Estimation of Hemi-Abdominal-Based Free Flap Weight Using Two Computed Tomography-Derived Measurements

2021 ◽  
Author(s):  
Nicolas Greige ◽  
Bryce Liu ◽  
David Nash ◽  
Katie E. Weichman ◽  
Joseph A. Ricci
Keyword(s):  
Computed Tomography ◽  
Breast Reconstruction ◽  
Free Flap ◽  
Subcutaneous Tissue ◽  
Free Tissue Transfer ◽  
Absolute Error ◽  
Estimation Methods ◽  
Weight Estimation ◽  
Estimation Model ◽  
Split Sample

Abstract Background Accurate flap weight estimation is crucial for preoperative planning in microsurgical breast reconstruction; however, current flap weight estimation methods are time consuming. It was our objective to develop a parsimonious and accurate formula for the estimation of abdominal-based free flap weight. Methods Patients who underwent hemi-abdominal-based free tissue transfer for breast reconstruction at a single institution were retrospectively reviewed. Subcutaneous tissue thicknesses were measured on axial computed tomography angiograms at several predetermined points. Multivariable linear regression was used to generate the parsimonious flap weight estimation model. Split-sample validation was used to for internal validation. Results A total of 132 patients (196 flaps) were analyzed, with a mean body mass index of 31.2 ± 4.0 kg/m2 (range: 22.6–40.7). The mean intraoperative flap weight was 990 ± 344 g (range: 368–2,808). The full predictive model (R 2 = 0.68) estimated flap weight using the Eq. 91.3x + 36.4y + 6.2z – 1030.0, where x is subcutaneous tissue thickness (cm) 5 cm lateral to midline at the level of the anterior superior iliac spine (ASIS), y is distance (cm) between the skin overlying each ASIS, and z is patient weight (kg). Two-thirds split-sample validation was performed using 131 flaps to build a model and the remaining 65 flaps for validation. Upon validation, we observed a median percent error of 10.2% (interquartile range [IQR]: 4.5–18.5) and a median absolute error of 108.6 g (IQR: 45.9–170.7). Conclusion We developed and internally validated a simple and accurate formula for the preoperative estimation of hemi-abdominal-based free flap weight for breast reconstruction.

scholarly journals Computed tomography angiographic study of internal mammary perforators and their use as recipient vessels for free tissue transfer in breast reconstruction

2017 ◽  
Vol 50 (01) ◽  
pp. 050-055
Author(s):  
Aditya V. Kanoi ◽  
Karnav B. Panchal ◽  
Saugata Sen ◽  
Gautam Biswas
Keyword(s):  
Computed Tomography ◽  
Breast Reconstruction ◽  
Free Flap ◽  
Free Tissue Transfer ◽  
Tissue Transfer ◽  
Free Flap Transfer ◽  
Internal Mammary ◽  
Multiple Variables ◽  
The Right ◽  
Artery Perforator

ABSTRACT Context: The internal mammary artery perforator vessels (IMPV) as a recipient in free flap breast reconstruction offer advantages over the more commonly used thoracodorsal vessels and the internal mammary vessels (IMV). Aims: This study was designed to assess the anatomical consistency of the IMPV and the suitability of these vessels for use as recipients in free flap breast reconstruction. Patients and Methods: Data from ten randomly selected female patients who did not have any chest wall or breast pathology but had undergone a computed tomography angiography (CTA) for unrelated diagnostic reasons from April 2013 to October 2013 were analysed. Retrospective data of seven patients who had undergone mastectomy for breast cancer and had been primarily reconstructed with a deep inferior epigastric artery perforator free flap transfer using the IMPV as recipient vessels were studied. Results: The CTA findings showed that the internal mammary perforator was consistently present in all cases bilaterally. In all cases, the dominant perforator arose from the upper four intercostal spaces (ICS) with the majority (55%) arising from the 2nd ICS. The mean distance of the perforators from the sternal border at the level of pectoralis muscle surface on the right side was 1.86 cm (range: 0.9–2.5 cm) with a mode value of 1.9 cm. On the left side, a mean of 1.77 cm (range: 1.5–2.1 cm) and a mode value of 1.7 cm were observed. Mean perforator artery diameters on the right and left sides were 2.2 mm and 2.4 mm, respectively. Conclusions: Though the internal mammary perforators are anatomically consistent, their use as recipients in free tissue transfer for breast reconstruction eventually rests on multiple variables.

