The utility of three-dimensional models in complex microsurgical reconstruction

HoloDIEP-Faster and More Accurate Intraoperative DIEA Perforator Mapping Using a Novel Mixed Reality Tool

BACKGROUND

 Microsurgical breast reconstruction using abdominal tissue is a complex procedure, in part, due to variable vascular/perforator anatomy. Preoperative computed tomography angiography (CTA) has mitigated this challenge to some degree; yet it continues to pose certain challenges. The ability to map perforators with Mixed Reality has been demonstrated in case studies, but its accuracy has not been studied intraoperatively. Here, we compare the accuracy of "HoloDIEP" in identifying perforator location (vs. Doppler ultrasound) by using holographic 3D models derived from preoperative CTA.

METHODS

 Using a custom application on HoloLens, the deep inferior epigastric artery vascular tree was traced in 15 patients who underwent microsurgical breast reconstruction. Perforator markings were compared against the 3D model in a coordinate system centered on the umbilicus. Holographic- and Doppler-identified markings were compared using a perspective-corrected photo technique against the 3D model along with measurement of duration of perforator mapping for each technique.

RESULTS

 Vascular points in HoloDIEP skin markings were -0.97 ± 6.2 mm (perforators: -0.62 ± 6.13 mm) away from 3D-model ground-truth in radial length from the umbilicus at a true distance of 10.81 ± 6.14 mm (perforators: 11.40 ± 6.15 mm). Absolute difference in radial distance was twice as high for Doppler markings compared with Holo-markings (9.71 ± 6.16 and 4.02 ± 3.20 mm, respectively). Only in half of all cases (7/14), more than 50% of the Doppler-identified points were reasonably close (<30 mm) to 3D-model ground-truth. HoloDIEP was twice as fast as Doppler ultrasound (76.9s vs. 150.4 s per abdomen).

CONCLUSION

 HoloDIEP allows for faster and more accurate intraoperative perforator mapping than Doppler ultrasound.

Comparison of Iomeprol-400, Ultravist-370, and Omnipaque-350 in Preoperative Computed Tomography for Visualizing the Deep Inferior Epigastric Perforators

Background

Breast reconstruction using the deep inferior epigastric perforator (DIEP) flap is considered the gold standard, due to its natural results and minimal damage to the donor site. Precise preoperative imaging to identify optimal perforators is essential for successful DIEP flap surgery, improving surgical outcomes and patient satisfaction. This study evaluates the efficacy of Iomeprol-400, a high iodine concentration contrast agent, against Ultravist-370 and Omnipaque-350 in enhancing visualization of DIEPs on preoperative computed tomography angiography (CTA).

Methods

We performed a retrospective comparative study of 40 female patients who underwent preoperative CTA with contrast injection of Iomeprol-400 and 40 matched controls following the injection of either Ultravist-370 or Omnipaque-350. Arterial phase enhancement in Hounsfield units was measured at the abdominal aorta, proximal and distal deep inferior epigastric arteries (DIEAs), and DIEP. Although measurements were collected at the aorta, these were excluded from statistical analysis due to nonnormal distribution.

Results

Significant differences in arterial enhancement were found between the groups. The Iomeprol-400 group showed higher enhancement at the proximal DIEA (P < 0.001), distal DIEA (P = 0.004), and at the DIEP (P < 0.001).

Conclusions

Iomeprol-400 significantly improves visualization of critical small-diameter vessels in preoperative CTA for DIEP flap surgery compared with Ultravist-370 and Omnipaque-350. These findings support incorporating higher iodine concentration agents such as Iomeprol-400 into preoperative imaging protocols for DIEP flap surgery.

From printer to patient: A scoping review and new classification of ready-to-use three-dimensional printed constructs in autologous breast reconstruction

BACKGROUND

Three-dimensional (3D) printing has been successfully used in several plastic and reconstructive surgery subspecialties; however, it is still a relatively new concept in the field of autologous breast reconstruction. There is no study describing these 3D-printed constructions and their clinical impact in autologous breast reconstruction.

METHODS

We conducted a scoping review and searched PubMed, Embase, Web of Science, Cochrane, and Scopus. From these articles, we extracted data regarding the 3D-printed construct, the timepoint at which the construct was used, the types of surgeries the construct was used in, the method, material, and cost to 3D print the construct, intraoperative time, length of hospitalization, postoperative complications, and various outcomes.

