest versions of the story have the princess committing an act of violence which breaks the spell instead of the now famous kiss. Most often the frog is thrown against the wall, but in some versions he is beheaded or his skin is burnt. Sometimes, simply sleeping in the princess bed is sufficient to break the spell. Maria Tatar notes that passion rather than compassion34 leads to a happy ending to this tale (Tatar 1988).

CASE PRESENTATlON

Chief complaints

Family members complained that the child could not walk steadily for 2 mo.

History of present illness

The family members reported that the child was admitted to a local hospital due to fever,diarrhea and vomiting 2 mo ago,and was diagnosed with a cold.He was administered intramuscular injections of antibiotics for 5 d(specific drugs unknown),and showed improvement in his condition.However,staggering occurred again,and the boy was unable to sit or stand.The family members brought him to our hospital for further care,and the patient was admitted in the inpatient department of our Pediatric Neurology Department.

Physical examination

Physical examination at the time of admission revealed increased head circumference(52 cm),closed anterior fontanelle,unstable standing,staggering,and ataxic gait.

Laboratory examinations

Blood routine examination showed that leukocyte elevation.Urine routine,fecal routine and occult blood examination,blood biochemistry,immune indexes and infection indexes were normal.

Imaging examinations

Brain computed tomography(CT)and MRI revealed significantly dilated supratentorial ventricles,capped edema at bilateral frontal angles,huge occupying cysts in the right cerebellar hemisphere,and compression displacement in the right cerebellar hemisphere and the four ventricles(Figure 1).

The patient underwent a combined shunt for supratentorial hydrocephalus and infratentorial giant solitary arachnoid cysts.

The patient was a 20 mo old boy,initial diagnosis revealed DWM with giant isolated arachnoid cysts in the posterior fossa.After admission,the patient underwent stereotaxic aspiration for arachnoid cysts in the posterior fossa,confirming that the cystic fluid was cerebrospinal fluid and excluding malignant lesions.After stereotaxic aspiration,the cysts were significantly shrunk,but the supratentorial hydrocephalus showed no improvement.It was speculated that aqueduct obstruction due to adhesion rather than compression would result in occlusion between the supratentorial and subtentorial parts;meanwhile,unobstructed aqueduct and blocked fourth ventricle outlet would result in obstructive hydrocephalus between the supratentorial and subarachnoid spaces.Neither a cysto-peritoneal shunt(C-P shunt)nor a ventriculoperitoneal shunt(V-P shunt)alone solved the hydrocephalus at the same time,and the patient underwent a combination of supratentorial-infratentorial shunt placement for the hydrocephalus and isolated cysts.Preoperative cystic fluid analysis confirmed that the cystic fluid was clear,and the typical arachnoid cysts included proteins at 0.32(reference:0.24-0.44 g/L),glucose at 2.9(reference:2.4-4.4 mmol/L),and chlorine at 116.1(reference:119.0-129.0 mmol/L).They were colorless and transparent,with negative Pandy’s test and white blood cell at 4.0(reference:0.00-8.00 × 10/L).

A few days after the crash, Sonali s brother Chris, concerned that Sonali might not understand what was really happening, asked her, Do you know where Daddy is?

For the surgical procedure,the occipital puncture point was located 5 cm above the external occipital protuberance and 2.5 cm lateral to the midline.A U-shaped incision was made on the scalp(Figure 2A and C).Then,a bone hole of 3-mm diameter was made using a bone drill,which was 10 cm in depth and directed 2 cm above the midpoint of the ipsilateral superciliary arch.Afterwards,a longitudinal incision was made at the posterosuperior part of the ear,and a supratentorial adjustable pump(Medtronic,StrataII Shunt Assembly,Regular,with BioGlide;pressure,80 cmHO)was placed behind the ear,connected to a three-way valve(Medtronic Catheter Connector,3-Way)(Figure 2D).A subtentorial puncture was performed at 5 cm lateral to the midline and 2 cm below the transverse sinus.A U-shaped incision was made on the scalp(Figure 2A and C),and a 3-mm diameter bone hole was made using a bone drill,which was 3 cm in depth and directed to the vertical bone plate.A drainage tube was connected to the ordinary non-adjustable pump(Medtronic,Deltashunt Kit,Regular,Performance Level 1.5),and further connected to the three-way valve.The other end of the three-way valve was connected to the end of the abdominal cavity,as in general shunt therapy(Figure 2B).

hydrocephalus and the subtentorial arachnoid cyst induced by Dandy-Walker malformation.The patient had no complications,such as fever,subdural effusion and hematoma after operation,and recovered well.Therefore,the abovementioned procedure has a positive effect on the prognosis of patient.The patient was followed-up for 2 years,and could walk independently;the high intracranial pressure had disappeared,and the boy was feeding normally.Nonetheless,the efficacy of the surgery is subjected to long-term follow-up.To the best of our knowledge,this is the first case report of DWM with giant isolated arachnoid cysts in the posterior fossa,which was treated with a combination of supratentorial and subtentorial cyst shunts.

FlNAL DlAGNOSlS

Initial diagnosis revealed DWM with giant isolated arachnoid cysts in the posterior fossa.

