Endoscopy

Endoscopy is a fast moving field, and new techniques are continuously emerging. In recent decades, endoscopy has evolved and branched out from a diagnostic modality to enhanced video and computer assisting imaging with impressive interventional capabilities. The modern endoscopy has seen advances not only in types of endoscopes available, but also in types of interventions amenable to the endoscopic approach. To date, there are a lot more developments that are being trialed. Modern endoscopic equipment provides physicians with the benefit of many technical advances. Endoscopy is an effective and safe procedure even in special populations including pediatric patients and renal transplant patients. It serves as the tool for diagnosis and therapeutic interventions of many organs including gastrointestinal tract, head and neck, urinary tract and others

Pathophysiology and Surgical Treatment of Eustachian Tube Dysfunction

Tämän tutkimuksen tarkoituksena oli kehittää menetelmiä videoendoskopian yhteydessä tapahtuvaan korvatorventoiminnan määrälliseen analyysiin, ja soveltaa hankittuja tietoja uusien kirurgisten toimenpiteiden kehittämiseen itsepintaisen laajentumisvajaatoiminnan tai tuba apertan toimintahäiriön hoidossa. Ennakoivat tutkimukset tehtiin keskussairaaloissa normaaleille aikuisille ja potilaille joilla oli välikorvatulehdus eritteen kanssa (OME) tai tuba aperta, ja kadavereilla. Parametrit mitattiin endoskooppivideoilta. Samanaikainen sonotubometry ja endoskopia tehtiin terveille henkilöille. Potilaat, joilla oli itsepintainen OME saivat laser korvatorven tuboplasty (LETP) jossa poltettiin posteromedialiseinässä lumeen limakalvoa, submukoosaa, ja joskus myös rustoa. Korvatorven pallolaajennus toimenpiteen mahdollisuuksia ja turvallisuutta tutkittiin kadaverien ja sen jälkeen potilaiden korvatorvissa. Tuba aperta korjattiin täyttämällä kirurgisesti kovera puute anteriorilateraalisessa seinässä. Korvatorvessa on toimiva läppä rustoisessa segmentissä ja sen toimintahäiriö voi johtaa välikorvan tautiin. Näimme videoendoskopialla että lateraaliseinän liikkuvuus väheni potilaissa joilla on OME tai tuba aperta. Voisimme tutkia lisää seinän lateraaliliikkuvuutta ymmärtääksemme korvatorven patofysiologiaa. Korvatorvi ei avautunut kaikissa normaaleissa henkilöissä sonotubometrialla, mutta oli tarkemmin määritelty kuin videoendoskopialla kun se tapahtui. Yhdistetty teknologia tarjoaa lisää tietoa ja on lupaava tulevaisuutta ajatellen. LETP oli turvallinen, ilman merkittäviä komplikaatioita, ja voisi parantaa vakavasti itsepintaisen OME:n. Korvatorven pallolaajennus oli turvallinen ja teknisesti toteuttamiskelpoinen, ja sillä on kohtuullinen mahdollisuus kliiniseen tehokkuuteen. Nyt olisi tärkeä tehdä satunnaistettuja kliinisiä tutkimuksia toimenpiteestä. Tuba aperta toimenpide onnistui lievittämään oireita ja tulevaisuudessa tarvitsemme parempia välineitä ja siirrännäiskudosta.The purpose of this study was to develop methods for quantitative analysis of Eustachian tube (ET) function to supplement video endoscopy and to apply the knowledge gained to the creation of new surgical procedures to treat refractory dilatory or patulous dysfunction of the ET. Prospective studies were performed on adult normal subjects and patients with otitis media with effusion (OME) or patulous ETs in tertiary medical centers and on human cadaver heads. Timing and metric parameters were measured from the endoscopic videos. Analyses of endoscopy with simultaneous sonotubometry were conducted in normal subjects. Patients with refractory OME underwent laser Eustachian tuboplasty (LETP) procedures to vaporize mucosa, submucosa, and cartilage, thinning the postero-medial wall of the ET. The feasibility and safety of an alternative procedure, balloon dilation of the ET was investigated in cadavers and then performed on patients with refractory OME. Patients with patulous ETs underwent surgical augmentation of the concave defect found in the antero-lateral wall. Diagnostic analyses were done on 27 normal, 13 OME and 15 patulous subjects. Mean values for normals: angle of torus tubarius rotation 34.2° (SD 14.3) and excursion of the antero-lateral wall 35.5 % of torus tubarius height (SD 16.3). Lateral excursion wall was significantly less in patulous ET (18.7%, SD 15.1, p=0.001) and in OME (23.9%, SD 21.7, p=0.048). During sonotubometery, all showed normal endoscopy and appeared to open, but only 11/17 opened by objective criteria of 5 dB increase in signal with swallows (ave. duration 0.43 s) and 13/17 with yawns (ave.2.03s). LETP in conjunction with tympanostomy tube was performed in 13 patients and eliminated OME in 4/11 at 6 months, 3/10 at 1 year, and 3/8 at 2 years. Balloon dilation catheters successfully dilated all cadaver ETs without significant adverse effects and average tubal volume increased from 0.16 to 0.49 cm3 (SD 0.12). In 11 patients undergoing balloon dilation, all cases successfully dilated. 11/11 could autoinsufflate by Valsalva (p The ET contains a functional valve within the cartilaginous segment and its failure may leads to middle ear disorders. On video endoscopy, lateral excursion of the antero-lateral wall was reduced in OME and patulous ETs. This parameter can now be further studied in the search for pathophysiology of tubal dysfunction. Sonotubometry failed to record tubal opening in all subjects, but when it occurred it was more accurately determined than by endoscopy. The combined technology provides complimentary information and is promising for future use. LETP was safe, without significant complications, and could improve severely refractory OME. It is promising for expanded indications in ET surgery. Alternatively, balloon dilation was shown to be safe, technically feasible and with some reasonable possibility for clinical efficacy. Randomized clinical trials of the procedure are indicated. Patulous ET reconstruction was successful in relieving symptoms and future work is needed to improve the instrumentation and graft materials