Estimation of Profunda Artery Perforator Flap Weight Using Preoperative Computed Tomography Angiography

2020 ◽  
Vol 36 (09) ◽  
pp. 645-650
Author(s):  
Nicolas Greige ◽  
David Nash ◽  
Ara A. Salibian ◽  
Steven M. Sultan ◽  
Joseph A. Ricci ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Breast Reconstruction ◽  
Computed Tomography Angiography ◽  
Subcutaneous Tissue ◽  
Perforator Flap ◽  
Biceps Femoris ◽  
Accurate Estimation ◽  
Parsimonious Model ◽  
Artery Perforator ◽  
Gluteal Fold

Abstract Background Given the relatively small size of thigh-based flaps and the possible necessity for a multiflap reconstruction, it is imperative to arrive at an accurate estimation of flap weight during preoperative planning. It was our objective to develop a novel technique for the preoperative estimation of profunda artery perforator (PAP) flap weight. Methods All patients that underwent transverse PAP flap breast reconstruction at two institutions were retrospectively reviewed. Subcutaneous tissue thicknesses were measured on axial computed tomography angiography scans at several predetermined points. The distance from the inferior gluteal crease to the PAP was also recorded. Linear regression was used to estimate flap weight. Results A total of 18 patients (32 flaps) were analyzed. The median intraoperative flap weight was 299 g (interquartile range [IQR]: 235–408). The parsimonious model (R 2 = 0.80) estimated flap weight using the Eq. 77.9x + 33.8y + 43.4z – 254.3, where x is subcutaneous tissue thickness (cm) at the lateral border of long head of the biceps femoris at a level 4.5 cm caudal to the inferior gluteal fold, y is distance (cm) from the inferior gluteal fold to the dominant PAP, and z has a value of 1 if the patient was scanned in the supine position or 0 if prone. The aforementioned formula yielded a median estimated flap weight of 305 g (IQR: 234–402) and a median percent error of 10.5% (IQR: 6.1–16.2). Conclusion The authors demonstrate a simple and accurate formula for the preoperative estimation of transverse PAP flap weight for breast reconstruction.

scholarly journals Free Tissue Breast Reconstruction

2019 ◽  
Vol 33 (01) ◽  
pp. 059-066 ◽  
Author(s):  
Rami Dibbs ◽  
Jeff Trost ◽  
Valerie DeGregorio ◽  
Shayan Izaddoost
Keyword(s):  
Breast Reconstruction ◽  
Free Flap ◽  
Donor Site ◽  
Perforator Flap ◽  
Free Tissue Transfer ◽  
Donor Site Morbidity ◽  
Fat Grafting ◽  
Microsurgical Technique ◽  
Deep Inferior Epigastric Perforator ◽  
Aesthetic Breast

AbstractFree tissue transfer serves as a modern workhorse for breast reconstruction. Advancements in microsurgical technique have allowed for the development of free flap procedures that produce an aesthetic breast while minimizing donor site morbidity. Here, the authors review the use of different free flap procedures for breast reconstruction with a focus on the preferred and most commonly used flap, the deep inferior epigastric perforator flap. Each flap has its advantages and drawbacks, and certain patient risk factors increase postoperative complications. Other techniques of breast reconstruction including pedicled flaps and adjunctive fat grafting are also briefly discussed.