RESULTS

We retrieved 329 articles, 11 of which met our inclusion criteria. There was a total of 137 3D-printed constructs described in the literature. We classified the three types of constructs as such: Type IA are breast bio-models (2.9%, n = 4), Type IB are breast molds (32.8%, n = 45), and Type II are perforator templates (64.2%, n = 88). Three studies reported significant reductions in intraoperative time when using 3D-printed constructs, but no significant reductions in postoperative complications, reoperations, or flap failures. These three constructs serve both preoperative and intraoperative functions for a wide range of autologous reconstructions.

CONCLUSIONS

Three-dimensional printing represents a promising new technology in autologous breast reconstruction. We developed a new classification system for ready-to-use 3D-printed constructs that can be used as a guide for future applications in autologous breast reconstruction.

Utility of 3D-printed vascular modeling in microsurgical breast reconstruction: a systematic review

BACKGROUND

Microsurgical breast reconstruction presents a technical challenge in preoperative planning and flap harvest. Given the limitations of computed tomographic angiography as a preoperative aid, 3D printing has emerged as an avenue for creating patient-specific anatomical models for pre- and intraoperative use. This systematic review assesses the current use and utility of 3D-printed vascular models (3DVMs) in microsurgical breast reconstruction.

METHODS

MEDLINE, Embase, and CENTRAL were searched for English articles published from 1946 to 2024. Studies utilizing 3D-printed vascular modeling in the context of microsurgical breast reconstruction were included if they reported surgical, model-, or user-related outcomes. The Newcastle-Ottawa Scale and Joanna Briggs Institute checklists were used for quality assessment. Results were reported according to PRISMA guidelines.

RESULTS

Six hundred and nineteen records were retrieved. Following specific inclusion and exclusion criteria, 29 studies underwent full-text review. Eight studies totaling 181 patients and 261 flaps were included in the final analysis. 3DVMs were used to model deep inferior epigastric perforator (DIEP) and muscle-sparing transverse rectus abdominis myocutaneous (MS-TRAM) flap perforator origin, course, distribution, and surrounding anatomy. They were used for perforator selection, flap harvest, and training. Use of 3DVMs reduced harvest time by up to 23 min per case. No complications or preoperative plan deviations were reported in 3DVM-guided cases. Surgeons endorsed significant model utility in anatomical visualization, preoperative planning, and flap harvest. Model cost, production time, and adoption were identified as barriers to use.

CONCLUSIONS

3DVMs can enhance preoperative planning, intraoperative decision-making, and operative efficiency in unilateral DIEP and bilateral MS-TRAM flap breast reconstructions.

Three-Dimensional Printing in Breast Reconstruction: Current and Promising Applications

Three-dimensional (3D) printing is dramatically improving breast reconstruction by offering customized and precise interventions at various stages of the surgical process. In preoperative planning, 3D imaging techniques, such as computer-aided design, allow the creation of detailed breast models for surgical simulation, optimizing surgical outcomes and reducing complications. During surgery, 3D printing makes it possible to customize implants and precisely shape autologous tissue flaps with customized molds and scaffolds. This not only improves the aesthetic appearance, but also conforms to the patient's natural anatomy. In addition, 3D printed scaffolds facilitate tissue engineering, potentially favoring the development and integration of autologous adipose tissue, thus avoiding implant-related complications. Postoperatively, 3D imaging allows an accurate assessment of breast volume and symmetry, which is crucial in assessing the success of reconstruction. The technology is also a key educational tool, enhancing surgeon training through realistic anatomical models and surgical simulations. As the field evolves, the integration of 3D printing with emerging technologies such as biodegradable materials and advanced imaging promises to further refine breast reconstruction techniques and outcomes. This study aims to explore the various applications of 3D printing in breast reconstruction, addressing current challenges and future opportunities.

Precision Surgery for Orbital Cavernous Hemangiomas: The Role of Three-Dimensional Printing in Individualized Resection-An Educational Experience

Orbital cavernous hemangiomas are the most common primary orbital tumors in adults, providing challenges for optimal surgical approach planning within an anatomically complex area with close proximity to vital neurovascular structures. The authors present an individualized lateral mini-orbitozygomatic approach for the resection of an orbital cavernous haemangioma based on a preoperative 3-dimensional-printed model. This individualized approach enabled the surgeons to achieve optimal exposure while maintaining safety during the resection of the lesion, but also to respect the patient's physiognomy and hairline. In addition, the model was used for patient informed consent, helping the patient understand the procedure. Although adding additional effort to preoperative planning, 3-dimensional model-based approaches can offer great benefits when it comes to customizing surgical approaches, especially for anatomically challenging resections.

