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1.
Br J Ophthalmol ; 2024 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-39216904

RESUMO

BACKGROUND/AIMS: It is unclear whether a reduction in tear secretion contributes to the discomfort experienced by those with prosthetic eyes. Tear secretion has hitherto only been measured with the Schirmer test which may be affected by the pooling of tears behind the prosthesis. In this study, direct imaging of the lacrimal gland has been performed to measure tear secretion in anophthalmic sockets. The relation between the area of meibomian glands and dry eye symptoms was also assessed. METHODS: 12 patients were included. The amount of tear secretion was measured by direct imaging of the lacrimal gland while the presence of meibomian glands was determined using meibography. The 5-item Dry Eye Questionnaire was used to assess symptoms of dry eye. RESULTS: No difference was found in tear secretion between the anophthalmic socket and the contralateral eye. The area of meibomian glands was significantly reduced in eyelids on the side of the prosthetic eye, compared with the contralateral eye. Seven patients reported symptoms indicative of dry eye in the anophthalmic socket, compared with only two in the contralateral eye. CONCLUSIONS: The effects of an eye prosthesis on meibomian glands may contribute to the frequently perceived symptoms of dry eye despite unaffected in tear secretion.

3.
Biomed Phys Eng Express ; 10(5)2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38959869

RESUMO

Objective. The availability of tissue-mimicking materials (TMMs) for manufacturing high-quality phantoms is crucial for standardization, evaluating novel quantitative approaches, and clinically translating new imaging modalities, such as photoacoustic imaging (PAI). Recently, a gel comprising the copolymer styrene-ethylene/butylene-styrene (SEBS) in mineral oil has shown significant potential as TMM due to its optical and acoustic properties akin to soft tissue. We propose using artists' oil-based inks dissolved and diluted in balsam turpentine to tune the optical properties.Approach. A TMM was fabricated by mixing a SEBS copolymer and mineral oil, supplemented with additives to tune its optical absorption and scattering properties independently. A systematic investigation of the tuning accuracies and relationships between concentrations of oil-based pigments and optical absorption properties of the TMM across visible and near-infrared wavelengths using collimated transmission spectroscopy was conducted. The photoacoustic spectrum of various oil-based inks was studied to analyze the effect of increasing concentration and depth.Main results. Artists' oil-based inks dissolved in turpentine proved effective as additives to tune the optical absorption properties of mineral oil SEBS-gel with high accuracy. The TMMs demonstrated long-term stability and suitability for producing phantoms with desired optical absorption properties for PAI studies.Significance. The findings, including tuning of optical absorption and spectral shape, suggest that this TMM facilitates the development of more sophisticated phantoms of arbitrary shapes. This approach holds promise for advancing the development of PAI, including investigation of the spectral coloring effect. In addition, it can potentially aid in the development and clinical translation of ultrasound optical tomography.


Assuntos
Imagens de Fantasmas , Técnicas Fotoacústicas , Polímeros , Técnicas Fotoacústicas/métodos , Polímeros/química , Óleo Mineral/química , Tinta , Materiais Biomiméticos/química , Humanos , Terebintina/química , Óleos/química
4.
iScience ; 27(5): 109653, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38680659

RESUMO

In the dawning era of artificial intelligence (AI), health care stands to undergo a significant transformation with the increasing digitalization of patient data. Digital imaging, in particular, will serve as an important platform for AI to aid decision making and diagnostics. A growing number of studies demonstrate the potential of automatic pre-surgical skin tumor delineation, which could have tremendous impact on clinical practice. However, current methods rely on having ground truth images in which tumor borders are already identified, which is not clinically possible. We report a novel approach where hyperspectral images provide spectra from small regions representing healthy tissue and tumor, which are used to generate prediction maps using artificial neural networks (ANNs), after which a segmentation algorithm automatically identifies the tumor borders. This circumvents the need for ground truth images, since an ANN model is trained with data from each individual patient, representing a more clinically relevant approach.

