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Objective: Conventional two-dimensional ultrasound has been assessed for the non-invasive diagnosis of giant cell arteritis (GCA), but the results are operator dependent, resulting in low sensitivity. Tomographic three-dimensional (3D) ultrasound is a novel technique that enables the objective documentation of vessel geometry. Here, for the first time, its utility is assessed for visualizing temporal arteries. Method: The temporal artery of 14 healthy subjects and three subjects with suspected GCA was examined using tomographic 3D ultrasound. Results: This technique enabled 3D mapping of the architecture of the temporal artery. The inner and outer vessel diameters showed considerable interindividual variability. However, calculation of the vessel wall fraction revealed the combination of vessel wall thickening and lumen narrowing, which may be indicative of GCA. Conclusions: This proof-of-concept study indicates that tomographic 3D ultrasound can be used for objective mapping of the temporal artery. The technique must be evaluated regarding its diagnostic sensitivity in GCA before it can be introduced in clinical practice. [ABSTRACT FROM AUTHOR]

Giant cell arteritis (GCA) is a treatable, but potentially sight- and life-threatening form of systemic vasculitis. Prompt and correct diagnosis is therefore important. Temporal artery biopsy (TAB) is the gold standard for diagnosing GCA, but is associated with risks. There is no reliable non-invasive technique for the diagnosis of GCA. Ultrasound centre frequency shift (CFS) is a novel technique that uses high-frequency ultrasound and the analysis of the centre frequency of the ultrasound pulse, which is dependent on the size of the microstructures in the tissue. This provides an objective measure of the scattering microstructures in the tissue, and thus has the potential to discriminate changes due to disease. The aim of this study was to assess ultrasound CFS as a means of discriminating arteries affected by GCA from healthy arteries. TAB specimens from 68 subjects, 53 female and 15 male, with a mean age of 73 (range 52–87) years, with suspected GCA were examined using ultrasound ex vivo and the CFS was analysed. The temporal arteries were then examined histopathologically. Histopathological examination revealed that 25 of the 68 biopsies of the temporal artery showed inflammatory changes in the vessel wall compatible with GCA. The ultrasound CFS decreased less in TAB-positive than in TAB-negative temporal arteries (p < 0.05). This proof-of-principle study indicates that ultrasound CFS has the potential to detect GCA in temporal arteries. Further technical development will be needed before in vivo examination can be performed and the clinical applicability can be assessed. [ABSTRACT FROM AUTHOR]

Background/aims: Anterior segment ischaemia (ASI) is a rare but serious complication of strabismus surgery, which may be caused by damage to the anterior ciliary arteries that run along the rectus muscles. To avoid ASI, clinical praxis is to operate on a maximum of two rectus muscles at a time. The aim of this study was to perform a detailed study of the contribution of the four ocular rectus muscles to the perfusion of the anterior segment using laser speckle contrast imaging (LSCI)., Methods: The four rectus muscles were successively detached during enucleation in nine patients with suspected uveal melanoma. Perfusion of the anterior segment was monitored with LSCI during the detachment of each of the rectus muscles, and after the ophthalmic artery had been severed., Results: Perfusion of the anterior segment, measured in the paralimbal tissue, decreased gradually as the four rectus muscles were detached, showing a decrease to 98% when the first (lateral rectus) muscle was detached, to 88% when the second (medial rectus), and 69% when the third (inferior rectus) muscles were detached. The decrease was more pronounced and statistically significant when the fourth (superior rectus) muscle was detached (to 28%, p=0.0102)., Conclusion: LSCI is a valuable perfusion monitoring tool, as it has the capability to visualise the gradual decrease in anterior segment perfusion as the rectus muscles are successively detached. Further studies are needed to determine how many rectus muscles can be safely detached during strabismus surgery without risking ASI., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

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.