TREATMENT

The needle had barely put in its last stitch when the girl, glancing at the window, spied the white plumed19 hat of the King s son who was being led back by the spindle with the golden thread

OUTCOME AND FOLLOW-UP

The patient had no complications,such as fever,subdural effusion and hematoma after operation,and recovered well.The patient was followed-up for 2 years,and could walk independently;high intracranial pressure had disappeared and he was feeding normally.

British Intelligence heard of her arrest. The BBC broadcast the news that the Nazi had put Germany s beloved singer into a concentration camp. This British intervention27 may have helped save her. The Gestapo seemed to lose interest in her, and she slipped away quietly to her grandparents home on a North Sea island, staying there until the war ended.

DlSCUSSlON

About 20% of patients with DWM had no clinical symptoms and require no treatment.Experts around the world continue to debate regarding the treatment of patients with DWM and hydrocephalus.Mohanty[5]retrospectively analyzed the surgical methods utilized in 72 children with DWM.The initial surgical treatments included V-P shunt placement in 21 patients,C-P shunt placement in 24,and combined V-P and C-P shunt insertion in 3.Twenty-one patients underwent endoscopic procedures and 3 cases underwent membrane excisiona posterior fossa craniectomy.The authors believed that neuroendoscopy is a good surgical method for DWM.Mohanty[5]pointed out hernia above posterior fossa cysts as a potential complication of V-P shunting alone,which rapidly deteriorates the clinical symptoms.In addition,C-P shunting alone is associated with a risk of chronic inferior herniation of the cerebral hemisphere through tentorial notch or causes tethering of the brain stem[6-8].Kumar[9]compared different treatment methods and outcomes in 42 patients,and proposed V-P shunting should be followed by C-P shunting as posterior fossa cysts did not disappear or the symptoms recurred after V-P shunt placement.Meanwhile,if C-P shunting alone is implemented,this should be followed by V-P shunt placement as well due to continuous dilation of lateral ventricles.Hence,lateral ventricle and cyst shunting was performed to decompress the posterior fossa cysts and lateral ventricle simultaneously,thereby achieving the purpose of clinical cure.Generally,cyst fenestration is suitable for patients without hydrocephalus.

Written informed consent was obtained from the patient’s guardian.

CONCLUSlON

The child in the current case report suffered from cerebellar vermis dysphasia,accompanied by giant isolated arachnoid cysts in the posterior fossa,with the arachnoid cysts not connected to the occipital cistern.The supratentorial ventricle was enlarged,and there was an obvious capped edema at the bilateral frontal angle.Regardless of aqueduct obstruction status,the supratentorial or ventriculoperitoneal shunt alone did not solve the problem of arachnoid cysts that compressed the cerebellum as well as the brain stem.After sufficient preoperative evaluation,the patient received a ventriculoperitoneal shunt(adjustable anti-siphonic diverter pump)combined with a arachnoid cyst(medium pressure nonadjustable diverter pump)-peritoneal shunt,during which the Y-shaped three-way valve was finally used to simultaneously solve the problem of different pressures between the supratentorial

After the surgery,the child had no significant complications,and showed improvement with regarding to the symptoms of staggering and high intracranial pressure.On the third day after operation,he could walk independently.Postoperative CT showed significant improvement of supratentorial hydrocephalus and shrunk cysts in the posterior fossa,and the compressed cerebellar hemisphere was restored(Figure 3A).In addition,the incision healed well postoperatively,and the child’s mental state was improved significantly(Figure 3B).The child was depressed before operation.

FOOTNOTES

Dong ZQ conceived and coordinated the study,designed,performed and analyzed the experiments,and wrote the paper;Jia YF,Gao ZS,Li Q,Niu L,Yang Q,Pan YW and Li Q carried out data collection and analysis,and revised the paper;all authors reviewed the results and approved the final version of the manuscript.

People ask me about tips. As far as I know, practically everyone will give you something. Come to think of it, most Americans are pretty generous. I always try to be nice to everyone, whether they tip or not. I believe in God and try to be a good member of my parish. I try to act toward others like I think God wants me to act. I have been trying this for a long time, and the longer I try, the easier it gets.

And the floor creaked, and the ceiling was all made of glass mirrors, so that he saw himself standing on his head, and by each window were standing three reporters and an editor; and each of them was writing down what was said, to publish it in the paper that came out and was sold at the street corners for a penny

Well, said her godmother, be but a good girl,28 and I will contrive21 that thou shalt go. Then she took her into her chamber, and said to her, Run into the garden, and bring me a pumpkin22. 29

The authors declare that they have no conflict of interest.

The authors have read the CARE Checklist(2016),and the manuscript was prepared and revised according to the CARE Checklist(2016).

This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers.It is distributed in accordance with the Creative Commons Attribution NonCommercial(CC BYNC 4.0)license,which permits others to distribute,remix,adapt,build upon this work non-commercially,and license their derivative works on different terms,provided the original work is properly cited and the use is noncommercial.See:https://creativecommons.org/Licenses/by-nc/4.0/

China

Zhi-Qiang Dong 0000-0001-9353-5896;Yan-Fei Jia 0000-0003-0476-9987;Zhen-Shan Gao 0000-0003-0039-9608;Qiao Li 0000-0002-9455-4180;Liang Niu 0000-0002-5266-2909;Qiang Yang 0000-0003-0226-992X;Ya-Wen Pan 0000-0002-2247-8027;Qiang Li 0000-0001-9815-2229.

Yan JP

A

Yan JP