Modern imaging techniques are an essential component of preoperative planning in plastic and reco... more Modern imaging techniques are an essential component of preoperative planning in plastic and reconstructive surgery. However, conventional modalities, including three-dimensional (3D) reconstructions, are limited by their representation on 2D workstations. 3D printing, also known as rapid prototyping or additive manufacturing, was once the province of industry to fabricate models from a computer-aided design (CAD) in a layer-by-layer manner. The early adopters in clinical practice have embraced the medical imaging-guided 3D-printed biomodels for their ability to provide tactile feedback and a superior appreciation of visuospatial relationship between anatomical structures. With increasing accessibility, investigators are able to convert standard imaging data into a CAD file using various 3D reconstruction softwares and ultimately fabricate 3D models using 3D printing techniques, such as stereolithography, multijet modeling, selective laser sintering, binder jet technique, and fused ...
Breast reconstruction plays an integral role in the holistic management of breast cancer, with as... more Breast reconstruction plays an integral role in the holistic management of breast cancer, with assessment of breast volume, shape, and projection vital in planning breast reconstruction surgery. Current practice includes two-dimensional (2D) photography and visual estimation in selecting ideal volume and shape of breast implants or soft-tissue flaps. Other objective quantitative means of calculating breast volume have been reported, such as direct anthropomorphic measurements or three-dimensional (3D) photography, but none have proven reliably accurate. We describe a novel approach to volumetric analysis of the breast, through the creation of a haptic, tactile model, or 3D print of scan data. This approach comprises use of a single computed tomography (CT) or magnetic resonance imaging (MRI) scan for volumetric analysis, which we use to compare to simpler estimation techniques, create software-generated 3D reconstructions, calculate, and visualize volume differences, and produce bio...
Background Locally advanced breast cancer (LABC) and chest wall osteoradionecrosis (ORN) often re... more Background Locally advanced breast cancer (LABC) and chest wall osteoradionecrosis (ORN) often require extensive and composite tissue resection, including muscles, ribs, pleura, and lung parenchyma. As such, these cases necessitate complex reconstructive procedures for skeletal chest wall reconstruction and soft tissue resurfacing of extensive defects. Traditional local and regional flaps are often inadequate, and many such cases are prospectively labeled "unresectable." Methods We report a single-center experience with the microsurgical reconstruction of such defects over a 5-year period. Between 2007 and 2011, 1,077 microvascular reconstructive cases following breast cancer resection were performed, of which 26 cases comprised LABC or ORN requiring reconstruction. Surgical indications, defect parameters, choice of reconstruction, and outcomes were assessed. Results Thirty free flap microsurgical reconstructions were undertaken in 26 cases, with a 96.2% flap survival rate. Complications were low, and mean hospital stay was 8.7 days. An algorithmic approach to management is presented. Conclusion Wide resection and microvascular free tissue transfer provide versatile solutions for the reconstruction of extensive chest wall defects. With good reported perioperative outcomes even in advanced cases, surgical resection of LABC may offer a useful approach in difficult and/or palliative cases.
Modern imaging techniques are an essential component of preoperative planning in plastic and reco... more Modern imaging techniques are an essential component of preoperative planning in plastic and reconstructive surgery. However, conventional modalities, including three-dimensional (3D) reconstructions, are limited by their representation on 2D workstations. 3D printing, also known as rapid prototyping or additive manufacturing, was once the province of industry to fabricate models from a computer-aided design (CAD) in a layer-by-layer manner. The early adopters in clinical practice have embraced the medical imaging-guided 3D-printed biomodels for their ability to provide tactile feedback and a superior appreciation of visuospatial relationship between anatomical structures. With increasing accessibility, investigators are able to convert standard imaging data into a CAD file using various 3D reconstruction softwares and ultimately fabricate 3D models using 3D printing techniques, such as stereolithography, multijet modeling, selective laser sintering, binder jet technique, and fused ...
 Various reports suggest the augmentation of venous drainage through performing two venous anasto... more  Various reports suggest the augmentation of venous drainage through performing two venous anastomoses as a means of reducing the rate of thrombosis in free flap surgery. However, some suggest dual venous drainage may actually reduce venous blood flow velocity causing a potential risk for thrombosis.   On the basis of the Preferred Reporting Items for Systematics Reviews and Meta-analysis statement, a systematic search was conducted using PubMed and Medline databases. A total of 12,190 articles relating to "free flaps" and "one versus two venous anastomoses" were found between January 1992 and November 2012. Of the 12,190 articles, 23 studies were included in a meta-analysis performed using STATA 11.2 (StrataCorp, College Station, TX). Studies with case control groups for both single and double venous anastomoses and clearly defined results for flap failure and venous thrombosis were included. 95% confidence interval (CI) were calculated for each study and pooled...