Background: A dreaded complication of strabismus surgery is anterior segment ischaemia (ASI), caused by damage to the anterior ciliary arteries. To avoid ASI, a maximum of two rectus muscles are operated on at a time. However, these surgical protocols are based on empirical observations of clinical outcome, rather than objective perfusion measurements. There is no method available for perioperative, real-time perfusion measurements during ocular muscle surgery. The aims of this study were to investigate whether laser speckle contrast imaging (LSCI) could be used for such measurements, and to monitor perfusion during strabismus surgery on one or two horizontal rectus muscles., Methods: Forty-four eyes in 44 patients with horizontal strabismus underwent corrective surgery involving medial and/or lateral rectus muscle detachment. Perfusion in the adjacent paralimbal and iris tissue was monitored with LSCI., Results: When the first horizontal rectus muscle was detached perfusion in the adjacent paralimbal tissue decreased by 23% (p<0.0001), and by 12% (p<0.0001) when the second muscle was detached. The iris perfusion decreased by 5% (p<0.05) when the first muscle was detached but showed no significant decrease as the second muscle was cut., Conclusion: This is the first study showing that perfusion of the anterior segment can be monitored non-invasively with LSCI during strabismus surgery. In this cohort, two horizontal rectus muscles were detached with only a small decrease in the anterior segment circulation. Future studies are required for complete mapping of the effect of surgery on multiple ocular muscles on the anterior segment circulation., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Introduction: Groin hernias in women is much less common than in men; it constitutes only 9% of all groin hernia operations. Historically, studies have been performed on men and the results applied to both genders. However, prospectively registered operations within national registers have contributed to new knowledge regarding groin hernias in women. The aim of this paper was to investigate and present a body of literature based upon the Swedish Hernia Register together with recent data from the register's annual report. Patients and Methods: PubMed and Embase were searched for studies based on the Swedish Hernia Register between 1992 and 2023. Based on the initial reading of abstracts, studies that presented results separately for women were selected and read. Recent data were acquired from the 2022 annual report of the Swedish Hernia Register. Results: A total of 73 studies of interest were identified. Of these, 52 included women, but only 19 presented separate results for women. Four themes emerged and were analysed further: emergency surgery and mortality, femoral hernias, the risk of reoperation for recurrence, and chronic pain following female groin hernia repairs. Discussion: Studies from the Swedish Hernia Register clearly describe that both the presentation of hernias and outcomes after repair differ significantly between the two genders. The differences that have been identified over the years have been incorporated into the national guidelines. Register data indicates that the guidelines have been implemented and are fairly well adhered to. As a result, significant improvements in outcomes regarding recurrences have been made for women with groin hernias in Sweden., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Dahlstrand, Melkemichel, Österberg, Montgomery and de la Croix.)

Low anterior resection for rectal cancer often includes a diverting loop-ileostomy to avoid the severe consequences of anastomotic leakage. Reversal of the stoma is often delayed, which can incur health-care costs on different levels. The aim is to, on population basis, determine stoma-related costs, and to investigate habitual and socioeconomic factors associated to the level of cost. Multi-register design with data from the Swedish Rectal Cancer Registry, the National Prescribed Drug Register, Statistics Sweden and cost-administrative data from the National Board of Health and Welfare. Data was gathered for 3564 patients with rectal cancer surgery 2007 to 2013, for 3 years following the surgery. Factors influencing the cost of inpatient care and stoma-related consumables were assessed with linear regression analyses. All monthly costs were higher for females (consumables P  < .001 and in-patient care P  = .031). Post-secondary education ( P  = .003) and younger age ( P  = .020) was associated with a higher cost for consumables while suffering a surgical complication was associated with increased cost for inpatient care ( P  < .001). Patients who had their stoma longer had lower monthly costs (consumables P  < .001 and in-patient care P  < .001). Female gender, longer duration of stoma, young age, and higher education are associated with higher costs for the care of a diverting stoma after rectal cancer surgery. This study does not allow for analyses of causality but the results together with deepened analyses of underlying reasons form a proper basis for decisions in health care planning and allocation of resources. These findings may have implications on the debate of equal care for all., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Drs. Dahlstrand, Gustafsson, Näsvall and Johansson have nothing to disclose. Dr. Gunnarsson reports grants from Region Västerbotten, grants from The Swedish Research Council, grants from VISARE NORR Fund (Northern country councils Regional federation), during the conduct of the study. Dr. Lindforss reports grants from The Swedish Society of Medicine, during the conduct of the study.

