Stefan O.P. Hofer's research while affiliated with University of Toronto and other places

Publications (215)

Article
Objective: Rates of bilateral mastectomy are increasing in women with ductal carcinoma in situ (DCIS). We aim to characterize the trajectory of psychosocial outcomes after surgery in women with DCIS. Methods: We have been prospectively collecting psychosocial data on women receiving surgery for stage 0-III breast cancer at University Health Network...
Article
Currently, a large number of skin biopsies are taken for each true skin cancer case detected, creating a need for a rapid, high sensitivity, and specificity skin cancer detection tool to reduce the number of unnecessary biopsies taken from benign tissue. Picosecond infrared laser mass spectrometry (PIRL-MS) using a hand-held sampling probe is repor...
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Concomitant with such a shift toward competency-based curricula, there has been increasing adoption of surgical simulation coupled with virtual, mixed, and augmented reality. These technologies have become more commonplace across multiple surgical disciplines, in domains such as preoperative planning, surgical education, and intraoperative navigati...
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Introduction The deep inferior epigastric perforator (DIEP) flap is regarded as the gold standard for autologous breast reconstruction. However, due to difficulty designing and conducting randomized controlled trials in surgical interventions, the majority of literature on DIEP flap breast reconstructions are observational studies. As such, it is p...
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Human adipose tissue-resident microvascular endothelial cells are not only garnering attention for their emergent role in the pathogenesis of obesity-related metabolic disorders, but are also of considerable interest for vascular tissue engineering due, in part, to the abundant, accessible, and uniquely dispensable nature of the tissue. Here, we de...
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Adipose tissue is an abundant, accessible, and uniquely dispensable source of cells for vascular tissue engineering. Despite its intrinsic endothelial cells, considerable effort is directed at deriving endothelium from its resident stem and progenitor cells. Here, we investigate the composition of human adipose tissue and characterize the phenotype...
Chapter
Abdominal wall reconstruction in a systematic fashion is presented to facilitate decision making and structured management of these defects.
Article
Background:. Breast reconstruction is an important aspect in breast cancer treatment. Methods:. A comprehensive search of MEDLINE, Embase, and the Cochrane Library of Systematic Reviews was performed. Systematic reviews and meta-analyses that focused on breast reconstruction and were published between 2000 and 2020 were included. Quality assessment...
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Endothelial cells are among the fundamental building blocks for vascular tissue engineering. However, a clinically viable source of endothelium has continued to elude the field. Here, we demonstrate the feasibility of sourcing autologous endothelium from human fat – an abundant and uniquely dispensable tissue that can be readily harvested with mini...
Article
568 Background: In breast cancer, clinicians aim to improve survival while patients value quality of life. We aim to delineate the impact of patient, tumour and treatment factors on psychosocial outcomes after treatment. Methods: A prospective cohort of women with unilateral stage I-III breast cancer were recruited at University Health Network in T...
Article
IntroductionRates of bilateral mastectomy are rising in women with unilateral, nonhereditary breast cancer. We aim to characterize how psychosocial outcomes evolve after breast cancer surgery.Patients and Methods We performed a prospective cohort study of women with unilateral, sporadic stage 0–III breast cancer at University Health Network in Toro...
Chapter
Deep sternal wound infection is a rare but serious complication of cardiac operations performed through a median sternotomy. The incidence ranges from 0.75 to 1.44% in large observational studies. Staphylococcus aureus and coagulase negative Staphylococci are the most commonly encountered pathogens. Pedicled bilateral internal mammary artery harves...
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Background: Whether to undergo postmastectomy breast reconstruction (PMBR) is a challenging, preference-sensitive decision. It is therefore paramount to optimize decision quality through ensuring patients' knowledge and aligning treatments with their personal preferences. This study assessed the effects of a preconsultation educational group inter...
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Background: Despite the recent surge in rates of immediate breast reconstruction, there is a paucity of large multicenter studies to compare differences in morbidity after immediate versus delayed breast reconstruction. This study used the National Surgical Quality Improvement Program (NSQIP) to study the association between timing of breast recon...
