Deep Margins Melanoma: How Deep Is Deep Enough?

BACKGROUND: Wide excision (WE) to muscular fascia for invasive melanoma is common practice but excision to subcutaneous tissue may be adequate. We evaluated practice patterns regarding depth of biopsy and excision as well as risks for recurrence. METHODS: Retrospective review of patients with pT1-4 melanoma (cN0) treated with WE at a single institution was performed. Patient factors were evaluated. Biopsy and excision techniques were compared to pathology and reviewed for recurrence. RESULTS: 385 patients from 2006 to 2020 were included. Lesions were on the extremity (n = 189), head/neck (n = 48), trunk (n = 148). Biopsy techniques included shave (n = 330), excisional (n = 36), punch (n = 10), incisional (n = 9). Deep biopsy margins were positive for IM/melanoma in situ in 139 patients. WE specimens were taken to muscular fascia (n = 218) or mid/deep fat (n = 144). 51 patients had recurrent disease or a new primary lesion: locoregional (n = 31), distant (3), or new lesions (n = 17). DISCUSSION: Patient characteristics associated with recurrence include older age and female gender. Tumor characteristics associated with recurrence include lesions located on the trunk, superficial spreading melanoma, ulceration, perineural invasion, and clinical T and P stage. Patients that recurred were more likely to have WE taken to or including muscular fascia. Biopsy type, deep margin on biopsy, and depth of dissection was not associated with recurrence.

Etiology of iliocaval stent thrombosis.

OBJECTIVE: Although correction of iliac vein stenosis is safe and efficacious, one of its major complications is iliac vein stent thrombosis. In an attempt to examine the cause of iliac vein stent thrombosis, we reviewed the location of underlying lesions encountered after thrombectomy or thrombolysis of iliac vein stents. METHODS: A retrospective analysis was performed of all iliac vein venograms with intravascular ultrasound examinations at our office-based surgical center from February 2012 to July 2016. Patients included in the study had chronic venous insufficiency and failed compression therapy. All procedures were performed with local anesthesia and conscious sedation. Wallstents were used in all procedures for nonthrombotic iliac vein stenosis, ranging from 8 to 24 mm in diameter and 40 to 90 mm in length. Patients were followed with transcutaneous duplex every 3 months for the first year and every 6 to 12 months thereafter. Patients were placed on clopidogrel for 3 months or continued on their preexisting anticoagulants. RESULTS: From February 2012 to July 2016, we performed 2228 iliac vein venograms with intravascular ultrasound examination in 1381 patients. The mean age of the patient population was 65 ±14 years (range, 21-99 years), among which 876 were female. A total of 1037 procedures were performed in the left lower extremity. Of these, 240 venograms were diagnostic. Presenting symptoms based on CEAP classification included C2 (n = 21), C3 (n = 633), C4 (n = 1065), C5 (n = 269), and C6 (n = 241). Complete thrombosis of the iliac vein stent was noted in 18 patients (0.8%) who thereafter underwent suction thrombectomy with thrombolysis. None of these patients had a prior history of deep vein thrombosis. In-stent restenosis was noted in 11 patients. Proximal lesions were found in no patients. An external iliac vein lesion was found distal to the common iliac vein stent in two patients. Common femoral vein lesions were found in six patients. These encountered lesions were then stented. All patients who underwent thrombectomy were placed on anticoagulation for 6 months. No patient were noted to suffer rethrombosis upon follow-up. No correlation with stent thrombosis was encountered for age, gender, laterality, location, presenting symptoms, or length or diameter of the stent. CONCLUSIONS: Based on our experience, in-stent restenosis followed by inflow lesions in the common femoral vein are the most common causes of stent thrombosis. These data suggest a need for future research to target these areas.

Effect of venous access site on postintervention stent thrombosis for nonthrombotic iliac vein stenting.

OBJECTIVE: Prior literature suggests that routine femoral vein (FV) puncture is necessary for interrogation of the iliac veins for stenosis to avoid missing common femoral vein (CFV) lesions. However, this can be technically challenging and poses small but increased risks. The purpose of this study was to compare the incidence of stent thrombosis after iliac vein stenting in the treatment of nonthrombotic iliac vein lesions with use of two discrete venous access sites-the CFV and FV. METHODS: During 4 years, we performed 1605 lower extremity venography studies with intravascular ultrasound (IVUS). There were 372 men and 689 women with an average age of 66 years (range, 21-99 years; standard deviation [SD], ± 14.3 years). After IVUS interrogation, 1513 procedures resulted in venous stenting; 964 patients received stent placement in the common iliac vein, 513 in the external iliac vein, 24 involving the CFV, and 12 involving the FV. The venous puncture site, accessed by ultrasound guidance, varied between the CFV and FV per the surgeon's choice and was documented on the basis of the most distal vein area measured by IVUS during the procedure. Patients were followed up with iliocaval and lower extremity duplex ultrasound within 2 weeks and every 3 months thereafter for the first year. RESULTS: There were 994 patients who received CFV puncture and 611 patients who received FV puncture. In 39 (4.2%) patients receiving CFV punctures with subsequent stent placement, any stent thrombosis developed within 30 days of the intervention; 27 (69.2%) were complete thromboses. In 21 (3.6%) patients who received FV punctures with subsequent stent placement, any stent thrombosis developed within 30 days of intervention; 17 (81.0%) were complete thromboses. There was no significant difference (P = .57) in ≤30-day thromboses between the CFV and FV cohorts. Any in-stent thrombosis developed >30 days after intervention in 18 patients, 11 in limbs that received CFV puncture and 7 with FV puncture (P = .98). Complete stent occlusion occurred in three cases of CFV puncture. No FV punctures led to >30-day complete stent thromboses. The median time to diagnosis of >30-day thrombosis was 11.1 months (range, 2.6-31.9 months; SD, ± 12.86 months). Median follow-up was 20 months (SD, ± 19.18 months). CONCLUSIONS: There was no significant difference between in-stent thrombosis rate and location of initial venous puncture in the setting of outpatient IVUS-guided venography. Both the CFV and FV can be safely used as puncture sites for lower extremity venography.

High-fraction brookite films from amorphous precursors.

Structure-specific synthesis processes are of key importance to the growth of polymorphic functional compounds such as TiO2, where material properties strongly depend on structure as well as chemistry. The robust growth of the brookite polymorph of TiO2, a promising photocatalyst, has been difficult in both powder and thin-film forms due to the disparity of reported synthesis techniques, their highly specific nature, and lack of mechanistic understanding. In this work, we report the growth of high-fraction (~95%) brookite thin films prepared by annealing amorphous titania precursor films deposited by pulsed laser deposition. We characterize the crystallization process, eliminating the previously suggested roles of substrate templating and Na helper ions in driving brookite formation. Instead, we link phase selection directly to film thickness, offering a novel, generalizable route to brookite growth that does not rely on the presence of extraneous elements or particular lattice-matched substrates. In addition to providing a new synthesis route to brookite thin films, our results take a step towards resolving the problem of phase selection in TiO2 growth, contributing to the further development of this promising functional material.