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., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc.)

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., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Authors.)

We demonstrate that laser speckle contrast imaging can be used to monitor blood perfusion noninvasively during the detachment of ocular muscles, which may be a valuable tool for reducing the risk of anterior segment ischemia as a complication of strabismus surgery., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

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 HbO 2 and HbR. PA imaging may be used to distinguish different kinds of periocular skin tumors, paving the way for future intraoperative micrographic control., Competing Interests: The authors declare no conflicts of interest., (© 2021 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.)

Purpose: Current hypothesis regarding the mechanism of active tear drainage is based on studies performed ex vivo or under nonphysiological conditions. Novel ultra-high-frequency ultrasound has the advantage of generating images with superior resolution, enabling measurements of low flow in small vessels, and the tracking of tissue motion in real time. The purpose of this study was to investigate the lacrimal drainage system and active drainage using this modality., Methods: The upper lacrimal drainage system was investigated with 40-70 MHz ultrasound in 22 eyes in 13 patients. Irrigation confirmed a lacrimal obstruction in 10 eyes. Motion tracking was used to map movement of the lateral lacrimal sac wall and to measure flow when possible., Results: The anatomy of the upper lacrimal drainage system was mapped in vivo, including the proximal canaliculi, which have not previously been imaged. The lacrimal sac lumen is slit shaped in its resting state but is distended when irrigated or if a nasolacrimal duct obstruction is present. Thus, the healthy lacrimal sac is not a cavity, and the medial retinaculum does not act against a stretched structure. Motion tracking visualized the "lacrimal pump," showing that the direction of motion of the lateral lacrimal sac wall is mainly in the sagittal plane during blinking., Conclusions: Ultra-high-frequency ultrasound allows detailed physiological monitoring of the upper lacrimal drainage system in vivo. Our findings suggest that current theories of active tear drainage need to be reappraised., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2021 The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc.)

Objective: The aim of this study was to investigate whether differences in postoperative outcome exist between open inguinal hernia repairs performed by surgical trainees and those performed by specialist surgeons., Summary of Background Data: Inguinal hernia repair is the prototype educational surgical procedure. The impact of trainee participation on postoperative outcome is still controversial and despite earlier studies no reliable hernia-specific data exist., Methods: The study cohort was based on the Swedish Hernia Register and consisted of 61,161 cases of male patients aged 18 years and older with open anterior mesh repair of a primary inguinal hernia between January 1, 2002, and December 31, 2014. The study cohort was selected to represent the typical trainee procedure in Sweden. Primary outcome measures were reoperation due to hernia recurrence and postoperative 30-day complications., Results: Procedures with longer operating times were at a higher risk for reoperation when performed by supervised trainees [57 to 72 minutes: hazard ratio (HR) 1.55, 99% confidence interval (99% CI) 1.05-2.27] or unsupervised trainees (57 to 72 minutes: HR 1.60, 99% CI 1.18-2.17; >72 minutes: HR 1.72, 99% CI 1.25-2.37). The same was true for specialist and trainee-assisted specialists with operating times <43 minutes (HR 1.63, 99% CI 1.25-2.13; HR 1.58, 99% CI 1.09-2.28). Postoperative 30-day complications were generally associated with longer operating times and occurred at all levels of experience., Conclusion: Trainee participation in open inguinal repair in combination with longer operating time is a risk factor associated with higher reoperation rates. This calls for a more structured supervision of trainees in an assumedly basic procedure., Competing Interests: The authors have no conflicts of interest., (Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: Free skin grafts are frequently used in reconstructive surgery. However, little is known about the course of reperfusion due to the previous lack of reliable perfusion monitoring techniques. The aim of this study was to use state-of-the-art laser speckle contrast imaging to monitor free skin grafts in the periocular area., Methods: Seven patients needing surgery due to tumor removal or cicatricial ectropion in the periocular region underwent reconstructive surgery using free skin grafts from either the contralateral upper eyelid or the upper inner arm. The free skin grafts measured 10-30 mm horizontally and 9-30 mm vertically. Blood perfusion was monitored using laser speckle contrast imaging immediately postoperatively (0 weeks) and at follow-up after 1, 3, and 7 weeks., Results: All grafts were reperfused gradually during healing, the median value being 46% in the central part of the graft after 1 week and 79% after 3 weeks. The grafts were completely reperfused after 7 weeks. No difference was observed in the rate of reperfusion between the center and periphery of the grafts (p = not significant). The cosmetic and functional outcome was excellent in all but 1 patient, who developed ectropion that had to be surgically corrected., Conclusions: Skin grafts in the periorbital area are fully reperfused after 7 weeks. The periocular area is known to be well-vascularized and thus forgiving to reconstructive surgery. Future investigations of the reperfusion of free skin grafts in other parts of the body or in higher-risk populations should be carried out., (Copyright © 2021 The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc.)