Article
Background: Flap reconstruction plays an important role in limb preservation after wide resection of extremity soft tissue sarcoma (ESTS), but can be associated with high rates of postoperative wound complications. Currently, no standardized system exists for the classification of these complications. This study aimed to develop a standardized cla...
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Purpose An increasing number of women with unilateral breast cancer are seeking bilateral mastectomies and reconstruction. At our centre, many women who have undergone previous unilateral therapeutic mastectomy request contralateral prophylactic mastectomy (CPM) at the time of delayed reconstruction. These mixed timing reconstructions are particula...
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Background Despite high success rates, flap failure remains an inherent risk in microvascular breast reconstruction. Identifying patients who are at high risk for flap failure would enable us to recommend alternative reconstructive techniques. However, as flap failure is a rare event, identification of risk factors is statistically challenging. Mac...
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Background: Immediate breast reconstruction has many advantages but is associated with higher complication rates than delayed reconstruction. Complications can delay the delivery of adjuvant cancer treatments. This study aimed to develop and validate a risk stratification model for the prediction of perioperative complications in immediate microva...
Article
Background: The rates of contralateral prophylactic mastectomy (CPM) are increasing in women with breast cancer. Previous retrospective research has examined clinical and demographic predictors of the uptake of CPM. However, to the authors' knowledge, there has been very little prospective research to date that has examined psychosocial functionin...
Article
Introduction: Accelerated recovery protocols have proved effective in many surgical procedures but are infrequently applied in breast reconstruction. In this study, we evaluate the impact of a structured pathway for accelerated postoperative recovery in patients undergoing microvascular breast reconstruction at a high-volume center. Methods: We...
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Introduction: Advancements in imaging, surgical, and radiation techniques have made resection of larger and more extensive extremity soft tissue sarcomas (ESTS) possible but with the potential for high complication rates. This study summarizes complication and reoperation rates associated with resection of ESTS and reviews predictors for wound com...
Article
Purpose To compare psychosocial function outcomes in early breast cancer patients treated with breast-conserving surgery (BCS), mastectomy alone (MA), and mastectomy with immediate breast reconstruction (IBR) at 1 year after surgery. Methods Early-stage (stage 0–2) breast cancer patients treated with BCS, MA, and IBR at the University Health Netwo...
Article
Background: Obesity is often considered a relative contra-indication for microvascular autologous breast reconstruction. We hypothesize that although obesity is associated with increased post-operative complications, abdominally based microvascular post mastectomy breast reconstruction can still be achieved with high rates of success. This study a...
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Background: Microvascular breast reconstruction is a complex procedure that can be associated with high complication rates. Although a number of individual predictors of perioperative complications have been identified, few studies have explored interaction between risk factors. Understanding the synergistic effects of multiple risk factors is cen...
Article
Background: The Breast Reconstruction Assessment (BRA)-score is a disease-specific risk calculator that estimates the likelihood of postoperative complications in an individual patient. The tool has not been previously externally validated in microvascular breast reconstruction. The purpose of this study was to evaluate the efficacy of the calcula...
Article
Background and Objectives The deep inferior epigastric perforator (DIEP) flap may be associated with less long‐term donor‐site morbidity compared with free muscle‐sparing transverse rectus abdominis myocutaneous flap (MS‐TRAM) flap. However, DIEP flaps may have longer operative time and higher rates of acute postoperative complications. We performe...
Data
Figure S1. Immunophenotype of adipose‐derived mesenchymal stem cells (ASCs). ASCs isolated from the stromal vascular fraction of enzymatically digested human subcutaneous abdominal white adipose tissue were cultured, stained with combinations of fluorophore‐conjugated monoclonal antibodies, and evaluated by flow cytometry. Representative dot plots...
Data
Figure S2. Uptake of acetylated low density lipoprotein (AcLDL) by adipose‐derived mesenchymal stem cells (ASCs). Unconditioned ASC controls (N = 3), ASCs conditioned in endothelial cell (EC) growth medium‐2 (EGM2) for 14 days (N = 3), and the three distinct EC controls (N = 3) were incubated with Alexa Fluor 488 ‐conjugated AcLDL for 4 hrs, after...
