Novel surgical technique to solidify cyst-type metastatic brain tumors using autologous fibrin glue for complete resection.

BACKGROUND: An outstanding issue regarding the surgical treatment of cyst-type metastatic brain tumors is the incomplete resection of cyst walls. Herein we propose a novel surgical technique that can overcome this issue. During a surgical procedure for cystic tumors, autologous fibrin glue is to be injected into the tumor cysts, which solidifies the cyst lumens and cyst walls en bloc with reducing the tumor size. As a result, tumor masses and cyst walls can be removed completely in an en bloc fashion in all cases.
METHODS: The illustrative case presented in this report is a patient with metastatic brain tumors in the frontal lobe. When we reached the tumor wall surgically, we first suctioned out the cyst content and subsequently injected autologous fibrin glue into the cyst lumen. The autologous fibrin glue solidified the tumor en bloc, and we resected the tumor mass and the cyst walls in an en bloc fashion.
RESULTS: We have applied this technique to four cases with cyst-type metastatic brain tumors. This approach made it possible to perform ideal en bloc resection in all cases. There were no adverse events due to the autologous fibrin glue.
CONCLUSION: We developed a novel surgical technique to solidify cyst-type metastatic brain tumors using autologous fibrin glue, which allows en bloc resection of tumor masses and cyst walls quite safely using inexpensive materials. Given these advantages, it appears a promising surgical strategy for cyst-type metastatic brain tumors.

INTRODUCTION

Among various therapeutic approaches for metastatic brain tumors, surgical resection is the most powerful because it allows a substantial reduction in tumor volume. In particular, en bloc resection of tumors is considered ideal (including those with a circumferential margin of about 5 mm).[3] However, cystic tumors are often difficult to completely remove due to the thinness and plasticity of the cyst walls. There is also a risk of tumor dissemination by dispersion of the cyst contents into cerebrospinal fluid.[4] To overcome these issues, several ingenious methods have been proposed to solidify the cystic tumors with solid-state materials such as cotton sheets or hydrofiber dressing.[5] To further strengthen the principle of these strategies, we developed another new technique to use liquid-state autologous fibrin glue for cyst-type metastatic brain tumors. In this technique, autologous fibrin glue fill cyst lumens and solidify the tumors en bloc. As a result, it became easily achievable to resect tumor masses/cyst walls en bloc in all cases. Given the advantages of this technique, it appears a promising surgical strategy for cyst-type metastatic brain tumors.

METHODS

Herein we show an illustrative case of metastatic brain tumor in bilateral frontal lobes [Figure 1a]. To apply this technique, we collected 300 ml of peripheral blood from the patient in advance and extracted approximately 6 ml of autologous cryoprecipitate. At the beginning of the surgery, 5000 units thrombin (Mochida, Tokyo, Japan) was dissolved in physiological saline in total 7.5 ml. Then, we performed a bilateral craniotomy to approach the large cystic lesion in the right frontal lobe. When we reached the tumor located in the right frontal lobe, the cyst contents were suctioned out to investigate the inside of the tumor cyst [Figure 2a]. A small piece of the tumor tissue was removed for intraoperative pathological diagnosis, and the autologous cryoprecipitate (6 ml) and the thrombin solution (6 ml) were injected into the cyst lumen [Figure 2b]. Intraoperative ultrasonography pre- and postinjection of the fibrin glue demonstrated a substantial reduction in tumor size (less than half in diameter) along with the solidification of the cyst walls [Figure 3]. We resected the tumor mass and the cyst walls in an en bloc fashion [Figure 2c–f]. Postoperative magnetic resonance images demonstrated complete resection with no remnants [Figure 1b]. No particular adverse events were encountered during the perioperative period.

Figure 1

MR images before and after surgery. (a) Preoperative images. The tumors are located in the bilateral frontal lobes; the present method is planned for the right frontal lesion. (b) Postoperative images 1 day after surgery. Total resection of the tumor is achieved with no tumor remnants. Both are coronal contrast-enhanced T1-weighted images

Figure 2

Intraoperative photographs. (a) Cyst contents are drained and the lumen is observed. (b) Autologous cryoprecipitate and thrombin solution are injected simultaneously. (c) Tumor cyst is solidified. The autologous fibrin glue is filled to level of the injection site. (d) En bloc resection is performed including the cyst walls. (e) Resected tumor. Arrow: the injection site. (f) Separation of the solidified autologous fibrin glue from the cystic tumor

Figure 3

Intraoperative ultrasound photographs. (a) Before drainage of the cyst contents. (b) After the drainage of cyst contents followed by injection of autologous fibrin glue. The tumor size reduces to less than half of the original size. The cyst wall is thickened

RESULTS

We have applied this technique to four cases with cyst-type metastatic brain tumors. This approach made it possible to perform ideal en bloc resection in all cases. There were no adverse events, local recurrence, and/or dissemination observed during 3 months follow-up periods.

DISCUSSION

Autologous fibrin glue was first reported in 1983 and is currently used in various surgical procedures.[1] Autologous fibrin glue offers excellent tissue hemostasis, adhesion, and covering effects. In addition, complement and immunoglobulins in autologous fibrin glue are known to inhibit proliferation of Escherichia coli, which suggests that this material can help prevent surgical wound infection.[2]

We used the autologous fibrin glue to solidify tumor cyst lumens and cyst wall en bloc. This method allows complete resection of tumor masses and cyst walls in most cases. Previously, cotton sheets, hydrofiber dressing, or some other solid-state materials have been used to solidify the cystic tumors.[5] In this study, to further strengthen the principle of these strategies, we developed another new technique to use liquid-state autologous fibrin glue for cyst-type metastatic brain tumors. Compared with the solid-state materials, the autologous fibrin glue can fill the cyst lumens equally even if tumors are in complex shapes. Moreover, autologous fibrin glue solidifies the cystic tumors to a moderate hardness (harder than normal tissues), which makes cyst wall resection very feasible. Another advantage of the present method is that solidification of the cyst contents can prevent tumor cell dissemination into cerebrospinal fluid. Furthermore, the present method reduces the tumor size approximately into half, which makes the resection much easier. Finally, autologous fibrin glue is relatively inexpensive to prepare compared with commercially available fibrin glue products and therefore can be used easily at most institutions.

We have not achieved long-term follow-up for the patients thus far. However, mid-term follow-up (3 months at shortest) indicates no local recurrence or dissemination. However, it still remains to be elucidated whether this technique contributes to reduce local failure and/or dissemination during long-term follow-up periods after surgery.

A disadvantage of the present method is that autologous blood draw is necessary prior to surgery. Since advanced cancer patients often exhibit chronic anemia, even a small volume of blood draw (200 ml) could be a heavy burden. Another possible issue is that viral infection or allergic reactions may occur because thrombin is derived from pooled human serum. To overcome this issue, complete thrombin isolation and purification system is currently under development.[6]

CONCLUSION

We developed a novel surgical technique to solidify cyst-type metastatic brain tumors using autologous fibrin glue. This procedure allowed en bloc resection of tumor masses as well as cyst walls in all cases quite safely using inexpensive materials. Given these advantages, it appears a promising surgical strategy for cyst-type metastatic brain tumors.

Author contributions to the study and manuscript preparation include the following: Conception and design: Okuda. Acquisition of data: All authors. Drafting the article: Okuda, Fujita. Study supervision: Kato.