5.
Orbit ; 43(4): 453-463, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38591750

RESUMO

PURPOSE: The gold standard for skin cancer diagnosis is surgical excisional biopsy and histopathological examination. Several non-invasive diagnostic techniques exist, although they have not yet translated into clinical use. This is a proof-of-concept study to assess the possibility of imaging an angiosarcoma in the periocular area. METHODS: We use laser speckle, hyperspectral, and photoacoustic imaging to monitor blood perfusion and oxygen saturation, as well as the molecular composition of the tissue. The information obtained from each imaging modality was combined in order to yield a more comprehensive picture of the function, as well as molecular composition of a rapidly growing cutaneous angiosarcoma in the periocular area. RESULTS: We found an increase in perfusion coupled with a reduction in oxygen saturation in the angiosarcoma. We could also extract the molecular composition of the angiosarcoma at a depth, depicting both the oxygen saturation and highlighting the presence of connective tissue via collagen. CONCLUSIONS: We demonstrate the different physiological parameters that can be obtained with the different techniques and how these can be combined to provide detailed 3D maps of the functional and molecular properties of tumors useful in preoperative assessment.


Assuntos
Hemangiossarcoma , Imageamento Tridimensional , Técnicas Fotoacústicas , Humanos , Hemangiossarcoma/diagnóstico por imagem , Hemangiossarcoma/patologia , Neoplasias Cutâneas/diagnóstico por imagem , Neoplasias Cutâneas/patologia , Imageamento Hiperespectral , Oxigênio/sangue , Masculino , Feminino , Lasers , Estudo de Prova de Conceito
6.
Orbit ; 43(4): 464-470, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38687914

RESUMO

PURPOSE: In oculoplastic surgery the eyelid tissue is frequently stretched in order to repair defects after tumor surgery. However, there is a paucity of research regarding how stretching affects eyelids. The purpose of this study was to gain insight into how traction force affects eyelid stretch as well as tissue perfusion, using a laser-based in vivo monitoring technique. METHOD: Lower-lid pentagonal resections were performed in eight patients and a total of nine eyelids. The medial section of the eyelid was then stretched using a dynamometer up to a force of 2.3 Newtons (N), and eyelid stretching and blood perfusion were continuously measured using laser speckle contrast imaging. RESULTS: Tissue perfusion decreased exponentially when eyelid tissue was stretched, with an initial sharp decline followed by a more gradual reduction. Perfusion approached zero at a force of approximately 2.0 N. The length of the eyelid increased with increasing force up to 1.5 N, after which there was only a very slight increase in length. CONCLUSIONS: Eyelid tissue seems to respond to traction in a non-linear fashion, where the initial force results in the greatest eyelid stretching and reduction in blood perfusion. The results provide information on the effects of a large force for direct closure of large eyelid defects. Considering how quickly perfusion approaches zero, the high success rate of eyelid reconstruction surgery is likely a testament to the extensive vascularization of the periocular region.


Assuntos
Pálpebras , Fluxo Sanguíneo Regional , Humanos , Pálpebras/cirurgia , Pálpebras/irrigação sanguínea , Feminino , Masculino , Idoso , Fluxo Sanguíneo Regional/fisiologia , Pessoa de Meia-Idade , Tração , Imagem de Contraste de Manchas a Laser , Neoplasias Palpebrais/cirurgia , Neoplasias Palpebrais/fisiopatologia , Idoso de 80 Anos ou mais , Procedimentos de Cirurgia Plástica/métodos , Blefaroplastia/métodos
7.
Biomed Opt Express ; 15(3): 1995-2013, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38495727

RESUMO

Clinical determination of oxygen saturation (sO2) in patients is commonly performed via non-invasive optical techniques. However, reliance on a few wavelengths and some form of pre-determined calibration introduces limits to how these methods can be used. One example involves the assessment of sO2 after injection of local anesthetic using epinephrine, where some controversy exists around the time it takes for the epinephrine to have an effect. This is likely caused by a change in the tissue environment not accounted for by standard calibrated instruments and conventional analysis techniques. The present study aims to account for this changing environment by acquiring absorption spectra using hyperspectral imaging (HSI) and diffuse reflectance spectroscopy (DRS) before, during, and after the injection of local anesthesia containing epinephrine in human volunteers. We demonstrate the need to account for multiple absorbing species when applying linear spectral unmixing in order to obtain more clinically relevant sO2 values. In particular, we demonstrate how the inclusion of water absorption greatly affects the rate at which sO2 seemingly drops, which in turn sheds light on the current debate regarding the time required for local anesthesia with epinephrine to have an effect. In general, this work provides important insight into how spectral analysis methods need to be adapted to specific clinical scenarios to more accurately assess sO2.