Tissue Oximetry Readings Accurately Predict Late Complications in Patients Undergoing Free Flap Breast Reconstruction: Exploring the Optimal Cut Point Value

2020 ◽  
Vol 36 (07) ◽  
pp. 534-540 ◽  
Author(s):  
Noah Saad ◽  
Howard Wang ◽  
Efstathios Karamanos
Keyword(s):  
Breast Reconstruction ◽  
Free Flap ◽  
Free Tissue Transfer ◽  
Wound Dehiscence ◽  
The United States ◽  
Late Complications ◽  
Wound Complications ◽  
The Mean ◽  
Initial Reading ◽  
Tissue Oximetry

Abstract Background The use of tissue oximetry for monitoring following free tissue transfer has become a common practice across the United States to facilitate early detection of poor flap perfusion in the postoperative setting. There is no consensus on the optimal value, below which there is a higher chance of wound complications in patients undergoing free flap breast reconstruction. Methods Patients undergoing free flap breast reconstruction from 2015 to 2018 were retrospectively reviewed. Patients who returned to the operating room for a revision of the anastomosis were excluded from analysis. Patients were divided in two groups based on the development of late complications. Those were defined as fat necrosis, wound dehiscence, or distal flap ischemia/necrosis that developed after discharge from the hospital. Mean percutaneous oximetry readings of the first 24 hours were recorded and the mean change from the initial reading was calculated. The correlation between tissue oximetry change and development of complications was explored. Results A total of 120 patients were identified. The mean age was 53, while the mean body mass index was 33. A total of 38 patients developed late wound complication. History of smoking, diabetes mellitus, neoadjuvant radiation therapy, and the mean change of the tissue oximetry reading were identified as independent predictors of wound complications. The absolute number of the tissue oximetry reading did not predict late complications. A multivariate analysis revealed that patients who experienced a mean decrease < 15% from the initial reading during the first 24 hours were significantly more likely to develop late flap-related wound complications. Conclusion In patients undergoing free tissue breast reconstruction, tissue oximetry readings do not predict late wound complications. However, the mean change at 24 hours from the initial reading does. A decrease of <15% in tissue perfusion was associated with a significant increase in the probability of developing flap-related wound complications.

scholarly journals Multi-Scene Building Height Estimation Method Based on Shadow in High Resolution Imagery

2021 ◽  
Vol 13 (15) ◽  
pp. 2862
Author(s):  
Yakun Xie ◽  
Dejun Feng ◽  
Sifan Xiong ◽  
Jun Zhu ◽  
Yangge Liu
Keyword(s):  
Remote Sensing ◽  
High Resolution ◽  
Estimation Method ◽  
Absolute Error ◽  
Large Error ◽  
Estimation Methods ◽  
Height Estimation ◽  
Building Height ◽  
Remote Sensing Imagery ◽  
High Resolution Imagery

Accurately building height estimation from remote sensing imagery is an important and challenging task. However, the existing shadow-based building height estimation methods have large errors due to the complex environment in remote sensing imagery. In this paper, we propose a multi-scene building height estimation method based on shadow in high resolution imagery. First, the shadow of building is classified and described by analyzing the features of building shadow in remote sensing imagery. Second, a variety of shadow-based building height estimation models is established in different scenes. In addition, a method of shadow regularization extraction is proposed, which can solve the problem of mutual adhesion shadows in dense building areas effectively. Finally, we propose a method for shadow length calculation combines with the fish net and the pauta criterion, which means that the large error caused by the complex shape of building shadow can be avoided. Multi-scene areas are selected for experimental analysis to prove the validity of our method. The experiment results show that the accuracy rate is as high as 96% within 2 m of absolute error of our method. In addition, we compared our proposed approach with the existing methods, and the results show that the absolute error of our method are reduced by 1.24 m-3.76 m, which can achieve high-precision estimation of building height.

scholarly journals Comparison of paediatric weight estimation methods at a tertiary hospital in Ghana