Computed tomographic (CT) colonography (or 'virtual' colonoscopy) has become an increasin... more Computed tomographic (CT) colonography (or 'virtual' colonoscopy) has become an increasingly popular tool for colorectal cancer screening. Colonic perforation, an uncommon complication, is a risk that has not been widely reported. A systematic review of the literature was undertaken to identify all reported risk factors for colonic perforation following CT colonography. In addition, a retrospective multicentre study was undertaken, evaluating all CT colonographies in 10 major metropolitan tertiary referral centres. All colonic perforations were assessed for risk factors. A range of 'patient'-related and 'procedure'-related risk factors were identified in the literature. Among 3458 CT colonographies, there were two cases of colonic perforation contributing to an incidence of perforation of 0.06%. There was no statistical correlation between the incidence of perforation and institutional experience (P = 0.66). Risk factors common to both cases and the literatur...
The management of papillary lesions of the breast diagnosed on core needle biopsy is highly conte... more The management of papillary lesions of the breast diagnosed on core needle biopsy is highly contentious. Papillary lesions are epithelial proliferations of breast tissue and are on a continuum of mutations with atypical hyperplastic lesions and in situ carcinoma. With the current literature suggesting that excisional biopsy of papillary lesions might not be required, we discuss a unique case that suggests otherwise. We present a 21-year-old woman with multiple papillary lesions on core biopsy of a breast lesion, and a subsequent excisional biopsy revealing extensive in situ carcinoma of the breast. This finding necessitated total mastectomy. This unique case highlights that core biopsy specimens are unable to effectively exclude adjacent in situ carcinoma and suggests that papillary lesions diagnosed on core needle biopsy require excisional biopsy.
Pediatric low-grade gliomas comprise a diverse range of central nervous system tumors, sharing th... more Pediatric low-grade gliomas comprise a diverse range of central nervous system tumors, sharing the usual course of a slow progression in growth. In individual cases however, the natural history can be variable, and rarely spontaneous regression has been described. This paper describes factors associated with spontaneous regression. A literature review was performed to identify factors associated with spontaneous regression. A unique case is described to contribute to the findings. Low-grade gliomas occurring in association with neurofibromatosis are more likely to spontaneously regress. Only 14 cases of spontaneous regression of low-grade gliomas in patients without neurofibromatosis have been described, and of these, the vast majority regress in association with optic chiasm gliomas. We describe the first documented case of spontaneous regression of a temporal lobe pilocytic astrocytoma in a patient without neurofibromatosis. Spontaneous regression of low-grade gliomas can occur for tumors in a diversity of anatomical locations, at varying ages and in both sexes. This may have implications for management. As such, spontaneous tumor regression is an important outcome to be considered for pediatric low-grade gliomas and pilocytic astrocytomas.
The use of contrast lymphangiography is a relatively new technique in lymphatic anatomical resear... more The use of contrast lymphangiography is a relatively new technique in lymphatic anatomical research, employed as a tool for evaluating lymphatic anatomy in fresh cadaveric specimens. With the use of microsurgical techniques to cannulate lymphatics, contrast media can enable the use of lymphangiography for evaluating lymphatic anatomy. However, the ability to cannulate lymphatics with diameters that are less than the smallest commercially available needles has been a significant limitation, and indeed a challenge. The smallest commercially available hypodermic needles have been 30-gauge needles, with 0.3 mm outer diameters. The lymphatics for cannulation in our studies are of the order of 0.1 mm, and other options have been required. We describe a novel technique for cannulating lymphatic vessels, creating a modified glass hypodermic needle. We have shown that these glass needles can be made with accuracy to diameters as low as 0.01 mm. Although 0.1 mm glass needles are the more commonly utilized in most dissections, we can now accurately create these glass needles to any caliber between 0.01 mm and 0.1 mm, based on the predicted lymphatic anatomy.
Nipple malformations are common congenital or acquired conditions that can have tremendous cosmet... more Nipple malformations are common congenital or acquired conditions that can have tremendous cosmetic, psychological, breast-feeding, sexual, and hygienic ramifications. Ideal reconstruction of the nipple-areola complex (NAC) requires symmetry in position, size, shape, texture, pigmentation, and permanent projection, and although many technical descriptions of NAC reconstruction exist in the medical literature, there are insufficient data presented to accurately compare outcomes. The current article comprises a thorough review of the literature, exploring the techniques described for NAC reconstruction, comparing reported outcomes and complications, and providing an evidence-based approach to NAC reconstruction. The findings of the review suggest that evidence regarding surgical correction of nipple deformity and complete NAC reconstruction is lacking, and loss of nipple projection over time is a pervasive problem common to all flap techniques. A combination of a single pedicle local flap with tattooing for complete NAC reconstruction is currently the most supported method; however, data concerning which type of reconstruction is best suited to immediate versus delayed and type of breast mound remain to be examined.