Surgical excision followed by histopathological examination is the gold standard for the diagnosis and staging of melanoma. Reoperations and unnecessary removal of healthy tissue could be reduced if non-invasive imaging techniques were available for presurgical tumor delineation. However, no technique has gained widespread clinical use to date due to shallow imaging depth or the absence of functional imaging capability. Photoacoustic (PA) imaging is a novel technology that combines the strengths of optical and ultrasound imaging to reveal the molecular composition of tissue at high resolution. Encouraging results have been obtained from previous animal and human studies on melanoma, but there is still a lack of clinical data. This is the largest study of its kind to date, including 52 melanomas and nevi. 3D multiwavelength PA scanning was performed ex vivo, using 59 excitation wavelengths from 680 nm to 970 nm. Spectral unmixing over this broad wavelength range, accounting for the absorption of several tissue chromophores, provided excellent contrast between healthy tissue and tumor. Combining the results of spectral analysis with spatially resolved information provided a map of the tumor borders in greater detail than previously reported. The tumor dimensions determined with PA imaging were strongly correlated with those determined by histopathological examination for both melanomas and nevi., Competing Interests: The authors declare no conflicts of interest., (© 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement.)

In translation from preclinical to clinical studies using photoacoustic imaging, motion artifacts represent a major issue. In this study the feasibility of an in-house algorithm, referred to as intensity phase tracking (IPT), for regional motion correction of in vivo human photoacoustic (PA) images was demonstrated. The algorithm converts intensity to phase-information and performs 2D phase-tracking on interleaved ultrasound images. The radial artery in eight healthy volunteers was imaged using an ultra-high frequency photoacoustic system. PA images were motion corrected and evaluated based on PA image similarities. Both controlled measurements using a computerized stepping motor and free-hand measurements were evaluated. The results of the controlled measurements show that the tracking corresponded to 97 ± 6% of the actual movement. Overall, the mean square error between PA images decreased by 52 ± 15% and by 43 ± 19% when correcting for controlled- and free-hand induced motions, respectively. The results show that the proposed algorithm could be used for motion correction in photoacoustic imaging in humans., Competing Interests: The authors declare no conflicts of interest., (© 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement.)