Comparative study between Conventional Adenoid Curettage and Endoscopic Assisted Adenoid Curettage

Adenoidectomy is a common procedure done for various causes like chronic adenoiditis or chronic adenotonsillitis or adenoid hypertrophy with middle ear and sinus disorders. Clinical features includes rhinorrhea, chronic mouth breathing, excessive snoring, apneic episodes, enuresis, daytime somnolence, neurocognitive and learning problems. Adenoidectomy provides a symptomatic recovery with improvement in the quality of life and health status of the patients. In this study we discussed on COMPARATIVE STUDY BETWEEN CONVENTIONAL ADENOID CURETTAGE AND ENDOSCOPIC ASSISTED ADENOID CURETTAGE. The results we obtained suggested that the endoscopic assisted adenoid curettage is comparatively better in the post operative tissue remnant, Eustachian tube injury, symptomatic relief

Spatial frequency domain imaging towards improved detection of gastrointestinal cancers

Early detection and treatment of gastrointestinal cancers has been shown to drastically improve patients survival rates. However, wide population based screening for gastrointestinal cancers is not feasible due to its high cost, risk of potential complications, and time consuming nature. This thesis forms the proposal for the development of a cost-effective, minimally invasive device to return quantitative tissue information for gastrointestinal cancer detection in-vivo using spatial frequency domain imaging (SFDI). SFDI is a non-invasive imaging technique which can return close to real time maps of absorption and reduced scattering coefficients by projecting a 2D sinusoidal pattern onto a sample of interest. First a low-cost, conventional bench top system was constructed to characterise tissue mimicking phantoms. Phantoms were fabricated with specific absorption and reduced scattering coefficients, mimicking the variation in optical properties typically seen in healthy, cancerous, and pre-cancerous oesophageal tissue. The system shows accurate retrieval of absorption and reduced scattering coefficients of 19% and 11% error respectively. However, this bench top system consists of a bulky projector and is therefore not feasible for in-vivo imaging. For SFDI systems to be feasible for in-vivo imaging, they are required to be miniaturised. Many conditions must be considered when doing this such as various illumination conditions, lighting conditions and system geometries. Therefore to aid in the miniaturisation of the bench top system, an SFDI system was simulated in the open-source ray tracing software Blender, where the capability to simulate these conditions is possible. A material of tunable absorption and scattering properties was characterised such that the specific absorption and reduced scattering coefficients of the material were known. The simulated system shows capability in detecting optical properties of typical gastrointestinal conditions in an up-close, planar geometry, as well in a non-planar geometry of a tube simulating a lumen. Optical property imaging in the non-planar, tubular geometry was done with the use of a novel illumination pattern, developed for this work. Finally, using the knowledge gained from the simulation model, the bench top system was miniaturised to a 3 mm diameter prototype. The novel use of a fiber array producing the necessary interfering fringe patterns replaced the bulky projector. The system showed capability to image phantoms simulating typical gastrointestinal conditions at two wavelengths (515 and 660 nm), measuring absorption and reduced scattering coefficients with 15% and 6% accuracy in comparison to the bench top system for the fabricated phantoms. It is proposed that this system may be used for cost-effective, minimally invasive, quantitative imaging of the gastrointestinal tract in-vivo, providing enhanced contrast for difficult to detect cancers