Modern imaging techniques are an essential component of preoperative planning in plastic and reco... more Modern imaging techniques are an essential component of preoperative planning in plastic and reconstructive surgery. However, conventional modalities, including three-dimensional (3D) reconstructions, are limited by their representation on 2D workstations. 3D printing, also known as rapid prototyping or additive manufacturing, was once the province of industry to fabricate models from a computer-aided design (CAD) in a layer-by-layer manner. The early adopters in clinical practice have embraced the medical imaging-guided 3D-printed biomodels for their ability to provide tactile feedback and a superior appreciation of visuospatial relationship between anatomical structures. With increasing accessibility, investigators are able to convert standard imaging data into a CAD file using various 3D reconstruction softwares and ultimately fabricate 3D models using 3D printing techniques, such as stereolithography, multijet modeling, selective laser sintering, binder jet technique, and fused ...
Breast reconstruction plays an integral role in the holistic management of breast cancer, with as... more Breast reconstruction plays an integral role in the holistic management of breast cancer, with assessment of breast volume, shape, and projection vital in planning breast reconstruction surgery. Current practice includes two-dimensional (2D) photography and visual estimation in selecting ideal volume and shape of breast implants or soft-tissue flaps. Other objective quantitative means of calculating breast volume have been reported, such as direct anthropomorphic measurements or three-dimensional (3D) photography, but none have proven reliably accurate. We describe a novel approach to volumetric analysis of the breast, through the creation of a haptic, tactile model, or 3D print of scan data. This approach comprises use of a single computed tomography (CT) or magnetic resonance imaging (MRI) scan for volumetric analysis, which we use to compare to simpler estimation techniques, create software-generated 3D reconstructions, calculate, and visualize volume differences, and produce bio...
Background Locally advanced breast cancer (LABC) and chest wall osteoradionecrosis (ORN) often re... more Background Locally advanced breast cancer (LABC) and chest wall osteoradionecrosis (ORN) often require extensive and composite tissue resection, including muscles, ribs, pleura, and lung parenchyma. As such, these cases necessitate complex reconstructive procedures for skeletal chest wall reconstruction and soft tissue resurfacing of extensive defects. Traditional local and regional flaps are often inadequate, and many such cases are prospectively labeled "unresectable." Methods We report a single-center experience with the microsurgical reconstruction of such defects over a 5-year period. Between 2007 and 2011, 1,077 microvascular reconstructive cases following breast cancer resection were performed, of which 26 cases comprised LABC or ORN requiring reconstruction. Surgical indications, defect parameters, choice of reconstruction, and outcomes were assessed. Results Thirty free flap microsurgical reconstructions were undertaken in 26 cases, with a 96.2% flap survival rate. Complications were low, and mean hospital stay was 8.7 days. An algorithmic approach to management is presented. Conclusion Wide resection and microvascular free tissue transfer provide versatile solutions for the reconstruction of extensive chest wall defects. With good reported perioperative outcomes even in advanced cases, surgical resection of LABC may offer a useful approach in difficult and/or palliative cases.
Modern imaging techniques are an essential component of preoperative planning in plastic and reco... more Modern imaging techniques are an essential component of preoperative planning in plastic and reconstructive surgery. However, conventional modalities, including three-dimensional (3D) reconstructions, are limited by their representation on 2D workstations. 3D printing, also known as rapid prototyping or additive manufacturing, was once the province of industry to fabricate models from a computer-aided design (CAD) in a layer-by-layer manner. The early adopters in clinical practice have embraced the medical imaging-guided 3D-printed biomodels for their ability to provide tactile feedback and a superior appreciation of visuospatial relationship between anatomical structures. With increasing accessibility, investigators are able to convert standard imaging data into a CAD file using various 3D reconstruction softwares and ultimately fabricate 3D models using 3D printing techniques, such as stereolithography, multijet modeling, selective laser sintering, binder jet technique, and fused ...
 Various reports suggest the augmentation of venous drainage through performing two venous anasto... more  Various reports suggest the augmentation of venous drainage through performing two venous anastomoses as a means of reducing the rate of thrombosis in free flap surgery. However, some suggest dual venous drainage may actually reduce venous blood flow velocity causing a potential risk for thrombosis.   On the basis of the Preferred Reporting Items for Systematics Reviews and Meta-analysis statement, a systematic search was conducted using PubMed and Medline databases. A total of 12,190 articles relating to "free flaps" and "one versus two venous anastomoses" were found between January 1992 and November 2012. Of the 12,190 articles, 23 studies were included in a meta-analysis performed using STATA 11.2 (StrataCorp, College Station, TX). Studies with case control groups for both single and double venous anastomoses and clearly defined results for flap failure and venous thrombosis were included. 95% confidence interval (CI) were calculated for each study and pooled...
