Human Papillomavirus (HPV) oral lesions surgical management with Nd:YAG laser versus blade and QMR scalpel: a single center experience in 251 cases.

HPVs are a large and varied group of viruses capable of infecting both animals and humans. They have evolved together with their respective hosts and are isolable in different and numerous species of birds, reptiles, marsupials and mammals. The present study aims to analyze and compare the epidemiological aspects of 251 HPV-associated benign lesions treated with three different surgical approaches. Between January 2004 and December 2019, 251 HPV-associated benign lesions (papillomas and / or condylomas) were treated at the Center of Medicina e Patologia Orale Laser Assistita of the University of Parma. After loco-regional anesthesia, the excisional biopsy was performed with A): 15C scalpel blade; B): molecular quantum resonance scalpel (RQM); C): Nd: YAG laser (1064 mn, 3.5W, 70Hz). The epidemiological analysis considered: gender, age, site of the lesion, surgical technique and recurrence. Our study did not show substantial differences in gender prevalence and the mean age of 50 years (minimum 8 years, maximum 85 years). Our study showed that HPV-associated lesions are localized in almost half of patients (47.9%) on the tongue or hard palate, less frequently on the cheeks (16.3%) and on the upper or lower lip (14,4) and in less than 10% of patients in the soft palate. Our study showed a low relapse rate (3%) for all three therapeutic approaches used, meaning that the cold blade, RQM scalpel and Nd: YAG laser can be successfully used to treat lesions associated with HPV, the laser approach has proved to be slightly more effective: probably thanks to the radicalization obtained through carbonization of the biopsy surrounding tissues. Since a small group of these viruses are the responsible agent of several types of human cancers (including squamous cell carcinoma of the oral cavity), early screening and treatment of HPV-associated lesions is essential to prevent the development of oncological diseases.

Correlation between temperature rise and auto-fluorescence: ex vivo study with Er:YAG laser, Quantum Molecular Resonance scalpel and Nd:YAG laser on hard and soft tissues.

Surgical techniques of soft and hard oral tissues highly benefited from new technologies such as the Quantic Molecular Resonance (QMR) lancet, the Neodymium-doped Yttrium Aluminum Garnet (Nd:YAG) laser and the Erbium-doped Yttrium Aluminum Garnet (Er:YAG) laser. Increasingly, these technologies replace scalpel, conventional electrosurgery and traditional rotary surgery instruments due to their proven advantages. Features such as reduction of the surgical time, more efficient bleeding control resulting in higher intra-operative visibility and improvement of postoperative course with better Quality of Life score (QoL) are highlighted in numerous studies published in the literature. The thermal rise of tissues during surgical incision, performed with other instruments rather than traditional cold blade scalpels, is not to be ignored by the operator and it must take into consideration first when choosing the surgical instrument and then throughout all the surgical act. Auto-fluorescence (AF) is a property possessed by every cell that exposed to a specific wavelength can absorbance or reflect with peculiar characteristics and its direct examination has been proposed as a non-invasive visual tool for investigation of suspicious changes in oral mucosa. At the limit of our knowledge, few studies have been published in the literature regarding tissue's temperature variations and the interest in Infra-Red temperature detection has been shown in various medicine fields and none of published studies investigated the possible correlation between temperature raise and AF variations. This ex vivo study aims to analyse and compare through the use of a thermal imaging camera and simultaneous detection of AF, the possible correlation between temperature increase and auto-fluorescence.

Absorption and diffusion of a 645 nm diode laser beam in the bone. An ex vivo study.

The present preliminary ex vivo study aims to assess the possible interaction between complex biological systems and laser light, through irradiation of different hard tissue samples. A 645 nm wavelength diode laser was adopted to perform the present evaluation. Due to known similarities to human tissues, swine tissue samples were used. Two samples of cortical bone measuring 4.4 mm and 4.7 mm of thickness and 2 samples of spongeous bone measuring 2.45 mm and 2.9 mm were harvested for the analysis of hard tissues. Mean absorption values were as follows: 128.82 mW standard deviation 8.74 for 2.45 mm spongeous bone sample; 132.34 mW standard deviation 7.66 for 2.9 mm spongeous bone sample; 140.59 mW standard deviation 5.97 for 4.4 mm cortical bone sample and 152.20 mW standard deviation 3.36 for 4.7 mm mucosa and cortical bone sample. Red-light laser with 645nm wavelength has the ability to reach cells in each layer of measured tissues.

Epithelial cell kinetics in the remaining colorectal mucosa after surgery for cancer of the large bowel.

We used microautoradiography in order to evaluate cell replication of the remaining colorectal mucosa in 20 patients previously operated on for cancer of the large bowel. The results were compared to those of 24 controls without neoplasms or other relevant colorectal disease. Samples of colorectal mucosa were taken during endoscopy. At histological examination each labeled intestinal hemicrypt was divided into 5 longitudinal compartments, from the base to the surface, and S-phase cells in each compartment were counted. Total labeling index (LI, ratio of labeled to total cells x 100) and labeling index per crypt compartment were similar in surgical patients and in controls. In contrast, both total LI and labeling index in the upper portions of the crypt (compartments 3, 4, and 5) were significantly higher in the 9 patients who showed recurrence of polyps than in those (n = 11) without recurrence. The LI in compartments 4 and 5 (the "high crypt region") was 4.37 +/- 0.95 (SEM) in patients with recurrence versus 0.88 +/- 0.21 (P less than 0.001) in patients with negative endoscopy finding and 1.47 +/- 0.22 in controls. Moreover, the fifth compartment was labeled in 8 of 9 individuals in whom polyps recurred but in only 2 of 11 patients without recurrence and 3 of 24 controls. In conclusion, after resection for large bowel cancer colonic epithelial cell proliferation tends to become more quiescent and similar to that of controls. However, in the subgroup of patients in whom polyps reappear, the colorectal mucosa maintains a hyperproliferative state with an expansion of the replicative zone to the most superficial portions of the crypt. These findings support the sequence adenoma-carcinoma and suggest that the evaluation of cell proliferation might be useful in the identification of subjects at increased risk for multiple tumors of the large bowel.