SURGICAL NAVIGATION AND AUGMENTED REALITY FOR MARGINS CONTROL IN HEAD AND NECK CANCER

I tumori maligni del distretto testa-collo rappresentano un insieme di lesioni dalle diverse caratteristiche patologiche, epidemiologiche e prognostiche. Per una porzione considerevole di tali patologie, l’intervento chirurgico finalizzato all’asportazione completa del tumore rappresenta l’elemento chiave del trattamento, quand’anche esso includa altre modalità quali la radioterapia e la terapia sistemica. La qualità dell’atto chirurgico ablativo è pertanto essenziale al fine di garantire le massime chance di cura al paziente. Nell’ambito della chirurgia oncologica, la qualità delle ablazioni viene misurata attraverso l’analisi dello stato dei margini di resezione. Oltre a rappresentare un surrogato della qualità della resezione chirurgica, lo stato dei margini di resezione ha notevoli implicazioni da un punto di vista clinico e prognostico. Infatti, il coinvolgimento dei margini di resezione da parte della neoplasia rappresenta invariabilmente un fattore prognostico sfavorevole, oltre che implicare la necessità di intensificare i trattamenti postchirurgici (e.g., ponendo indicazione alla chemioradioterapia adiuvante), comportando una maggiore tossicità per il paziente. La proporzione di resezioni con margini positivi (i.e., coinvolti dalla neoplasia) nel distretto testa-collo è tra le più elevate in ambito di chirurgia oncologica. In tale contesto si pone l’obiettivo del dottorato di cui questa tesi riporta i risultati. Le due tecnologie di cui si è analizzata l’utilità in termini di ottimizzazione dello stato dei margini di resezione sono la navigazione chirurgica con rendering tridimensionale e la realtà aumentata basata sulla videoproiezione di immagini. Le sperimentazioni sono state svolte parzialmente presso l’Università degli Studi di Brescia, parzialmente presso l’Azienda Ospedale Università di Padova e parzialmente presso l’University Health Network (Toronto, Ontario, Canada). I risultati delle sperimentazioni incluse in questo elaborato dimostrano che l'impiego della navigazione chirurgica con rendering tridimensionale nel contesto di procedure oncologiche ablative cervico-cefaliche risulta associata ad un vantaggio significativo in termini di riduzione della frequenza di margini positivi. Al contrario, le tecniche di realtà aumentata basata sulla videoproiezione, nell'ambito della sperimentazione preclinica effettuata, non sono risultate associate a vantaggi sufficienti per poter considerare tale tecnologia per la traslazione clinica.Head and neck malignancies are an heterogeneous group of tumors. Surgery represents the mainstay of treatment for the large majority of head and neck cancers, with ablation being aimed at removing completely the tumor. Radiotherapy and systemic therapy have also a substantial role in the multidisciplinary management of head and neck cancers. The quality of surgical ablation is intimately related to margin status evaluated at a microscopic level. Indeed, margin involvement has a remarkably negative effect on prognosis of patients and mandates the escalation of postoperative treatment by adding concomitant chemotherapy to radiotherapy and accordingly increasing the toxicity of overall treatment. The rate of margin involvement in the head and neck is among the highest in the entire field of surgical oncology. In this context, the present PhD project was aimed at testing the utility of 2 technologies, namely surgical navigation with 3-dimensional rendering and pico projector-based augmented reality, in decreasing the rate of involved margins during oncologic surgical ablations in the craniofacial area. Experiments were performed in the University of Brescia, University of Padua, and University Health Network (Toronto, Ontario, Canada). The research activities completed in the context of this PhD course demonstrated that surgical navigation with 3-dimensional rendering confers a higher quality to oncologic