Purpose: It is generally believed that large eyelid defects must be repaired using a vascularized flap for 1 lamella, while the other can be a free graft. Recent studies indicate that the pedicle of a tarsoconjunctival flap does not contribute to blood perfusion. The purpose of this study was to explore whether large eyelid defects can be repaired using a free bilamellar eyelid autograft alone., Methods: Ten large upper and lower eyelid defects resulting from tumor excision were reconstructed using bilamellar grafts harvested from the contralateral or opposing eyelid. Revascularization of the flap was monitored during healing using laser speckle contrast imaging, and the surgical outcome was assessed., Results: The functional and cosmetic results were excellent. All grafts survived and there was no tissue necrosis. Only 1 patient underwent revision after 4 days as the sutures came loose. Two patients developed minimal ectropion but needed no reoperation. All patients were satisfied with the surgical results. Perfusion monitoring showed that the grafts were gradually revascularized, exhibiting 50% perfusion after 4 weeks and 90% perfusion after 8 weeks., Conclusions: A free bilamellar eyelid graft appears to be an excellent alternative to the tarsoconjunctival flap procedure in the reconstruction of both upper and lower eyelid defects, especially in patients who cannot tolerate visual axis occlusion or the 2-stage procedure of the conventional staged flap procedure., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2020 The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc.)

Purpose: Photoacoustic (PA) imaging has the potential to become a non-invasive diagnostic tool for giant cell arteritis, as shown in pilot experiments on seven patients undergoing surgery. Here, we present a detailed evaluation of the safety regarding visual function and patient tolerability in healthy subjects, and define the spectral signature in the healthy temporal artery., Methods: Photoacoustic scanning of the temporal artery was performed in 12 healthy subjects using 59 wavelengths (from 680 nm to 970 nm). Visual function was tested before and after the examination. The subjects' experience of the examination was rated on a 0-100 VAS scale. Two- and three-dimensional PA images were generated from the spectra obtained from the artery., Results: Photoacoustic imaging did not affect the best corrected visual acuity, colour vision (tested with Sahlgren's Saturation Test or the Ishihara colour vision test) or the visual field. The level of discomfort was low, and only little heat and light sensation were reported. The spectral signature of the artery wall could be clearly differentiated from those of the subcutaneous tissue and skin. Spectral unmixing provided visualization of the chromophore distribution and overall architecture of the artery., Conclusions: Photoacoustic imaging of the temporal artery is well tolerated and can be performed without any risk to visual function, including the function of the retina and the optic nerve. The spectral signature of the temporal artery is specific, which is promising for future method development., (© 2020 The Authors. Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation.)

Purpose: The aim of this study was to investigate how the blood perfusion in human upper eyelid skin flaps is affected by the length of the flap and the degree of stretching and rotation of the flap., Methods: Twenty-nine upper eyelids were dissected as part of a blepharoplastic procedure in patients. The 1-cm wide proximal end of the flap remains attached, to mimic a random pattern skin flap (hereafter called a "skin flap"). Blood perfusion was measured with laser speckle contrast imaging before and after the flap was stretched with forces of 0.5, 1, and 2 N. The flap was then rotated 90°, and the same tensions were applied., Results: Blood perfusion decreased gradually from the base to the tip of the flap. The flap was only well perfused in the proximal 1 cm (60% at 0.5 cm and 37% at 1.0 cm) and was minimally perfused beyond 2 cm (22% at 2.0 cm). Stretching the nonrotated flaps affected perfusion slightly (decreased to 43% at 0.5 cm). Simply rotating the flaps by 90° had no significant effect on the perfusion. The combination of rotation (90°) and stretching reduced the perfusion to 22% at 2 N, when measured 0.5 cm from the base., Conclusions: Blood perfusion in upper eyelid skin flaps decreases rapidly with distance from the base of the flap. Rotating and stretching the skin flap reduces blood perfusion even further, leading to minimal perfusion in this kind of flap at distances greater than 1.5 cm from the base.