8.
Diagnostics (Basel) ; 13(19)2023 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-37835819

RESUMO

This study aims to investigate the feasibility of using diffuse reflectance spectroscopy (DRS) to distinguish malignant breast tissue from adjacent healthy tissue, and to evaluate if an extended-wavelength range (450-1550 nm) has an advantage over the standard wavelength range (450-900 nm). Multivariate statistics and machine learning algorithms, either linear discriminant analysis (LDA) or support vector machine (SVM) are used to distinguish the two tissue types in breast specimens (total or partial mastectomy) from 23 female patients with primary breast cancer. EW-DRS has a sensitivity of 94% and specificity of 91% as compared to a sensitivity of 40% and specificity of 71% using the standard wavelength range. The results suggest that DRS can discriminate between malignant and healthy breast tissue, with improved outcomes using an extended wavelength. It is also possible to construct a simple analytical model to improve the diagnostic performance of the DRS technique.

9.
Microvasc Res ; 150: 104573, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37390964

RESUMO

BACKGROUND: Optical spectroscopy is commonly used clinically to monitor oxygen saturation in tissue. The most commonly employed technique is pulse oximetry, which provides a point measurement of the arterial oxygen saturation and is commonly used for monitoring systemic hemodynamics, e.g. during anesthesia. Hyperspectral imaging (HSI) is an emerging technology that enables spatially resolved mapping of oxygen saturation in tissue (sO2), but needs to be further developed before implemented in clinical practice. The aim of this study is to demonstrate the applicability of HSI for mapping the sO2 in reconstructive surgery and demonstrate how spectral analysis can be used to obtain clinically relevant sO2 values. METHODS: Spatial scanning HSI was performed on cutaneous forehead flaps, raised as part of a direct brow lift, in eight patients. Pixel-by-pixel spectral analysis, accounting for the absorption from multiple chromophores, was performed and compared to previous analysis techniques to assess sO2. RESULTS: Spectral unmixing using a broad spectral range, and accounting for the absorption of melanin, fat, collagen, and water, provided a more clinically relevant estimate of sO2 than conventional techniques, where typically only spectral features associated with absorption of oxygenated (HbO2) and deoxygenated (HbR) hemoglobin are considered. We demonstrate its clinical applicability by generating sO2 maps of partially excised forehead flaps showed a gradual decrease in sO2 along the length of the flap from 95 % at the flap base to 85 % at the flap tip. After being fully excised, sO2 in the entire flap decreased to 50 % within a few minutes. CONCLUSIONS: The results demonstrate the capability of sO2 mapping in reconstructive surgery in patients using HSI. Spectral unmixing, accounting for multiple chromophores, provides sO2 values that are in accordance with physiological expectations in patients with normal functioning microvascularization. Our results suggest that HSI methods that yield reliable spectra are to be preferred, so that the analysis can produce results that are of clinical relevance.


Assuntos
Imageamento Hiperespectral , Cirurgia Plástica , Humanos , Oxigênio , Testa/cirurgia , Saturação de Oxigênio
10.
Intensive Care Med Exp ; 11(1): 12, 2023 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-36929361

RESUMO

OBJECTIVES: Detecting particle flow from the airways by a non-invasive analyzing technique might serve as an additional tool to monitor mechanical ventilation. In the present study, we used a customized particles in exhaled air (PExA) technique, which is an optical particle counter for the monitoring of particle flow in exhaled air. We studied particle flow while increasing and releasing positive end-expiratory pressure (PEEP). The aim of this study was to investigate the impact of different levels of PEEP on particle flow in exhaled air in an experimental setting. We hypothesized that gradually increasing PEEP will reduce the particle flow from the airways and releasing PEEP from a high level to a low level will result in increased particle flow. METHODS: Five fully anesthetized domestic pigs received a gradual increase of PEEP from 5 cmH2O to a maximum of 25 cmH2O during volume-controlled ventilation. The particle count along with vital parameters and ventilator settings were collected continuously and measurements were taken after every increase in PEEP. The particle sizes measured were between 0.41 µm and 4.55 µm. RESULTS: A significant increase in particle count was seen going from all levels of PEEP to release of PEEP. At a PEEP level of 15 cmH2O, there was a median particle count of 282 (154-710) compared to release of PEEP to a level of 5 cmH2O which led to a median particle count of 3754 (2437-10,606) (p < 0.009). A decrease in blood pressure was seen from baseline to all levels of PEEP and significantly so at a PEEP level of 20 cmH2O. CONCLUSIONS: In the present study, a significant increase in particle count was seen on releasing PEEP back to baseline compared to all levels of PEEP, while no changes were seen when gradually increasing PEEP. These findings further explore the significance of changes in particle flow and their part in pathophysiological processes within the lung.