ablations in the head and neck, irrespective of the open or endoscopic surgical technique. The benefits deriving from this implementation come with no relevant drawbacks from a logistical and practical standpoint, nor were major adverse events observed. Thus, implementation of this technology into the standard care is the logical proposed step forward. However, the genuine presence of a prognostic advantage needs longer and larger study to be formally addressed. On the other hand, pico projector-based augmented reality showed no sufficient advantages to encourage translation into the clinical setting. Although observing a clear practical advantage deriving from the projection of osteotomy lines onto the surgical field, no substantial benefits were measured when comparing this technology with surgical navigation with 3-dimensional rendering. Yet recognizing a potential value of this technology from an educational standpoint, the performance displayed in the preclinical setting in terms of surgical margins optimization is not in favor of a clinical translation with this specific aim

Minimally invasive tubular retraction and transtubular approaches in neurosurgery

Minimally invasive surgical approaches have revolutionized surgical care and are becoming increasingly common and sought after in neurosurgery. Despite significant advancements in these techniques and associated technologies, the use of spatulas, that remain essentially unchanged since the late 1800s, for brain retraction endures as a mainstay of neurosurgical practice. In the last decade, tubular retractors have been successfully used in the management of deep-seated intraparenchymal and intraventricular lesions but have yet to be used to minimize brain retraction in skull base surgery. In order to determine the full applicability of transtubular techniques in neurosurgery, we compare brain retraction pressures between tubular retractors and brain spatulas in common neurosurgical approaches, assess the feasibility of performing minimally invasive transtubular skull base and general neurosurgical approaches, and introduce a novel technique for closure of transtubular minicraniectomies with maintenance of anatomic integrity. In all approaches assessed, tubular retraction resulted in average brain retraction pressures that were 57% less collectively than those resulting from spatula retraction. Tubular retractors demonstrated more consistent average retraction pressures between approaches and required 50% less mean retraction distance compared to spatula retractors, while cortical tearing was observed microscopically in 39% of cases following spatula retraction. Transtubular supraorbital, anterior transpetrosal, interhemispheric transcallosal, retrosigmoid, and supracerebellar infratentorial approaches are safe and effective surgical corridors to their respective intracranial targets, with ample surgical exposure, freedom, and maneuverability and minimal retraction of brain tissue. The tubular retractor provided sufficient working space for standard bimanual surgical technique without obstruction of the visual field and permitted sufficient surgical freedom while allowing for constant monitoring of retracted tissues. Adequate preoperative planning of the surgical trajectory was critical for facilitating a safe, direct, and practicable surgical corridor. Closure of transtubular minicraniectomies could be accomplished by rapid on-demand 3D printing of patient-specific cranioprostheses which was found to be a novel, feasible, and inexpensive option that was accomplished with minimal technical difficulty. Tubular retraction in neurosurgery provides a safe and effective conduit for the application of percutaneous minimally invasive approaches while inducing substantially reduced brain retraction pressures than conventional spatula retractors. Advances in neuronavigation and surgical robotics will continue to expand the indications for tubular retraction in neurosurgery

