Reconstruction of the Lacrimal Excretory System in the Medial Canthal Region.

The resection of malignant tumors in medial canthal region may lead to full-thickness defects including medial canthal ligament and lacrimal duct. There had been reports on various reconstructive methods, but none of those methods succeeded in lacrimal reconstruction with functional lacrimal excretory system. We experienced a case of conjunctival malignant melanoma at the lacrimal caruncle and performed new method of the reconstruction for full-thickness defects of the medial canthal region with the maintenance of the lacrimal drainage function.

CASE DESCRIPTION

A 72-year-old man had been aware of a black spot at the left lacrimal caruncle for 3 years. It gradually enlarged and protruded externally even with the eyes closed within 2 years. It was left untreated, but due to rapid enlargement of the tumor, the patient consulted an ophthalmologist.[1] Histopathological diagnosis was conjunctival malignant melanoma with a Breslow’s tumor thickness of 3 mm. No metastases were found in gallium scintigraphy and computed tomography examination. The patient was referred to our department for surgical treatment.

The operation was performed under general anesthesia. The sentinel lymph node biopsy along with the rapid pathological examination was performed. Because there was no lymph node metastasis, the lymph node dissection was not performed. The lacrimal caruncle and the adjacent conjunctiva 4 mm away from the tumor, including the cicatricial region, were resected, and cryotherapy was performed in the remaining region. The full layers of the upper and lower eyelids were resected.

The medial canthal portion was reconstructed with a median forehead flap. This flap was elevated beneath periosteum and was split in the mid-portion for the upper and lower eyelid. The split frontal muscle was adhered to the remnant orbicularis oculi muscle and medial canthal ligament with mattress sutures. The mucoepithelization was expected over the periosteum adhered to the remnant conjunctiva. We inserted the lacrimal duct reconstructed with the intraoral mucous membrane in between the layers of the frontal muscle of median forehead flap. A silicon stent was placed into the reconstructed duct for 3 months (Fig. 1, 2).

Fig. 1.

Intraoperative findings. The entire layers of skin of the upper and lower eyelids were resected including lacrimal apparatus. The medial canthal portion was reconstructed with a median forehead flap. We inserted the lacrimal duct reconstructed with the intraoral mucous membrane in the layers of the frontal muscle of median forehead flap.

Fig. 2.

Schema of procedure.

No epiphora had been observed after 4 years postoperatively. Lacrimal passage was patent by performing the patency test with natural saline. The result of the Schimer test was 3 mm on the right and 15 mm on the left, which indicated no symptoms of dry eye. Additionally, we performed Johns I test[2] and the fluorescein dye disappearance test (FDD test)[3] for the evaluation of the lacrimal drainage function. On both sides, the Jones I test for lacrimal drainage function was positive, and the FDD test was also positive after 2 minutes and 5 minutes. We evaluated that the lacrimal drainage function was maintained. Neither recurrence, distant metastasis nor epiphora has been observed for 10 years after the operation (Fig. 3).

Fig. 3.

Postoperative appearance. The satisfying morphology of the upper and lower eyelids was achieved. Both the superior and inferior reconstructed punctums have been maintained and no epiphora has been observed for 10 years after the operation.

DISCUSSION

The essential elements for lacrimal excretion are (1) gravity; (2) capillarity; (3) lacrimal pump function linked with eyelid movement,[4,5] but previously reported methods only included (1) and (2). Therefore, we established a reconstructive method with a functional lacrimal drainage system, which focused on (3). During the reconstruction of lacrimal pump function linked with eyelid movement, it is important to understand detailed anatomy of medial canthal region. Necessary components in medial canthal region are orbicularis oculi muscle, medial canthal ligaments, Horner muscle, lacrimal duct, and lacrimal sac. Necessary anatomical understanding areis: (1) medial canthal ligaments include tendon tissues from orbicularis oculi muscle pretarsal part in the surface layer, and muscle fiber from orbicularis oculi muscle pretarsal part transforms to tendon tissue underneath the surface layer, and (2) lacrimal duct/sac are surrounded by orbicularis oculi muscle, medial canthal ligament, Horner muscle, and generate pump system linked with eye movement.[6] Thus, to reconstruct lacrimal pump system linked with eye movement, reconstruction based on the ideas of anatomical studies mentioned above must to be performed (Fig. 4). By including periosteum and frontalis muscle in the median forehead flap to regenerate the linkage of the remaining orbicularis oculi muscle, we created an orbicularis oculi muscle sling. By positioning lacrimal duct to be surrounded by reconstructed orbicularis oculi muscle, the functional pump system along with the eye movement became possible. This method is considered to be aesthetically and functionally effective for full-thickness defects of the medial canthal region after the resections such as malignant tumors.

Fig. 4.

Mechanism of our reconstruction of the lacrimal excretory system. By positioning lacrimal duct to be surrounded by reconstructed orbicularis oculi muscle, the functional pump system along with the eye movement became possible.

SUMMARY

The resection of malignant tumors in medial canthal region may lead to full-thickness defects including medial canthal ligament and lacrimal duct, lacrimal reconstruction with functional lacrimal excretory system is difficult. The patient described in the following report was treated for a conjunctival malignant melanoma located at the left lacrimal caruncle. After wide local excision, the medial canthal portion was reconstructed with a median forehead flap. We inserted the lacrimal duct reconstructed with the intraoral mucous membrane in the layers of the frontal muscle of median forehead flap. JohnsItest and the FDD test showed that the reconstruction of the lacrimal drainage function was achieved successfully. This procedure provides both the lacrimal excretory function and the satisfying configuration of the medial canthal region.