Background: Photoacoustic (PA) imaging is an emerging non-invasive biomedical imaging modality that could potentially be used to determine the borders of basal cell carcinomas (BCC) preoperatively in order to reduce the need for repeated surgery., Methods: Two- and three-dimensional PA images were obtained by scanning BCCs using 59 wavelengths in the range 680-970 nm. Spectral unmixing was performed to visualize the tumor tissue distribution. Spectral signatures from 38 BCCs and healthy tissue were compared ex vivo ., Results and Discussion: The PA spectra could be used to differentiate between BCC and healthy tissue ex vivo ( p < 0.05). Spectral unmixing provided visualization of the overall architecture of the lesion and its border., Conclusion: PA imaging can be used to differentiate between BCC and healthy tissue and can potentially be used to delineate tumors prior to surgical excision., Competing Interests: A conflicting interest exists when professional judgement concerning a primary interest (such as patient’s welfare or the validity of research) may be influenced by a secondary interest (such as financial gain or personal rivalry). It may arise for the authors when they have financial interest that may influence their interpretation of their results or those of others. Examples of potential conflicts of interest include employment, consultancies, stock ownership, honoraria, paid expert testimony, patent applications/registrations, and grants or other funding., (© 2020 The Author(s).)

Cutaneous squamous cell carcinoma (cSCC) is a common skin cancer with metastatic potential. To reduce reoperations due to nonradical excision, there is a need to develop a technique for identification of tumor margins preoperatively. Photoacoustic (PA) imaging is a novel imaging technology that combines the strengths of laser optics and ultrasound. Our aim was to determine the spectral signature of cSCC using PA imaging and to use this signature to visualize tumor architecture and borders. Two-dimensional PA images of 33 cSCCs and surrounding healthy skin were acquired ex vivo, using 59 excitation wavelengths from 680 to 970 nm. The spectral response of the cSCCs was compared to healthy tissue, and the difference was found to be greatest at wavelengths in the range 765 to 960 nm (P < .05). Three-dimensional PA images were constructed from spectra obtained in the y-z plane using a linear stepper motor moving along the x-plane. Spectral unmixing was then performed which provided a clear three-dimensional view of the distribution of tumor masses and their borders., (© 2020 The Authors. Journal of Biophotonics published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Background and Objectives: The eyelids are susceptible to a number of skin cancers, which are challenging to excise radically without sacrificing excessive healthy tissue. Photoacoustic (PA) imaging is an emerging non-invasive biomedical imaging modality that could potentially be used for intraoperative micrographic control of the surgical margins of eyelid tumors. In this study, non-cancerous human eyelid tissue was characterized using PA as a first step in the development of this technique., Study Design/materials and Methods: Twelve full-thickness samples from nine patients were analyzed ex vivo using PA imaging. Two-dimensional PA images were acquired using 59 wavelengths in the range of 680-970 nm to obtain the spectral signatures of the skin, orbicularis oculi muscle, and the tarsal plate. Three-dimensional images were obtained by scanning the tissues using a linear stepping motor. Spectral unmixing was performed to visualize the chromophore distribution., Results: The resulting PA spectra could be used to differentiate between the orbicularis oculi muscle and the other two structures (P < 0.05). The signals from the skin and the tarsal plate were more similar in appearance, probably due to similarities in their molecular composition. Spectral unmixing provided a clear visualization of the overall architecture of the eyelids., Conclusions: PA imaging can be used to differentiate between the orbicularis oculi muscle and the eyelid skin and tarsal plate. The main structures of human eyelids could be visualized in three dimensions using PA imaging. This technique could potentially be used to examine eyelid tumors intraoperatively in the future. However, further studies on tumors in vivo are needed before considering such clinical use. Lasers Surg Med. © 2019 Wiley Periodicals, Inc., (© 2019 Wiley Periodicals, Inc.)