3D printing for an anterolateral thigh phalloplasty

BACKGROUND

Phalloplasty procedures are performed to create a phallus, typically as a gender-affirming surgery for treating gender dysphoria. Due to the controversial nature of this specific procedure, more innovation is needed to directly assist surgical teams in this field. As a result, surgeons are left to improvise and adapt tools created for other procedures to improve surgical outcomes. This study developed a patient-specific 3D printed model from segmented computed tomography (CT) scans to accurately represent the relevant vasculature necessary for anterolateral thigh (ALT) flap phalloplasty. The surgical procedure seeks to maintain intact vessels that derive from the descending branch of the lateral circumflex femoral artery, typically found traveling within the intermuscular septum between the rectus femoris and vastus lateralis.

METHODS

In this study, we created and printed 3D models of the leg and vasculature using two techniques: (1) a standard segmentation technique with the addition of a reference grid and (2) a bitmap method in which the total CT volume is colorized and printed.

RESULTS

The results gathered included the physician's view on the model's accuracy and visualization of relevant anatomy. Bitmap-printed models resulted in a high amount of detail, eliciting surgeons' undesirable reactions due to the excess of information. The hybrid method produced favorable results, indicating positive feasibility.

CONCLUSIONS

This study tested the ability to accurately print a patient-specific 3D model that could represent the vasculature necessary for ALT flap procedures and potentially be used in surgical reference and planning in the future. A surgeon performing phalloplasty procedures discussed their approval of both models and their preference for grid creation and application.

Hybrid modeling techniques for 3D printed deep inferior epigastric perforator flap models

BACKGROUND

Deep Inferior Epigastric Perforator Flap (DIEP) surgical procedures have benefited in recent years from the introduction of 3D printed models, yet new technologies are expanding design opportunities which promise to improve patient specific care. Numerous studies, utilizing 3D printed models for DIEP, have shown a reduction of surgical time and complications when used in addition to the review of standard CT imaging. A DIEP free flap procedure requires locating the inferior epigastric perforator vessels traversing and perforating the rectus abdominis muscle, perfusing the abdominal skin and fatty tissue. The goal of dissecting the inferior epigastric perforator vessels is complicated by the opacity of the fatty tissue and muscle. Previous attempts to 3D print patient specific models for DIEP free flap cases from CT imaging has shown a wide range of designs which only show variations of perforator arteries, fatty tissue, and the abdominis rectus muscle.

METHODS

To remedy this limitation, we have leveraged a voxel-based modeling environment to composite complex modeling elements and incorporate a ruled grid upon the muscle providing effortless 'booleaning' and measured guidance.

RESULTS

A limitation of digital surface-based modeling tools has led to existing models lacking the ability to composite critical anatomical features, such as differentiation of vessels through different tissues, coherently into one model, providing information more akin to the surgical challenge.

CONCLUSION

With new technology, highly detailed multi-material 3D printed models are allowing more of the information from medical imaging to be expressed in 3D printed models. This additional data, coupled with advanced digital modeling tools harnessing both voxel- and mesh-based modeling environments, is allowing for an expanded library of modeling techniques which create a wealth of concepts surgeons can use to assemble a presurgical planning model tailored to their setting, equipment, and needs.

TRIAL REGISTRATION

COMIRB 21-3135, ClinicalTrials.gov ID: NCT05144620.

The Innovation Press: A Primer on the Anatomy of Digital Design in Plastic Surgery

ABSTRACT

Three-dimensional (3D) printing continues to revolutionize the field of plastic surgery, allowing surgeons to adapt to the needs of individual patients and innovate, plan, or refine operative techniques. The utility of this manufacturing modality spans from surgical planning, medical education, and effective patient communication to tissue engineering and device prototyping and has valuable implications in every facet of plastic surgery. Three-dimensional printing is more accessible than ever to the surgical community, regardless of previous background in engineering or biotechnology. As such, the onus falls on the surgeon-innovator to have a functional understanding of the fundamental pipeline and processes in actualizing such innovation. We review the broad range of reported uses for 3D printing in plastic surgery, the process from conceptualization to production, and the considerations a physician must make when using 3D printing for clinical applications. We additionally discuss the role of computer-assisted design and manufacturing and virtual and augmented reality, as well as the ability to digitally modify devices using this software. Finally, a discussion of 3D printing logistics, printer types, and materials is included. With innovation and problem solving comprising key tenets of plastic surgery, 3D printing can be a vital tool in the surgeon's intellectual and digital arsenal to span the gap between concept and reality.

Three-Dimensional Photography and Computer Modeling as a Reconstructive Surgical Training Tool

Background

Reconstructive surgery operations are often complex, staged, and have a steep learning curve. As a vocational training requiring thorough three-dimensional (3D) understanding of reconstructive techniques, the use of 3D photography and computer modeling can accelerate this learning for surgical trainees.