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Considerable effort has been directed toward deriving endothelial cells (ECs) from adipose-derived mesenchymal stem cells (ASCs) since 2004, when it was first suggested that ECs and adipocytes share a common progenitor. While the capacity of ASCs to express endothelial markers has been repeatedly demonstrated, none constitute conclusive evidence of...
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This qualitative inquiry reports on the embodied experience of women with breast cancer considering post-mastectomy delayed breast reconstruction (DBR). In a pilot randomized controlled trial evaluating an educational workshop on decision-making about DBR, a purposeful sample of eight women participated in telephone semi-structured interviews. The...
Article
Background: Flap reconstruction plays an essential role in facilitating limb preservation in patients with extremity soft tissue sarcoma (ESTS). However, the effect of flap choice on the rates of postoperative complications and functional outcomes has not been clearly established. This study directly compares the outcomes of free and pedicled flap...
Article
Background: Lentigo maligna is an in situ form of cutaneous melanoma that commonly arises on the head and neck. Various surgical and nonsurgical treatment options are available but no randomized trials exist to guide practice. Objective: To determine the current treatment practices for lentigo maligna of the head and neck in Ontario, Canada. Ma...
Article
Background: Flap reconstruction plays an essential role in the surgical management of extremity soft tissue sarcoma (ESTS) for many patients. But flaps increase the duration and complexity of the surgery and their contribution to overall morbidity is unclear. This study directly compares the complication rates in patients with ESTS undergoing eith...
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Objective Soft-tissue sarcomas are most frequently located deep within myofascial compartments. Superficial soft-tissue sarcomas (S-STS) are relatively less common and may be managed differently than deep sarcomas because generous resection margins are often possible without sacrificing critical structures. We sought to investigate the frequency an...
Article
Background: The decision to have post-mastectomy breast reconstruction (PMBR) is highly complex and many women feel ill equipped to make this decision. Decision aids have been advocated to promote patient involvement in decision-making by streamlining and standardizing communication between the patient and the health care professional. In this stu...
Article
This article reviews the indications and controversies in abdominally based autologous breast reconstruction. The evidence regarding these indications and controversies will be appraised and summarized. Finally, we will provide a summary of our approach and technique for the patient undergoing autologous breast reconstruction using abdominally base...
Article
Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a rare disease that has been diagnosed in an extremely small proportion of women with breast implants. The pathogenesis of this disease is currently poorly understood, but it appears to be related to textured implants. Recent high-profile media coverage of this rare clinical ent...
Article
Background: Complications following immediate breast reconstruction can have significant consequences for the delivery of postoperative chemotherapy and radiation therapy. Identifying patients at higher risk of complications would ensure that immediate breast reconstruction does not compromise oncologic treatment. The American College of Surgeons...
Article
Background: Chronic postsurgical pain (CPSP) is a debilitating and costly condition. Risk factors for CPSP after autologous breast reconstruction have not been clearly established. Previously, we demonstrated that transversus abdominis plane (TAP) catheters delivering intermittent local anesthetic reduced postoperative morphine consumption. This p...
Article
The publisher regrets that the name of the author Stefan Hofer was not represented in its full form in the original version of this article. This author should be referred to as Stefan O.P. Hofer. The publisher would like to apologise for any inconvenience caused. © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons
Article
Background: This is the first study to use generic distress, cancer-specific, and procedure-specific measures to prospectively evaluate psychological responses, body image, sexuality, and health-related quality of life in immediate compared with delayed breast reconstruction. Methods: Consecutive patients undergoing autologous immediate and dela...
Article
Introduction: The ACS-NSQIP surgical risk calculator is an open-access on-line tool that estimates the risk of adverse post-operative outcomes for a wide range of surgical procedures. Wide surgical resection of soft tissue sarcoma (STS) often requires complex reconstructive procedures that can be associated with relatively high rates of complicati...