Повезаност типова девијације носне преграде са тежином опструкционих симптома и карактеристикама протока ваздуха кроз носну дупљу

To investigate the association between the nasal septal deviation (NSD) morphology with nasal airway obstruction (NAO) symptom severity and the nasal airflow parameters. Methods: The study included 225 patients with diagnosed NSD. The Nasal Obstruction Symptom Evaluation (NOSE) questionnaire was validated and cross-culturally adapted for the Serbian population and applied for the NAO assessment. Patients were examined by computed tomography (CT). CT images were used to classify NSD according to Mladina's classification and generate eight 3D computational models of the nasal cavity (one model without NSD, seven models representing each Mladina's NSD type). Inspiration was simulated by computational fluid dynamics (CFD) method and analyzed through CFD parameters (airflow partitioning, velocity, wall shear stress, pressure, nasal resistance (NR), heat flux (HF), turbulent kinetic energy (k), and airflow pattern). The obtained data were statistically analyzed. Results: Although NOSE scores differed between patients with various Mladina's NSD types, the differences were not confirmed as statistically significant (B=0.837, p=0.261). There was no significant link between NSD types and NAO severity after applying additional morphology-based NSD classifications. CFD analysis showed that Mladina's NSD types induce various side asymmetry in all CFD parameters. CFD parameters that significantly correlated with the NOSE scores were: side asymmetry in NR (R=0.762, p=0.028), HF on the narrow nasal passage (R=-0.732, p=0.039), and ipsilateral k (R=-0.723, p=.043). Conclusions: NSD morphology could not predict NAO severity. Side asymmetry in NR, reduction in HF and k in the narrow nasal passage may contribute to the NSD-related NAO perception.испитати повезаност типова девијације носне преграде (ДНП) са тежином опструкционих симптома и параметрима протока ваздуха кроз носну дупљу. Метод: У студији је учествовало 225 пацијената са дијагностикованом ДНП. Упитник "Nasal Obstruction Symptom Evaluation (NOSE)" је валидиран и културално адаптиран за српску популацију и примењен за процену тежине опструкционих симптома. Снимци пацијената са апарата за компјутеризовану томографију (КТ) коришћени су за класификацију ДНП по Младининим критеријумима и за израду осам компјутерских модела носне дупље (један модел без ДНП, седам модела за сваки тип ДНП по Младини). Методом компјутеризоване динамике флуида (КДФ) симулирано је удисање на моделима и анализирани су параметри протока ваздуха кроз нос (дистрибуција удахнутог ваздуха између десне и леве стране, брзина, смичући напон, притисак, отпор, топлотни флукс (ТФ), турбулентна кинетичка енергија (ТКЕ) и образац протока). Добијени подаци су анализирани одговарајућим статистичким тестовима. Резултати: Иако су уочене разлике у NOSE скоровима међу Младининим типовима ДНП, исте нису биле статистички значајне (B=0.837, p=0.261). Такође није детектована статистичка веза између NOSE скорова и типова ДНП класификованих према другим критеријумима. КДФ анализа је показала постојање разлика у свим КДФ параметрима између Младининих типова ДНП. КДФ параметри који су значајно статистички повезани са NOSE скоровима су асиметрија у отпору између десне и леве стране (R=0.762, p=0.028), ТФ (R=-0.732, p=0.039) и ТКЕ (R=-0.723, p=.043) на страни сужења. Закључак: Није могућно предвидети тежину опструкционих симптома на основу морфологије ДНП. Асиметрија у отпору између страна носне дупље узрокована ДНП, редукција ТФ и ТКЕ на страни сужења могу бити одговорни за осећај опструкције

