The Diagnostic Utility of Splenectomy in Idiopathic Splenomegaly.

INTRODUCTION: With increasing frequency, patients with idiopathic splenomegaly are referred to surgeons for splenectomy. We evaluated the diagnostic utility of splenectomy and feasibility of a minimally invasive approach in the face of idiopathic splenomegaly. METHODS: We retrospectively reviewed 68 patients who underwent splenectomy for idiopathic splenomegaly. The primary endpoint was the rate of definitive diagnosis based on final surgical pathology of the removed spleen. RESULTS: Preoperative workup included a bone marrow biopsy and peripheral blood smear in 93% and 100% of patients, respectively, with none having lymphadenopathy warranting biopsy. Splenectomy provided a definitive diagnosis for 44 (64.7%) patients. Of these, 34 (50%) patients had an underlying malignancy, of which more than half were splenic marginal zone lymphoma. There were 33 (48.5%) laparoscopic, 23 (33.8%) open, 10 (14.7%) laparoscopic converted to open, and two (2.9%) laparoscopic hand-assist cases. Conversion to open was due to splenic size [median craniocaudal length 21.8 cm (cm)] in eight and staple line bleeding at the splenic hilum in two patients. Overall, the laparoscopic approach was completed in patients with a smaller splenic size compared to open (median craniocaudal length 15.2 vs. 26.0 cm, p < 0.0001). The open group had one (1.5%) intra-operative mortality due to uncontrollable hemorrhage. Thirty-day complication rates were similar for laparoscopic and open approaches (p = 0.10). CONCLUSION: Splenectomy is an effective diagnostic modality in determining a pathologic cause for splenomegaly in this patient population. Laparoscopic splenectomy can be performed safely in appropriate cases with craniocaudal splenic size having the largest influence on surgical approach.

Adult males buffer the cortisol response of young guinea pigs: Changes with age, mediation by behavior, and comparison with prefrontal activity.

In the guinea pig, the presence of the mother buffers hypothalamic-pituitary-adrenal (HPA) responses of her young during exposure to a novel environment, and can do so even if she is anesthetized. In contrast, under comparable conditions other conspecifics (siblings, other adult females) are less effective or ineffective in doing so. However, we recently observed that an unfamiliar adult male reduced plasma cortisol elevations and increased Fos in the prefrontal cortex of preweaning pups exposed to a novel enclosure for 120min. Here we found adult males buffered the adrenocortical response of preweaning pups at 60 as well as 120min and of periadolescent guinea pigs if exposure was of 120min. Further, because males vigorously engaged in social interactions with the young during exposure, we examined the effect of behavior by comparing the impact of conscious and unconscious (anesthetized) adult males. When tested with a conscious but not unconscious male, pups exhibited reduced plasma cortisol elevations. Pups, particularly females, had greater Fos induction in the prefrontal cortex when with a conscious versus unconscious adult male. Overall, we found that an unfamiliar adult male can buffer the cortisol response of guinea pigs both before and after weaning, though more-prolonged exposure appears necessary in the older animals. Further, unlike buffering by the biological mother, the effect of the male is mediated by behavioral interactions. Thus, the buffering of the infant guinea pig's cortisol response by the mother and an unfamiliar adult male involve different underlying mechanisms.