Computed tomographic (CT) colonography (or 'virtual' colonoscopy) has become an increasin... more Computed tomographic (CT) colonography (or 'virtual' colonoscopy) has become an increasingly popular tool for colorectal cancer screening. Colonic perforation, an uncommon complication, is a risk that has not been widely reported. A systematic review of the literature was undertaken to identify all reported risk factors for colonic perforation following CT colonography. In addition, a retrospective multicentre study was undertaken, evaluating all CT colonographies in 10 major metropolitan tertiary referral centres. All colonic perforations were assessed for risk factors. A range of 'patient'-related and 'procedure'-related risk factors were identified in the literature. Among 3458 CT colonographies, there were two cases of colonic perforation contributing to an incidence of perforation of 0.06%. There was no statistical correlation between the incidence of perforation and institutional experience (P = 0.66). Risk factors common to both cases and the literatur...
The management of papillary lesions of the breast diagnosed on core needle biopsy is highly conte... more The management of papillary lesions of the breast diagnosed on core needle biopsy is highly contentious. Papillary lesions are epithelial proliferations of breast tissue and are on a continuum of mutations with atypical hyperplastic lesions and in situ carcinoma. With the current literature suggesting that excisional biopsy of papillary lesions might not be required, we discuss a unique case that suggests otherwise. We present a 21-year-old woman with multiple papillary lesions on core biopsy of a breast lesion, and a subsequent excisional biopsy revealing extensive in situ carcinoma of the breast. This finding necessitated total mastectomy. This unique case highlights that core biopsy specimens are unable to effectively exclude adjacent in situ carcinoma and suggests that papillary lesions diagnosed on core needle biopsy require excisional biopsy.
Pediatric low-grade gliomas comprise a diverse range of central nervous system tumors, sharing th... more Pediatric low-grade gliomas comprise a diverse range of central nervous system tumors, sharing the usual course of a slow progression in growth. In individual cases however, the natural history can be variable, and rarely spontaneous regression has been described. This paper describes factors associated with spontaneous regression. A literature review was performed to identify factors associated with spontaneous regression. A unique case is described to contribute to the findings. Low-grade gliomas occurring in association with neurofibromatosis are more likely to spontaneously regress. Only 14 cases of spontaneous regression of low-grade gliomas in patients without neurofibromatosis have been described, and of these, the vast majority regress in association with optic chiasm gliomas. We describe the first documented case of spontaneous regression of a temporal lobe pilocytic astrocytoma in a patient without neurofibromatosis. Spontaneous regression of low-grade gliomas can occur for tumors in a diversity of anatomical locations, at varying ages and in both sexes. This may have implications for management. As such, spontaneous tumor regression is an important outcome to be considered for pediatric low-grade gliomas and pilocytic astrocytomas.
The use of contrast lymphangiography is a relatively new technique in lymphatic anatomical resear... more The use of contrast lymphangiography is a relatively new technique in lymphatic anatomical research, employed as a tool for evaluating lymphatic anatomy in fresh cadaveric specimens. With the use of microsurgical techniques to cannulate lymphatics, contrast media can enable the use of lymphangiography for evaluating lymphatic anatomy. However, the ability to cannulate lymphatics with diameters that are less than the smallest commercially available needles has been a significant limitation, and indeed a challenge. The smallest commercially available hypodermic needles have been 30-gauge needles, with 0.3 mm outer diameters. The lymphatics for cannulation in our studies are of the order of 0.1 mm, and other options have been required. We describe a novel technique for cannulating lymphatic vessels, creating a modified glass hypodermic needle. We have shown that these glass needles can be made with accuracy to diameters as low as 0.01 mm. Although 0.1 mm glass needles are the more commonly utilized in most dissections, we can now accurately create these glass needles to any caliber between 0.01 mm and 0.1 mm, based on the predicted lymphatic anatomy.
Nipple malformations are common congenital or acquired conditions that can have tremendous cosmet... more Nipple malformations are common congenital or acquired conditions that can have tremendous cosmetic, psychological, breast-feeding, sexual, and hygienic ramifications. Ideal reconstruction of the nipple-areola complex (NAC) requires symmetry in position, size, shape, texture, pigmentation, and permanent projection, and although many technical descriptions of NAC reconstruction exist in the medical literature, there are insufficient data presented to accurately compare outcomes. The current article comprises a thorough review of the literature, exploring the techniques described for NAC reconstruction, comparing reported outcomes and complications, and providing an evidence-based approach to NAC reconstruction. The findings of the review suggest that evidence regarding surgical correction of nipple deformity and complete NAC reconstruction is lacking, and loss of nipple projection over time is a pervasive problem common to all flap techniques. A combination of a single pedicle local flap with tattooing for complete NAC reconstruction is currently the most supported method; however, data concerning which type of reconstruction is best suited to immediate versus delayed and type of breast mound remain to be examined.
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Papers by Warren Rozen