11.
Respir Res ; 23(1): 369, 2022 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-36544145

RESUMO

BACKGROUND: Screening decreases mortality among lung cancer patients but is not widely implemented, thus there is an unmet need for an easily accessible non-invasive method to enable early diagnosis. Particles in exhaled air offer a promising such diagnostic tool. We investigated the validity of a particles in exhaled air device (PExA) to measure the particle flow rate (PFR) and collect exhaled breath particles (EBP) to diagnose primary lung adenocarcinoma (LUAD). METHODS: Seventeen patients listed for resection of LUAD stages IA-IIIA and 18 non-cancer surgical control patients were enrolled. EBP were collected before and after surgery for LUAD, and once for controls. Proteomic analysis was carried out using a proximity extension assay technology. Results were validated in both plasma from the same cohort and with microarray data from healthy lung tissue and LUAD tissue in the GSE10072 dataset. RESULTS: Of the 92 proteins analyzed, levels of five proteins in EBP were significantly higher in the LUAD patients compared to controls. Levels of phospholipid transfer protein (PLTP) and hepatocyte growth factor receptor (MET) decreased in LUAD patients after surgery compared to control patients. PFR was significantly higher in the LUAD cohort at all timepoints compared to the control group. MET in plasma correlated significantly with MET in EBP. CONCLUSION: Collection of EBP and measuring of PFR has never been performed in patients with LUAD. In the present study PFR alone could distinguish between LUAD and patients without LUAD. PLTP and MET were identified as potential biomarkers to evaluate successful tumor excision.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Proteínas de Transferência de Fosfolipídeos , Humanos , Adenocarcinoma de Pulmão/diagnóstico , Adenocarcinoma de Pulmão/metabolismo , Adenocarcinoma de Pulmão/cirurgia , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/cirurgia , Neoplasias Pulmonares/metabolismo , Proteínas de Transferência de Fosfolipídeos/metabolismo , Proteômica , Proteínas Proto-Oncogênicas c-met/metabolismo
12.
Biomedicines ; 10(11)2022 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-36359256

RESUMO

Non-small cell lung cancer (NSCLC) is associated with low survival rates, often due to late diagnosis and lack of personalized medicine. Diagnosing and monitoring NSCLC using blood samples has lately gained interest due to its less invasive nature. In the present study, plasma was collected at three timepoints and analyzed using proximity extension assay technology and quantitative real-time polymerase chain reaction in patients with primary NSCLC stages IA-IIIA undergoing surgery. Results were adjusted for patient demographics, tumor, node, metastasis (TNM) stage, and multiple testing. Major histocompatibility (MHC) class 1 polypeptide-related sequence A/B (MIC-A/B) and tumor necrosis factor ligand superfamily member 6 (FASLG) were significantly increased post-surgery, suggesting radical removal of cancerous cells. Levels of hepatocyte growth factor (HGF) initially increased postoperatively but were later lowered, potentially indicating radical removal of malignant cells. The levels of FASLG in patients who later died or had a relapse of NSCLC were lower at all three timepoints compared to surviving patients without relapse, indicating that FASLG may be used as a prognostic biomarker. The biomarkers were confirmed using microarray data. In conclusion, quantitative proteomics could be used for NSCLC identification but may also provide information on radical surgical removal of NSCLC and post-surgical prognosis.