2021 ◽  
Vol 11 (2) ◽  
pp. 252-257
Author(s):  
Rafiuk Cosmos Yakubu ◽  
Samuel Blay Nguah ◽  
Nedda Ayi-bisah
Keyword(s):  
Tertiary Hospital ◽  
Estimation Methods ◽  
Weight Estimation

scholarly journals Continuous Blood Pressure Estimation Using Exclusively Photopletysmography by LSTM-Based Signal-to-Signal Translation

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 2952
Author(s):  
Latifa Nabila Harfiya ◽  
Ching-Chun Chang ◽  
Yung-Hui Li
Keyword(s):  
Blood Pressure ◽  
Absolute Error ◽  
Estimation Methods ◽  
British Hypertension Society ◽  
Arterial Blood ◽  
Proposed Model ◽  
Pressure Estimation ◽  
Effective Signal ◽  
Blood Pressure Estimation ◽  
Continuous Blood Pressure

Monitoring continuous BP signal is an important issue, because blood pressure (BP) varies over days, minutes, or even seconds for short-term cases. Most of photoplethysmography (PPG)-based BP estimation methods are susceptible to noise and only provides systolic blood pressure (SBP) and diastolic blood pressure (DBP) prediction. Here, instead of estimating a discrete value, we focus on different perspectives to estimate the whole waveform of BP. We propose a novel deep learning model to learn how to perform signal-to-signal translation from PPG to arterial blood pressure (ABP). Furthermore, using a raw PPG signal only as the input, the output of the proposed model is a continuous ABP signal. Based on the translated ABP signal, we extract the SBP and DBP values accordingly to ease the comparative evaluation. Our prediction results achieve average absolute error under 5 mmHg, with 70% confidence for SBP and 95% confidence for DBP without complex feature engineering. These results fulfill the standard from Association for the Advancement of Medical Instrumentation (AAMI) and the British Hypertension Society (BHS) with grade A. From the results, we believe that our model is applicable and potentially boosts the accuracy of an effective signal-to-signal continuous blood pressure estimation.

Spleen measurements with reference to cause of death and spleen weight estimation: A study on postmortem computed tomography

2019 ◽  
Vol 18 ◽  
pp. 24-31
Author(s):  
Vasiliki Chatzaraki ◽  
Janette Verster ◽  
Carlo Tappero ◽  
Michael J Thali ◽  
Wolf Schweitzer ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Cause Of Death ◽  
Spleen Weight ◽  
Postmortem Computed Tomography ◽  
Weight Estimation

Cerebral mycetoma with cranial osteomyelitis

2008 ◽  
Vol 1 (6) ◽  
pp. 493-495 ◽  
Author(s):  
Vamseemohan Beeram ◽  
Sundaram Challa ◽  
Prasad Vannemreddy
Keyword(s):  
Computed Tomography ◽  
Cerebral Cortex ◽  
Parietal Cortex ◽  
Subcutaneous Tissue ◽  
Young Male ◽  
Ct Scanning ◽  
Parietal Bone ◽  
Total Excision ◽  
Farm Laborer ◽  
Left Parietal Cortex

✓ Craniocerebral maduromycetoma is extremely rare. The authors describe a case of maduromycetoma involving the left parietal cortex, bone, and subcutaneous tissue in a young male farm laborer who presented with left parietal scalp swelling that had progressed into a relentlessly discharging sinus. Computed tomography (CT) scanning of his brain revealed osteomyelitis of the parietal bone with an underlying homogeneously enhancing tumor. Intraoperatively, the mass was revealed to be a black lesion involving the bone, dura mater, and underlying cerebral cortex. It was friable and separated from the surrounding brain by a thick gliotic scar. Gross-total excision was performed, and the patient was placed on a 6-week regimen of itraconazole. To the authors' knowledge, this is the first instance of cerebral mycetoma with CT findings reported in the literature.

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