Objectives

The authors illustrate the benefits of introducing a streamlined reconstructive pathway that integrates 3D photography and computer modeling, to create a learning database for use by trainees and patients alike, to improve learning and comprehension.

Methods

A computer database of 3D photographs and associated computer models was developed for 35 patients undergoing reconstructive facial surgery at the Royal Free Hospital, London, UK. This was used as a training and teaching tool for 20 surgical trainees, with an MCQ questionnaire assessing knowledge and a Likert scale questionnaire assessing satisfaction with the understanding of core reconstructive techniques, given before and after teaching sessions. Data were analyzed using the Mann-Whitney U test for trainee knowledge and Wilcoxon rank sum test for trainee satisfaction.

Results

Trainee (n = 20) knowledge showed a statistically significant improvement, P < .01, as did trainee satisfaction, P < .05, after a teaching session using 3D photography and computer models for facial reconstruction.

Conclusions

Three-dimensional photography and computer modeling are useful teaching and training tools for reconstructive facial surgery. The authors advocate the implementation of an integrated pathway for patients with facial defects to include 3D photography and computer modeling wherever possible, to develop internal databases for training trainees as well as patients. This algorithm can be extrapolated to other aspects of reconstructive surgery.

Level of Evidence 5

Nanomedicine and nanoparticle-based delivery systems in plastic and reconstructive surgery

BACKGROUND

Nanotechnology and nanomedicine are rising novel fields in plastic and reconstructive surgery (PRS). The use of nanomaterials often goes with regenerative medicine. Due to their nanoscale, these materials stimulate repair at the cellular and molecular levels. Nanomaterials may be placed as components of nanocomposite polymers allowing enhancement of overall biochemical and biomechanical properties with improved scaffold properties, cellular attachment, and tissue regeneration. They may also be formulated as nanoparticle-based delivery systems for controlled release of signal factors or antimicrobials, for example. However, more studies on nanoparticle-based delivery systems still need to be done in this field. Nanomaterials are also used as frameworks for nerves, tendons, and other soft tissues.

MAIN BODY

In this mini-review, we focus on nanoparticle-based delivery systems and nanoparticles targeting cells for response and regeneration in PRS. Specifically, we investigate their roles in various tissue regeneration, skin and wound healing, and infection control. Cell surface-targeted, controlled-release, and inorganic nanoparticle formulations with inherent biological properties have enabled enhanced wound healing, tumor visualization/imaging, tissue viability, and decreased infection, and graft/transplantation rejection through immunosuppression.

CONCLUSIONS

Nanomedicine is also now being applied with electronics, theranostics, and advanced bioengineering technologies. Overall, it is a promising field that can improve patient clinical outcomes in PRS.

Radiological Society of North America (RSNA) 3D Printing Special Interest Group (SIG) clinical situations for which 3D printing is considered an appropriate representation or extension of data contained in a medical imaging examination: breast conditions

The use of medical 3D printing has expanded dramatically for breast diseases. A writing group composed of the Radiological Society of North America (RSNA) Special Interest Group on 3D Printing (SIG) provides updated appropriateness criteria for breast 3D printing in various clinical scenarios. Evidence-based appropriateness criteria are provided for the following clinical scenarios: benign breast lesions and high-risk breast lesions, breast cancer, breast reconstruction, and breast radiation (treatment planning and radiation delivery).

A novel computed tomography angiography technique: guided preoperative localization and design of anterolateral thigh perforator flap

BACKGROUND

Anterolateral thigh perforator (ALTP) flap is considered a versatile flap for soft tissue reconstruction. Computed tomography angiography (CTA) is used for mapping perforator in abdominal-based reconstruction; however, it is less commonly used in ALTP due to its poor imaging efficacy. In this study, we introduced a novel CTA technique for preoperative localization and design of ALTP flap and evaluated its value in directing surgical reconstruction.

RESULTS

Thirty-five patients with soft tissue defects were consecutively enrolled. Modified CTA procedures, such as sharp convolution kernel, ADMIRE iterative reconstruction, 80 kV tube voltage, high flow contrast agent and cinematic rendering image reconstruction, were used to map ALTPs. A total of 287 perforators (including 884 sub-branches) were determined, with a mean of 5 perforators per thigh (range 2-11). The ALTPs were mainly concentrated in the "hot zone" (42%, 121/287) or the distal zone (41%, 118/287). Most perforators originated from the descending branch of the lateral circumflex femoral artery (76%, 219/287). Three perforator types, namely musculocutaneous (62%, 177/287), septocutaneous (33%, 96/287), and mixed pattern (5%, 14/287), were identified. The median pedicle length measured by two methods was 4.1 cm (range 0.7-20.3 cm) and 17.0 cm (range 4.7-33.9 cm), respectively, and the median diameter of the skin flap nourished by one perforator was 3.4 cm (IQR 2.1-5.7 cm). Twenty-eight ALTP flaps were obtained with the guidance of CTA, and 26 flaps survived after follow-up.

