Introduction:Impaired vascular perfusion in tissue expander (TE) breast reconstruction leads to mastectomy skin necrosis. We investigated factors and costs associated with skin necrosis in postmastectomy breast reconstruction.Methods:Retrospective review of 169 women with immediate TE placement following mastectomy between May 1, 2009 and May 31, 2013 was performed. Patient demographics, comorbidities, intraoperative, and postoperative outcomes were collected. Logistic regression analysis on individual variables was performed to determine the effects of tissue expander fill volume and mastectomy specimen weight on skin necrosis. Billing data was obtained to determine the financial burden associated with necrosis.Results:This study included 253 breast reconstructions with immediate TE placement from 169 women. Skin necrosis occurred in 20 flaps for 15 patients (8.9%). Patients with hypertension had 8 times higher odds of skin necrosis [odd ratio (OR), 8.10, P < 0.001]. Patients with TE intraoperative fill volumes >300 cm3 had 10 times higher odds of skin necrosis (OR, 10.66, P =0.010). Volumes >400 cm3 had 15 times higher odds of skin necrosis (OR, 15.56, P = 0.002). Mastectomy specimen weight was correlated with skin necrosis. Specimens >500 g had 10 times higher odds of necrosis and specimens >1000 g had 18 times higher odds of necrosis (OR, 10.03 and OR, 18.43; P =0.003 and P <0.001, respectively). Mastectomy skin necrosis was associated with a 50% increased inpatient charge.Conclusion:Mastectomy flap necrosis is associated with HTN, larger TE volumes and mastectomy specimen weights, resulting in increased inpatient charges. Conservative TE volumes should be considered for patients with hypertension and larger mastectomy specimens.

OBJECTIVEIntraoperative molecular imaging with tumor-targeted fluorescent dyes can enhance resection rates. In contrast to visible-light fluorophores (e.g., 5-aminolevulinic-acid), near-infrared (NIR) fluorophores have increased photon tissue penetration and less contamination from tissue autofluorescence. The second-window ICG (SWIG) technique relies on passive accumulation of indocyanine green (ICG) in neoplastic tissues. OTL38, conversely, targets folate receptor overexpression in nonfunctioning pituitary adenomas. In this study, we compare the properties of these 2 modalities for NIR imaging of pituitary adenomas to better understand the potential for NIR imaging in neurosurgery.METHODSA total of 39 patients with pituitary adenomas were enrolled between June 2015 and January 2018 in 2, sequential, IRB-approved studies. Sixteen patients received systemic ICG infusions 24 hours prior to surgery, and another 23 patients received OTL38 infusions 2–3 hours prior to surgery. NIR fluorescence signal-to-background ratio (SBR) was recorded during and after resection. Immunohistochemistry was performed on the 23 adenomas resected from patients who received OTL38 to assess expression of folate receptor–alpha (FRα).RESULTSAll 16 adenomas operated on after ICG administration demonstrated strong NIR fluorescence (mean SBR 4.1 ± 0.69 [SD]). There was no statistically significant difference between the 9 functioning and 7 nonfunctioning adenomas (p = 0.9). After administration of OTL38, the mean SBR was 1.7 ± 0.47 for functioning adenomas, 2.6 ± 0.91 for all nonfunctioning adenomas, and 3.2 ± 0.53 for the subset of FRα-overexpressing adenomas. Tissue identification with white light alone for all adenomas demonstrated 88% sensitivity and 90% specificity. SWIG demonstrated 100% sensitivity but only 29% specificity for both functioning and nonfunctioning adenomas. OTL38 was 75% sensitive and 100% specific for all nonfunctioning adenomas, but when assessment was limited to the 9 FRα-overexpressing adenomas, the sensitivity and specificity of OTL38 were both 100%.CONCLUSIONSIntraoperative imaging with NIR fluorophores demonstrates highly sensitive detection of pituitary adenomas. OTL38, a folate-receptor–targeted fluorophore, is highly specific for nonfunctioning adenomas but has no utility in functioning adenomas. SWIG, which relies on passive diffusion into neoplastic tissue, is applicable to both functioning and nonfunctioning pituitary adenomas, but it is less specific than targeted fluorophores. Thus, targeted and nontargeted NIR fluorophores play important, yet distinct, roles in intraoperative imaging. Selectively and intelligently using either agent has the potential to greatly improve resection rates and outcomes for patients with intracranial tumors.

In this preliminary study of a small set of patients, we demonstrate that second-window ICG can provide NIR optical tumor contrast in 3 types of ventral skull-base tumors. Chordomas demonstrated the weakest NIR signal, suggesting limited utility in those patients. Both nonfunctional and functional pituitary adenomas appear to accumulate ICG, but utility for margin detection for the adenomas is limited by low specificity. Craniopharyngiomas with third ventricular extension appear to be a particularly promising target given the clean brain parenchyma background and strong SBR.

This study directly demonstrates FRα overexpression in both human and canine meningiomas. We also demonstrate superb intraoperative imaging of a meningioma using a FRα-targeting dye.