Purpose: Large upper eyelid defects can be repaired by rotational full-thickness lower eyelid flaps. The aim was to measure the blood perfusion in such flaps, and how it is affected by the length of the flaps, and the degree of rotation and stretching., Methods: Nine patients underwent the Quickert procedure for entropion repair in which a full-thickness eyelid flap of approximate width 0.5 cm and length 2 cm was dissected in the lower eyelid. This generates a full-thickness eyelid flap similar to that used to repair large upper eyelid defects. Perfusion was measured using laser speckle contrast imaging, before and after the flap was rotated 90° and 120°, and stretched using forces of 0.5, 1, and 2 N., Results: Blood perfusion decreased gradually from the base to the tip of the flap; being 75% of the reference value 0.5 cm from the base, 63% at 1.0 cm, 55% at 1.5, 23% at 1.75 cm, and 4% at 2.0 cm. Rotating the flaps by 90° or 120° had little effect on the perfusion. Stretching reduced the perfusion from 63% to 32% at 2 N, when measured at 1 cm. The combination of stretching and rotation did not lead to any further decrease., Conclusions: Blood perfusion in lower eyelid rotational flaps seems to be more sensitive to stretching than to rotation. Provided the flap is no longer than 1.5 cm, the perfusion will be greater than 20%, even when rotated, which should be sufficient for adequate survival and healing.

Objectives: An extended-wavelength diffuse reflectance spectroscopy (EWDRS) technique was evaluated for its ability to differentiate between and classify different skin and tissue types in an in vivo pig model., Materials and Methods: EWDRS recordings (450-1550 nm) were made on skin with different degrees of pigmentation as well as on the pig snout and tongue. The recordings were used to train a support vector machine to identify and classify the different skin and tissue types., Results: The resulting EWDRS curves for each skin and tissue type had a unique profile. The support vector machine was able to classify each skin and tissue type with an overall accuracy of 98.2%. The sensitivity and specificity were between 96.4 and 100.0% for all skin and tissue types., Conclusion: EWDRS can be used in vivo to differentiate between different skin and tissue types with good accuracy. Further development of the technique may potentially lead to a novel diagnostic tool for e.g. non-invasive tumor margin delineation., Competing Interests: The authors have declared that no competing interests exist.

Background: A previous study in pigs has shown that the pedicle of the tarsoconjunctival flap does not appear to have adequate blood perfusion. The aim of this study was to monitor perfusion in tarsoconjunctival flaps in patients with large lower eyelid defects resulting from tumor surgery., Methods: The modified Hughes procedure was performed in 13 patients. Blood perfusion was monitored using laser Doppler velocimetry and laser speckle-contrast imaging., Results: Blood flow decreased gradually from the pedicle base to the end of the flap and was 19% at the flap base, 11% in the middle of the flap, and 4% in the distal end of the flap. The flaps survived, and there was no tissue necrosis., Conclusions: Tarsoconjunctival tissue survival does not seem to be dependent on a conjunctival flap. Free tarsoconjunctival grafts or composite grafts might be considered as viable alternatives in reconstruction of major eyelid defects.

Purpose: It has recently been shown that the flap pedicle does not supply blood to a tarsoconjunctival graft in the modified Hughes procedure in patients. This raises questions concerning the rate of revascularization of the free skin graft commonly used to reconstruct the anterior lamella. The aim of this study was, thus, to monitor the course of revascularization in free skin grafts overlying modified Hughes tarsoconjunctival flaps, using laser-based techniques., Methods: Free skin grafts from the upper eyelid or upper arm in 9 patients were used to cover a tarsoconjunctival flap according to the modified Hughes procedure. Blood perfusion was monitored using laser speckle contrast imaging, and vascular reactivity was studied with laser Doppler velocimetry after heating the tissue to 44°C. Measurements were made at the time of surgery (baseline) and at 1, 3, 8, and 16 weeks postoperatively., Results: The gradual increase in perfusion of the free skin grafts during the healing process indicates revascularization. A slight increase in perfusion was seen already after 1 week. Perfusion reached 50% of the baseline after 3 weeks, and complete restoration of perfusion was seen after 8 weeks. The vascular function monitored with heat-induced hyperemia increased in a similar fashion., Conclusions: Full-thickness skin grafts revascularize within 3 to 8 weeks, despite overlying a tarsoconjunctival flap, which has recently been reported to be avascular. This provides further evidence that it should be possible to repair large eyelid defects using free full-thickness eyelid grafts.