CONCLUSIONS

The proposed CTA mapping technique is a useful tool for preoperative localization and design of ALTP flap.

Imaging diagnosis and research progress of carotid plaque vulnerability

Ischemic stroke (IS) exhibits a high disability rate, mortality, and recurrence rate, imposing a serious threat to human survival and health. Its occurrence is affected by various factors. Although the previous research has demonstrated that the occurrence of IS is mainly associated with lumen stenosis caused by carotid atherosclerotic plaque (AP), recent studies have revealed that many patients will still suffer from IS even with mild carotid artery lumen stenosis. Blood supply disturbance causes 10% of IS to the corresponding cerebral blood supply area caused by carotid vulnerable plaque. Thrombus blockage of distal branch vessels caused by rupture of vulnerable carotid plaque is the main cause of ischemic stroke. Therefore, how to accurately evaluate vulnerable plaque and intervene as soon as possible is a problem that needs to be solved in clinic. The vulnerability of plaque is determined by its internal components, including thin and incomplete fibrous cap, necrotic lipid core, intra-plaque hemorrhage, intra-plaque neovascularization, and ulcerative plaque formation. The development of imaging technology enables the routine detection of AP vulnerability. By analyzing the pathological changes, characteristics, and formation mechanism of carotid plaque vulnerability, this article aims to explore the modern imaging methods which can be used to identify plaque composition and plaque vulnerability to provide a reference basis for disease diagnosis and differential diagnosis.

3D and 4D Printing in the Fight against Breast Cancer

Breast cancer is the second most common cancer worldwide, characterized by a high incidence and mortality rate. Despite the advances achieved in cancer management, improvements in the quality of life of breast cancer survivors are urgent. Moreover, considering the heterogeneity that characterizes tumors and patients, focusing on individuality is fundamental. In this context, 3D printing (3DP) and 4D printing (4DP) techniques allow for a patient-centered approach. At present, 3DP applications against breast cancer are focused on three main aspects: treatment, tissue regeneration, and recovery of the physical appearance. Scaffolds, drug-loaded implants, and prosthetics have been successfully manufactured; however, some challenges must be overcome to shift to clinical practice. The introduction of the fourth dimension has led to an increase in the degree of complexity and customization possibilities. However, 4DP is still in the early stages; thus, research is needed to prove its feasibility in healthcare applications. This review article provides an overview of current approaches for breast cancer management, including standard treatments and breast reconstruction strategies. The benefits and limitations of 3DP and 4DP technologies are discussed, as well as their application in the fight against breast cancer. Future perspectives and challenges are outlined to encourage and promote AM technologies in real-world practice.

Retrospective review of 108 breast reconstructions using the round block technique after breast-conserving surgery: Indications, complications, and outcomes

Background

Several oncoplastic approaches have been implemented in recent years to enhance cosmetic results and to reduce complications. The round block technique is a volume displacement technique for breast reconstruction after breast-conserving surgery (BCS). However, its indications are currently limited according to tumor location, and its cosmetic results and complications have not been clearly established. We hypothesized that the round block technique could produce favorable cosmetic results without major complications regardless of tumor location or nipple-tumor distance, below a certain resected tumor volume and tumor-breast volume ratio.

Methods

All breast reconstructions using the round block technique after BCS were included in this analysis. Patients’ data were reviewed retrospectively to investigate complications during follow-up, and clinical photos were used to evaluate cosmetic results. The relationships of tumor location, nipple-tumor distance, tumor volume, and the tumor-breast volume ratio with cosmetic results were investigated.

Results

In total, 108 breasts were reconstructed. The mean resected tumor volume was 30.2±15.0 mL. The cosmetic score was 4.5±0.6 out of 5. Tumor location, nipple-tumor distance, tumor volume, tumor-breast volume ratio, radiotherapy, and chemotherapy had no significant effects on cosmetic results or complications. There were no major complications requiring reoperation.

Conclusions

Breast reconstruction using the round block technique after BCS can lead to good cosmetic results without major complications regardless of the tumor location, nipple-tumor distance, radiotherapy, or chemotherapy. Below the maximum tumor volume (79.2 mL) and the maximum tumor-breast volume ratio (14%), favorable results were consistently obtained.