Article
Introduction: Microvascular complications can have devastating consequences in breast reconstruction. Because of the relatively low rate of complications, it can be difficult to identify significant predictors of failure. This study explores the importance of intraoperative microvascular problems in the development of postoperative complications a...
Article
Aim: To examine trends of contralateral prophylactic mastectomy (CPM) rates at a Canadian academic breast cancer center. Methods: A single-institution retrospective cohort study was completed. Women of any age who underwent at least a unilateral mastectomy (UM) for primary unilateral breast carcinoma between January 1, 2004 and December 31, 2010...
Article
Introduction: The American College of Surgeons National Surgery Quality Improvement Program (ACS NSQIP) Surgical Risk Calculator is an open access online tool that estimates the risk of adverse post-operative events for a wide range of surgical procedures. This study evaluates the predictive value of the ACS NSQIP calculator in patients undergoing...
Article
Introduction: With increasing appreciation of the possible adverse effects of peri-operative blood transfusion, restrictive policies regarding use of blood products have been adopted in many surgical specialties. Although microvascular breast reconstruction has become a routine procedure, high peri-operative transfusion rates continue to be report...
Article
Background and aim: Although the internal mammary vessels are, for many surgeons, the recipient vessels of choice in microvascular breast reconstruction, there continues to be some debate regarding their use. The reliability of these vessels, particularly the vein, has been called into question, with high rates of conversion to alternative vessels...
Article
More CTAs are routinely ordered prior to breast reconstruction using deep inferior epigastric perforator (DIEP) flaps to provide better surgical planning and improve preoperative decision-making. These investigations occasionally result in unexpected findings in otherwise asymptomatic women. Unexpected findings on imaging in a population of women w...
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Plastic surgery as a specialty has embraced evidence-based medicine.1,2 With innovation at their core, plastic surgeons are striving to increase the levels of evidence in their specialty. This paradigm shift to evidence-based medicine has the potential to improve quality of care and patient safety in areas traditionally lacking evidence such as aes...
Chapter
The abdominal wall is a complex myofascial structure that prevents exenteration of the abdominal viscerae and supports numerous essential physiological processes. Defects of the abdominal wall therefore result in both localized and systemic dysfunction. The goals of abdominal wall reconstruction are to restore dynamic function and structure includi...
Article
Background The importance of facial contouring with facial nerve reconstruction following total and radical parotidectomy is often overlooked. The goal of this study was to quantify the level of facial disfigurement and nerve dysfunction following reconstruction of the facial nerve, with or without reconstruction of the contours, using free tissue...
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Full-text available
Achieving an aesthetic outcome following postmastectomy breast reconstruction is both an important goal for the patient and plastic surgeon. However, there is currently an absence of a widely accepted, standardized, and validated professional aesthetic assessment scale following postmastectomy breast reconstruction. A systematic review was performe...
Article
Background: The analgesic efficacy of the transversus abdominis plane peripheral nerve block following abdominal tissue breast reconstruction has not been studied in a randomized controlled trial. Methods: The authors conducted a double-blind, placebo-controlled, 1:1 allocation, two-arm parallel group, superiority design, randomized controlled t...
Article
Full-text available
Purpose Breast cancer survivors who make preference-sensitive decisions about postmastectomy breast reconstruction often have large gaps in knowledge and undergo procedures that are misaligned with their treatment goals. We evaluated the feasibility and effect of a pre-consultation educational group intervention on the decision-making process for b...
Article
Full-text available
A recent revival of global interest for reconstruction of long-segment tracheal defects, which represents one of the most interesting and complex problems in head and neck and thoracic reconstructive surgery, has been witnessed. The trachea functions as a conduit for air, and its subunits including the epithelial layer, hyaline cartilage, and segme...
Article
Purpose: To describe the population-based rates of immediate breast reconstruction (IBR) for all women undergoing mastectomy for treatment or prophylaxis of breast cancer in the past decade, and to evaluate geographic, institutional, and patient factors that influence use in the publically funded Canadian health care system. Methods: This popula...
