Laparoscopic partial pancreatectomy through an advanced lateral approach as treatment for insulinoma in dogs: a case series

Abstract

A minimally invasive partial pancreatectomy was performed through a novel laparoscopic lateral flank approach in sternal-oblique recumbency in four clinical cases presented with an insulinoma. All four cases were female castrated dogs of older age (range 7-9 years) and different breeds (Wire haired dachshund, German shepherd, Jack Russel terrier, and Boxer), and all presented with episodic weakness, tremors, and/or seizures. The diagnosis was based on plasma glucose level below reference range with concomitant increased or normal insulin level. A laparoscopic approach was considered based on triple-phase contrast-enhanced computed tomography findings of the abdomen, revealing a pancreatic mass situated in the right pancreatic limb or left pancreatic limb without suspicion of metastasis. Laparoscopic procedures were performed without any major complications, and peri-operative glycemia increased to (supra-)normal levels in all cases. Histopathologic reports qualified the masses as neuroendocrine carcinomas, and in conjunction with the clinical picture, this neoplasia was further defined as insulinoma. Post-operative care in an intensive care unit was of short duration, and all animals were discharged being clinically normal and normoglycemic in between 1.5 and 2.5-day post-surgery. At short-term follow-up, no dogs showed clinical abnormalities, all recovered well from the surgical procedure, and blood glucose levels remained in the normal range. During long-term follow-up, 2 cases remained clinically normal at the time of writing, 564 and 1,211 days after surgery, 1 dog had recurrence of hypoglycemic episodes after 246 days and was euthanized after 673 days of surgery due to progressing disease, and 1 dog was euthanized after 1,028 days of surgery due to reasons unrelated to the insulinoma. Survival times ranged from 599 to 1,232 days after diagnosis. Considering the highly metastatic nature and difficulty of full laparoscopic staging of insulinoma patients, thorough pre-operative disease staging is warranted when considering a laparoscopic approach. This case series shows the feasibility of a novel laparoscopic flank approach for right and left partial pancreatectomy in dogs. Furthermore, proper case selection resulted in favorable outcome in these insulinoma patients.

Keywords: abdominal surgery; canine; companion animals; endocrine; minimally invasive; neoplasia; neuroendocrine; pancreas.

Figure 1

Patient positioned in sternal recumbency and portal placement for a (left) laparoscopic flank approach. Positioning of the patient in sternal, slightly right lateral oblique recumbency with elevation of thorax and pelvis. The initial camera portal is placed 1–3 cm caudal of the last rib and 3–5 cm ventral of the vertebral transverse processes. The location of two additional portals for a triangulated surgical approach depends on the intraoperative situation.

Figure 2

Surgical view and anatomic references directly after abdominal entry through a right (A) and left (B) lateral laparoscopic approach in sternal recumbency. A: adrenal gland; D: duodenum; K: kidney; L: liver; P: pancreas; S: spleen; T: tumor.

Figure 3

Laparoscopic image of the insulinoma situated in the affected pancreatic lobe during pancreatectomy in sternal recumbency in each patient. (A): Case 1, right flank approach, mid right lobe; (B): case 2, left flank approach, mid left lobe; (C): case 3, left flank approach, distal left lobe; (D): case 4, left flank approach, proximal left lobe. A: adrenal gland; D: duodenum; I: ileum; K: kidney; L: liver; P: pancreas; S: spleen; SV: splenic vein; T: tumor.