[Cutaneous squamous cell carcinoma of the head and neck]. / Kutane Plattenepithelkarzinome im Kopf- und Halsbereich.

OBJECTIVE: Cutaneous squamous cell carcinoma (cSCC), predominantly located on the scalp and face, is the second most prevalent skin cancer globally. Due to the increasing elderly population and rising incidence of cSCC, it has been gaining relevance in otorhinolaryngology. MATERIAL AND METHODS: This review article is based on a selective PubMed literature search, German and European guidelines and the clinic's own experience. RESULTS: In addition to chronic UV exposure, a disruption of the body's own immune system is becoming increasingly important. Vertical tumor thickness is associated with the highest risk of metastatic spread and local recurrence. Other significant risk factors are: horizontal tumor diameter, dedifferentiation, desmoplasia, perineural growth and localization on the face. Most cases are manageable by local excision with histological control of the excision margins. If regional metastases are clinically suspected, the draining cervical lymph node levels should be dissected depending on primary tumor location. cSCC of the upper face and the auricle primarily metastasize to the parotid gland. With the approval of the PD-1-blocking antibody cemiplimab in Europe, an active ingredient has been made available for the treatment of advanced cSCC where surgery or radiotherapy are no longer an option. CONCLUSIONS: The otherwise very low mortality rate of cSCC increases considerably with metastases. Therefore, imaging, surgical therapy and follow-up intervals should be based on risk factors. This allows early detection of metastases or local recurrences and improves the prognosis.

In vitro comparison of self-expanding versus balloon-expandable stents in a human ex vivo model.

The objective was to compare the radial strength and expansile precision of self-expanding stents and balloon-expandable stents in a human cadaver bifurcation model. Seven different self-expanding (LUMINEXX, JOSTENT SelfX, JOSTENT SelfX hrf, Sinus-Repo, Sinus SuperFlex, Easy Wallstent, SMART) and four different balloon-expandable stent models (Palmaz, Sinus Stent, SAXX Medium, JOSTENT peripheral), each type 10 stents (total n = 110 stents) were implanted into the common iliac arteries of human cadaver corpses. The maximum stent diameter was 10 mm for all models. After stent implantation, the specimens were filled with silicone caoutchouc. After 24 h, the vascular walls including the stents were removed from the hardened casts. Diameters were taken and the weight of the cast cylinders was measured in air and in purified water to calculate the volume of the bodies (according to Archimedes Law) as a relative but precise degree for the radial strength of the implanted stents. The cylindrical casts of the self-expanding stents showed lower mean diameters (8.2 +/- 1.0 mm) and mean volumes (0.60 +/- 0.14 ml/cm) than in the balloon-expandable stent group (10.1 +/- 0.3 mm and 0.71 +/- 0.04 ml/cm, respectively; p < 0.01). The nominal maximum diameter of 10 mm was not achieved in any of the self-expanding stents, but this was achieved in more than 70% (29/40) of the balloon-expandable stent specimens (p < 0.05). The variation between achieved volumes was significantly larger in self-expanding (range: 0.23-0.78 ml/cm) than in balloon-expandable stents (range: 0.66-0.81 ml/cm; p < 0.05). Self-expanding stents presented considerably lower radial expansion force and lower degree of precision than balloon-expandable stents.

Resistance to hoop stress in balloon expandable stents: evaluation in an ex vivo model.

RATIONALE AND OBJECTIVES: To develop a new model for a more realistic evaluation of radial strength and elastic recoil of balloon expandable stents using a new ex vivo model in human cadaver bifurcations of the aorta. MATERIALS AND METHODS: Four different stents (each group n = 10) were implanted in cadaver common iliac arteries. Randomization was performed either to right or left iliac artery. The specimens were cast filled with silicone caoutchouc and after 24 hours the vascular walls including the stents were removed from the hardened casts. The weight of the cast cylinders of the stents was measured in air and in purified water: the difference of the two values resulted in the buoyancy force and because of that the volume of the bodies as a relative degree for the radial strength could be calculated. The findings were correlated with the workbench tests of the manufacturers. RESULTS: Manufacturer's workbench tests were incomparable because of wide spread specifications. There was a significant difference between the theoretical maximal volume (0.866 mL) and the real cast volumes ( P< 0.025) that corresponds directly to the elastic recoil of the stents. The following mean real cast volumes were measured (corrected for 1 cm): Sinus-Stent 0.677 mL, Palmaz-Stent 0.708 mL, Jostent 0.715 mL, Saxx-Stent 0.732 mL, thus reflecting the various degree of radial strength; therefore, the ranking in radial strength resistance was Saxx, Jostent, Palmaz, and Sinus. CONCLUSION: High radial strength and low elastic recoil are important requirements of any stent design. Ex vivo tests unlike in vitro physical testing facilitate a realistic evaluation of the inherent stent characteristics. The model used in this study proved to be uniformly valid for physical stent design testing.