Article
The bipedicle deep inferior epigastric artery perforator (DIEP) flap allows reliable transfer of the entire lower abdominal flap in patients who have a small pannus or require a large volume breast reconstruction. Selection of recipient vessels for the second pedicle can however, be challenging. We describe our experience with a consecutive series...
Article
Infections following implant-based breast reconstruction can lead to devastating consequences. There is currently no consensus on the need for post-operative antibiotics in preventing immediate infection. This study compared two different methods of infection prevention in this group of patients. A retrospective matched cohort study was performed o...
Article
Previous studies comparing muscle-sparing transverse rectus abdominis myocutaneous (TRAM) versus deep inferior epigastric artery perforator (DIEP) free flaps have not considered procedure selection bias. Propensity score analysis provides a statistical approach to consider preoperative factors in flap selection, and was used to compare major compli...
Article
To determine the effect of flap reconstruction on perineal complications in locally advanced rectal cancers (LARC) and locally recurrent rectal cancers (LRRC). Prior studies have suggested that flap reconstruction may decrease wound complications after ablative surgery for rectal cancer but are limited by small sample sizes, heterogeneity of pathol...
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Tracheal transplantation with a long-segment recellularized tracheal allograft has previously been performed without the need for immunosuppressive therapy. Recipients' mesenchymal stromal cells (MSC) and tracheal epithelial cells (TEC) were harvested, cultured, expanded and seeded on a donor trachea within a bioreactor. Prior techniques used for c...
Article
It is not known if optimism influences regret following major reconstructive breast surgery. We examined the relationship between dispositional optimism, major complications and decision regret in patients undergoing microsurgical breast reconstruction. A consecutive series of 290 patients were surveyed. Independent variables were: (1) dispositiona...
Article
The relationship between satisfaction with information and decision regret has not been previously studied in breast reconstruction patients. The objective of this study, therefore, was to assess this relationship and the factors that may influence satisfaction with preoperative information, including self-efficacy (confidence with seeking medical...
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Full-text available
Background: The two-stage tissue expander/implant (TE/I) reconstruction is currently the gold standard method of implant-based immediate breast reconstruction in North America. Recently, however, there have been numerous case series describing the use of one-stage direct to implant reconstruction with the aid of acellular dermal matrix (ADM). In o...
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Full-text available
Purpose: Breast cancer survivors who make preference-sensitive decisions about postmastectomy breast reconstruction often have large gaps in knowledge and undergo procedures that are misaligned with their treatment goals. We evaluated the feasibility and effect of a pre-consultation educational group intervention on the decision-making process for...
Article
Neoadjuvant radiotherapy followed by surgical resection and soft tissue reconstruction provides the best possibility of achieving superior limb function in soft tissue sarcomas. The aim of this study was to report our experience of free flap microsurgical reconstruction of recently irradiated soft tissue sarcoma defects. A retrospective study of mi...
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Background: Multiple preoperative, intraoperative and postoperative decisions can influence the outcome of microsurgical breast reconstruction. We have simplified the decision-making process by incorporating a number of algorithms into our microsurgical breast reconstruction practice and critically review our results in this study. Methods: Pros...
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Background: The purpose of this study was to evaluate bony union and resorption after free fibular flap reconstruction for mandibular reconstruction. Methods: A total of 112 patients with composite resection and reconstruction with a fibular free flap were included. Computed tomography scan images taken after the reconstruction and approximately...
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: In autogenous muscle transplantation, unpredictable complications can cause prolonged ischemia, resulting in ischemia-reperfusion injury. The authors investigated the efficacy and mechanism of nicorandil, a nitrovasodilator and adenosine triphosphate-sensitive potassium channel opener, in inducing perioperative protection of muscle flaps from isc...
Article
Background: Upper limb preservation after soft tissue sarcoma resection often requires flap reconstruction. The aim of this study was to compare pre- and post-operative upper limb function following shoulder, elbow or wrist/hand sarcoma resection and soft tissue reconstruction with a pedicled or free flap. Patients: Between 1989 and 2008, 113 pa...