An Investigation of the Diagnostic Potential of Autofluorescence Lifetime Spectroscopy and Imaging for Label-Free Contrast of Disease

The work presented in this thesis aimed to study the application of fluorescence lifetime spectroscopy (FLS) and fluorescence lifetime imaging microscopy (FLIM) to investigate their potential for diagnostic contrast of diseased tissue with a particular emphasis on autofluorescence (AF) measurements of gastrointestinal (GI) disease. Initially, an ex vivo study utilising confocal FLIM was undertaken with 420 nm excitation to characterise the fluorescence lifetime (FL) images obtained from 71 GI samples from 35 patients. A significant decrease in FL was observed between normal colon and polyps (p = 0.024), and normal colon and inflammatory bowel disease (IBD) (p = 0.015). Confocal FLIM was also performed on 23 bladder samples. A longer, although not significant, FL for cancer was observed, in paired specimens (n = 5) instilled with a photosensitizer. The first in vivo study was a clinical investigation of skin cancer using a fibre-optic FL spectrofluorometer and involved the interrogation of 27 lesions from 25 patients. A significant decrease in the FL of basal cell carcinomas compared to healthy tissue was observed (p = 0.002) with 445 nm excitation. A novel clinically viable FLS fibre-optic probe was then applied ex vivo to measure 60 samples collected from 23 patients. In a paired analysis of neoplastic polyps and normal colon obtained from the same region of the colon in the same patient (n = 12), a significant decrease in FL was observed (p = 0.021) with 435 nm excitation. In contrast, with 375 nm excitation, the mean FL of IBD specimens (n = 4) was found to be longer than that of normal tissue, although not statistically significant. Finally, the FLS system was applied in vivo in 17 patients, with initial data indicating that 435 nm excitation results in AF lifetimes that are broadly consistent with ex vivo studies, although no diagnostically significant differences were observed in the signals obtained in vivo.Open Acces

PRELIMINARY FINDINGS OF A POTENZIATED PIEZOSURGERGICAL DEVICE AT THE RABBIT SKULL

The number of available ultrasonic osteotomes has remarkably increased. In vitro and in vivo studies have revealed differences between conventional osteotomes, such as rotating or sawing devices, and ultrasound-supported osteotomes (Piezosurgery®) regarding the micromorphology and roughness values of osteotomized bone surfaces. Objective: the present study compares the micro-morphologies and roughness values of osteotomized bone surfaces after the application of rotating and sawing devices, Piezosurgery Medical® and Piezosurgery Medical New Generation Powerful Handpiece. Methods: Fresh, standard-sized bony samples were taken from a rabbit skull using the following osteotomes: rotating and sawing devices, Piezosurgery Medical® and a Piezosurgery Medical New Generation Powerful Handpiece. The required duration of time for each osteotomy was recorded. Micromorphologies and roughness values to characterize the bone surfaces following the different osteotomy methods were described. The prepared surfaces were examined via light microscopy, environmental surface electron microscopy (ESEM), transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM) and atomic force microscopy. The selective cutting of mineralized tissues while preserving adjacent soft tissue (dura mater and nervous tissue) was studied. Bone necrosis of the osteotomy sites and the vitality of the osteocytes near the sectional plane were investigated, as well as the proportion of apoptosis or cell degeneration. Results and Conclusions: The potential positive effects on bone healing and reossification associated with different devices were evaluated and the comparative analysis among the different devices used was performed, in order to determine the best osteotomes to be employed during cranio-facial surgery