13.
Photoacoustics ; 27: 100384, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36068803

RESUMO

Photoacoustic (PA) imaging is rapidly emerging as a promising clinical diagnostic tool. One of the main applications of PA imaging is to image vascular networks in humans. This relies on the signal obtained from oxygenated and deoxygenated hemoglobin, which limits imaging of the vessel wall itself. Giant cell arteritis (GCA) is a treatable, but potentially sight- and life-threatening disease, in which the artery wall is infiltrated by leukocytes. Early intervention can prevent complications making prompt diagnosis of importance. Temporal artery biopsy is the gold standard for diagnosing GCA. We present an approach to imaging the temporal artery using multispectral PA imaging. Employing minimally supervised spectral analysis, we produce histology-like images where the artery wall is clearly discernible from the lumen and further differentiate between PA spectra from biopsies diagnosed as GCA- and GCA+ in 77 patients.

14.
Ophthalmic Plast Reconstr Surg ; 38(6): 588-592, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35657677

RESUMO

PURPOSE: The aim of this study was to monitor how the blood perfusion in human upper eyelids is affected during full-thickness blepharotomy. METHODS: Seven eyelids in 5 patients with upper eyelid retraction due to Graves' disease underwent full-thickness blepharotomy. Perfusion was measured using laser speckle contrast imaging in the eyelid margin and in the conjunctival pedicle. RESULTS: Immediately following the procedure, a nonsignificant reduction in perfusion was observed in the skin of the pretarsal eyelid margin, being 66% of the initial value ( p = n.s.). However, a statistically significant decrease in perfusion, to 53% of the initial value ( p < 0.01), was seen in the central pedicle of the conjunctiva. There were no surgical complications such as infection, signs of ischemia, or bleeding. CONCLUSIONS: In this study, eyelid perfusion was mapped during full-thickness blepharotomy for the first time using laser speckle contrast imaging. The results showed that perfusion is sufficiently preserved during surgery, probably due to the rich vascular supply in the periocular region, which may explain the low risk of postoperative complications such as ischemia and infection.


Assuntos
Blefaroplastia , Doença de Graves , Humanos , Blefaroplastia/métodos , Imagem de Contraste de Manchas a Laser , Resultado do Tratamento , Pálpebras/cirurgia , Doença de Graves/cirurgia , Perfusão
15.
Ophthalmic Plast Reconstr Surg ; 38(5): 462-468, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35470293

RESUMO

PURPOSE: Epinephrine is used in local anesthetics to induce vasoconstriction and thus reduce bleeding and prolong the anesthetic effect. Finding the optimal delay between the administration of the anesthetic and skin incision to ensure vasoconstriction and minimize bleeding is important and has recently become the subject of debate. This is the first study to assess blood perfusion and oxygen saturation (sO 2 ) simultaneously in response to a local anesthetic containing epinephrine in human oculoplastic surgery. METHODS: A local anesthetic consisting of lidocaine and epinephrine (20 mg/ml + 12.5 µg/ml) was injected in the eyelids of 9 subjects undergoing blepharoplasty. The perfusion and sO 2 of the eyelids were monitored using laser speckle contrast imaging and hyperspectral imaging, respectively. RESULTS: Laser speckle contrast imaging monitoring showed a decrease in perfusion over time centrally at the site of injection. Half-maximum effect was reached after 34 seconds, and full effect after 115 seconds, determined by exponential fitting. The drop in perfusion decreased gradually further away from the injection site and hypoperfusion was less prominent 4 mm from the injection site, with a spatially dependent half-maximum effect of 231 seconds. Hyperspectral imaging showed only a slight decrease in sO 2 of 11 % at the injection site. CONCLUSIONS: The optimal time delay for skin incision in oculoplastic surgery is approximately 2 minutes after the injection of lidocaine with epinephrine. Longer delay does not lead to a further decrease in perfusion. As sO 2 was only slightly reduced after injection, the results indicate that the use of epinephrine is safe in the periocular region.