The objective was to provide a clinical setup for photoacoustic imaging (PAI) of the temporal artery in humans and to describe the challenges encountered and methods of overcoming them. The temporal artery was examined in seven patients with suspect giant-cell arteritis (GCA), both in vivo and ex vivo, and the results were compared to that of histology. To adapt PAI to the human studies, the transducer was fixed to an adjustable arm to reduce motion artifacts, and a stepping motor was developed to enable 3-D scanning. Risks associated with the use of lasers, ultrasound, and electrical equipment were evaluated by measuring energy levels, and safety precautions were undertaken to prevent injury to the patients and staff. The PAI spectra obtained clearly delineated the artery wall, both in vivo and ex vivo, although the latter was of high quality due to the lack of artifacts. The results could be compared to that of histology. The involved energy levels were found to be below the limits given in regulatory standards. Eye protectors prevented irradiation of the patient's eyes, and visual function after the procedure was found not to be affected. The patients reported no discomfort during the investigations. PAI provides images of the temporal artery wall that may be used for the future diagnosis of GCA in humans. The technique could be further refined by addressing the specific problems of motion artifacts and interference from blood and other chromophores. This study paves the way for other clinical applications of PAI.

Objective: Based on clinical experience gained over many years, the maximal haemostatic effect following administration of local anaesthetics containing epinephrine is generally believed to occur within 10 min. Surprisingly, it was found in a recent study, in which bleeding was quantified intraoperatively, that maximal haemostasis did not occur until 30 min. If this is indeed the case, then it would be necessary to extend the preoperative waiting time to minimize perioperative bleeding.We have carried out a carefully controlled study on the time delay between administration of a local anaesthetic containing epinephrine and maximal haemostasis in a surgical setting., Methods: Lidocaine 20 mg/ml (2%) or lidocaine + epinephrine 12.5 µg/ml (1:80,000) was injected into the skin of eight pig flanks. Bleeding was induced after 3, 5, 7, 15 and 30 min by making a 10 mm incision at each injection site. Blood was collected for 1 min and weighed., Results: A gradual reduction in bleeding was observed, with maximal reduction after only 7 min (54%, p  < 0.05, 95% CI: 44-64%). No further significant reduction in bleeding was observed (62% at 15 and 66% at 30 min, p  = n.s. compared to 7 min)., Conclusions: Maximal haemostatic effect in the current setting was observed within 7 min of injection of lidocaine with epinephrine. This is in good agreement with previous empirical findings, and we see no reason to prolong the preoperative waiting time., (© 2018 The Authors.)

Background: The aim of this study was to identify risk factors for an adverse event, i.e. early surgical complication, need for ICU care and readmission, following ventral hernia repair. Our hypothesis was that there is an association between an increased complication rate following ventral hernia repair and specific factors, including hernia size, BMI > 35, concomitant bowel surgery, ASA-class, age, gender and method of hernia repair., Methods: Data from a hernia database with prospectively entered data on 408 patients operated for ventral hernia between 2007 and 2014 at two Swedish university hospitals were analysed. A 3-month follow-up of complications, need for intensive care and readmission, was performed by reviewing the medical records., Results: Eighty-one of 408 patients (20%) had a registered complication. Fifty-eight (14%) of these were classed as Clavien I-IIIa, and in 19 cases a Clavien IIIb-IV complication was reported. Large hernia size was associated with increased risk for early complication. A Kendall Tau test analysis revealed a proportional relationship between hernia size and modified Clavien outcome class (p < 0.001). Morbid obesity, ASA-class, method, hernia recurrence, age and concomitant bowel surgery were not statistically significant predictors of adverse events., Conclusions: Assessment of hernia aperture size is of great importance in the preoperative evaluation of ventral hernia patients to consider risk for post-operative complications. These results suggest a careful attitude when applying watchful waiting concepts and when postponing hernia surgery to achieve weight loss. A delaying attitude may result in increased risk of complications caused by increasing hernia size.