Assuntos
Anestésicos Locais , Imagem de Contraste de Manchas a Laser , Método Duplo-Cego , Epinefrina/farmacologia , Humanos , Lidocaína/farmacologia , Vasoconstritores/farmacologia
16.
Biomed Opt Express ; 13(1): 410-425, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35154881

RESUMO

Radical excision of periorbital skin tumors is difficult without sacrificing excessive healthy tissue. Photoacoustic (PA) imaging is an emerging non-invasive biomedical imagi--ng modality that has potential for intraoperative micrographic control of surgical margins. This is the first study to assess the feasibility of PA imaging for the detection of periocular skin cancer. Eleven patients underwent surgical excision of periocular skin cancer, one of which was a malignant melanoma (MM), eight were basal cell carcinomas (BCCs), and two squamous cell carcinomas (SCCs). Six tumors were located in the eyelid, and five in periocular skin. The excised samples, as well as healthy eyelid samples, were scanned with PA imaging postoperatively, using 59 wavelengths in the range 680-970 nm, to generate 3D multispectral images. Spectral unmixing was performed using endmember spectra for oxygenated and deoxygenated Hb, melanin, and collagen, to iden--tify the chromophore composition of tumors and healthy eyelid tissue. After PA scanning, the tumor samples were examined histopathologically using standard hematoxylin and eosin staining. The PA spectra of healthy eyelid tissue were dominated by melanin in the skin, oxygenated and deoxygenated hemoglobin in the orbicularis oculi muscle, and collagen in the tarsal plate. Multiwavelength 3D scanning provided spectral information on the three tumor types. The spectrum from the MM was primarily reconstructed by the endmember melanin, while the SCCs showed contributions primarily from melanin, but also HbR and collagen. BCCs showed contributions from all four endmembers with a predominance of HbO2 and HbR. PA imaging may be used to distinguish different kinds of periocular skin tumors, paving the way for future intraoperative micrographic control.

17.
Acta Anaesthesiol Scand ; 66(4): 483-496, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35014027

RESUMO

BACKGROUND: Primary graft dysfunction (PGD) is still a major complication in patients undergoing lung transplantation (LTx). Much is unknown about the effect of postoperative mechanical ventilation on outcomes, with debate on the best approach to ventilation. AIM/PURPOSE: The goal of this study was to generate hypotheses on the association between postoperative mechanical ventilation settings and allograft size matching in PGD development. METHOD: This is a retrospective study of LTx patients between September 2011 and September 2018 (n = 116). PGD was assessed according to the International Society of Heart and Lung Transplantation (ISHLT) criteria. Data were collected from medical records, including chest x-ray assessments, blood gas analysis, mechanical ventilator parameters and spirometry. RESULTS: Positive end-expiratory pressures (PEEP) of 5 cm H2 O were correlated with lower rates of grade 3 PGD. Graft size was important as tidal volumes calculated according to the recipient yielded greater rates of PGD when low volumes were used, a correlation that was lost when donor metrics were used. CONCLUSION: Our results highlight a need for greater investigation of the role donor characteristics play in determining post-operative ventilation of a lung transplant recipient. The mechanical ventilation settings on postoperative LTx recipients may have an implication for the development of acute graft dysfunction. Severe PGD was associated with the use of a PEEP higher than 5 and lower tidal volumes and oversized lungs were associated with lower long-term mortality. Lack of association between ventilatory settings and survival may point to the importance of other variables than ventilation in the development of PGD.


Assuntos
Transplante de Pulmão , Disfunção Primária do Enxerto , Humanos , Pulmão , Transplante de Pulmão/efeitos adversos , Disfunção Primária do Enxerto/epidemiologia , Disfunção Primária do Enxerto/etiologia , Respiração Artificial/métodos , Estudos Retrospectivos , Fatores de Risco , Transplantados
18.
Ophthalmic Plast Reconstr Surg ; 38(3): 274-279, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34750313

RESUMO

BACKGROUND: The glabellar flap is a common technique for surgical repair after tumor excision in the medial canthal area. However, the outcome may be affected by partial flap necrosis. Little is known about the impact of surgery on blood perfusion and the postoperative course of reperfusion due to the absence of reliable and noninvasive perfusion monitoring techniques. The aim of this study was to use a modern imaging technique to assess blood perfusion in glabellar flaps. METHODS: Glabellar flaps were used to repair medial canthal defects following tumor excision in 7 patients. Blood perfusion was monitored using laser speckle contrast imaging: during surgery, immediately postoperatively (0 weeks), and at follow-up, 1, 3, and 6 weeks after surgery. RESULTS: Perfusion decreased gradually along the length of the flap, and reached a minimum 15 mm from the flap base. Perfusion in the proximal 20 mm of the flap was completely restored after 1 week, while the distal part of the flap was gradually reperfused over 6 weeks. Both the functional and esthetic surgical outcomes were excellent. CONCLUSIONS: The rapid reperfusion of the glabellar flap may be explained by its connection to the vascular network via the flap pedicle. In flaps longer than 20 mm, the distal part can be considered a free skin transplant, and a combination of a glabellar flap and a free skin graft could then be considered.


Assuntos
Carcinoma Basocelular , Neoplasias Palpebrais , Procedimentos de Cirurgia Plástica , Neoplasias Cutâneas , Carcinoma Basocelular/cirurgia , Neoplasias Palpebrais/cirurgia , Pálpebras/cirurgia , Humanos , Imagem de Contraste de Manchas a Laser , Perfusão , Procedimentos de Cirurgia Plástica/métodos , Neoplasias Cutâneas/cirurgia
19.
Ophthalmic Plast Reconstr Surg ; 38(2): 166-169, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34293787

RESUMO

BACKGROUND: The aim of this study was to monitor blood perfusion in human upper eyelid skin flaps and examine how the perfusion is affected by the thickness of the flap. METHODS: Twenty upper eyelids were dissected as part of a blepharoplasty procedure in patients. The medial end of the blepharoplasty flap remained attached to mimic a flap design often used in reconstruction in the periocular area, a myocutaneous flap in which the blood supply follows the fibers of the orbicularis muscle and is thus parallel to the long axis of the flap. The muscle was thereafter dissected from the flap to create a cutaneous flap. Blood perfusion in the 2 types of flaps was compared using laser speckle contrast imaging. RESULTS: Blood perfusion decreased gradually from the base to the tip of all the flaps. Perfusion was significantly higher in the myocutaneous flaps than in the cutaneous flaps (p < 0.0004): 69% in the myocutaneous flaps and 43% in the cutaneous flaps, measured 5 mm from the base. Blood perfusion was preserved to a greater extent distally in the myocutaneous flaps (minimum value seen at 25 mm) than in the cutaneous flaps (minimum seen at 11 mm). CONCLUSIONS: Blood perfusion was better preserved in myocutaneous flaps, including both skin and the orbicularis oculi muscle, than in cutaneous flaps. This may be of clinical interest in patients with poor microcirculation in which a long flap is required for reconstructive surgery.


Assuntos
Blefaroplastia , Retalho Miocutâneo , Procedimentos de Cirurgia Plástica , Blefaroplastia/métodos , Pálpebras/cirurgia , Músculos Faciais/cirurgia , Humanos , Retalho Miocutâneo/cirurgia , Perfusão , Procedimentos de Cirurgia Plástica/métodos
20.
Ophthalmic Plast Reconstr Surg ; 38(6): 522-534, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34919068

RESUMO

PURPOSE: Knowledge of how blood perfusion is affected during and after reconstructive surgery is of great importance to predict the survival of grafts and flaps. When commonly used reconstructive procedures were developed a century ago, they were based on empirical observations of clinical outcome. METHODS: This is a comprehensive literature review that summarizes the current state of knowledge regarding microvascular perfusion monitoring during oculoplastic procedures. RESULTS: Over the years, a number of techniques for perfusion monitoring have been developed as an attempt to be more objective than clinical examination using traditional methods such as observations of skin temperature, turgor, color, smell, and capillary refill time. There are limited publications regarding microvascular perfusion monitoring during reconstructive procedures in the periocular area. Modern laser-based techniques have been attractive due to their noninvasive nature. CONCLUSIONS: Today, modern, noninvasive techniques are available to monitor perfusion during and after surgery. This has increased our knowledge on the perfusion in common oculoplastic surgery procedures. A detailed understanding of how blood perfusion is affected will hopefully allow the improvement of surgical techniques for better clinical outcome.


Assuntos
Oftalmologia , Procedimentos de Cirurgia Plástica , Humanos , Procedimentos de Cirurgia Plástica/métodos , Retalhos Cirúrgicos/irrigação sanguínea , Perfusão
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