Keywords flap design - reconstruction assessment - tissue defect - flap surgery - sterile tissue
paper
Flap design is a cornerstone of modern reconstructive surgery, with its origins tracing
back to around 1000 to 800 BC when Sushruta, a pioneer in surgical techniques in Samahita,
India, first described the use of a regional pedicle flap for nasal reconstruction.
This marked the beginning of flap surgery as a key method for tissue restoration.[1 ] Over time, surgical advancements and a deeper understanding of human anatomy and
physiology have led to significant improvements in flap application. Currently, flaps
are widely used to reconstruct tissue defects resulting from trauma, oncologic resection,
congenital anomalies, and chronic wounds.
A deep understanding of the anatomy and physiology of both the defect and potential
donor sites is essential for the success of flap transfer, along with mastery of atraumatic
soft tissue surgical techniques.[2 ] The key principle of this procedure is the precise “replacement of like with like,”
which involves the strategic creation and transfer of tissue flaps to restore both
form and function in areas affected by tissue loss.[3 ] The practice of flap design and transfer combines medical science with surgical
artistry, often determining whether the procedure yields highly successful results.
The choice of flap type depends on factors such as the defect's location and size,
availability of adjacent tissue, and required vascularization.[4 ] Flaps offer a significant advantage in addressing complex defects owing to their
versatility in design and ability to incorporate different tissue types. This approach
allows personalized reconstruction based on patient needs. The selection of the appropriate
flap requires thorough patient evaluation and careful planning. An incorrect choice
can lead to complications, such as tissue necrosis, due to inadequate blood supply
to the recipient site.[5 ]
Furthermore, flap procedures require specialized skills, particularly in microsurgery,
when dealing with free flaps. Continuous research and technical advancements are critical
for reconstructive surgery. Three-dimensional (3D) visualization of tissue defects
is crucial for surgical planning and medical education. Although advanced techniques,
such as imaging and digital modeling, have improved the precision of tissue assessment
and preoperative planning, they are expensive and may lack the tactile feedback essential
for some applications.[6 ]
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This technical note introduces an innovative approach that uses sterile tissue paper
to construct 3D models of tissue defects. This method offers an accessible, cost-effective,
and efficient solution for enhancing the understanding of anatomical structures and
the extent of tissue damage, providing valuable support in both clinical and educational
settings.
Methods
The materials used were carefully selected to ensure precision and sterility during
the flap design process. Sterile tissue paper was chosen for its flexibility and ease
of manipulation, making it ideal for creating accurate 3D models of the flap. A total
of nine steps explaining three main processes, involving designing the flap and its
pedicle, trimming the model, and placing it on the defect, were carried out ([Fig. 1 ]).
Fig. 1 Step-by-step creation of a 3D tissue paper model for defect measurement in flap surgery
visualization. ALT, anterolateral thigh; 3D, three-dimensional.
A sterile surgical marker was used to trace and mark the tissue paper, allowing precise
delineation of the defect and flap design. Surgical scissors provided the necessary
precision to cut the tissue paper according to the marked outlines, thereby ensuring
that the model accurately reflected the intended flap dimensions (see [Supplementary Video 1 ]). A 3D model was created for a patient undergoing hand contracture release, where
the defect was reconstructed using an anterolateral thigh (ALT) flap. The tissue paper
model was carefully contoured to the required dimensions, incorporating a multiple
Z-plasty design to ensure precise flap placement and optimal adaptation to the defect
site. Anatomical references play a crucial role in guiding the replication of anatomical
structures, ensuring that the tissue paper model closely mirrors the actual surgical
requirements, and aiding in planning an effective and aesthetically pleasing flap
design.
Video 1 The video demonstrates a novel technique utilizing tissue paper to create three-dimensional
(3D) models for visualizing tissue defects and planning flap reconstruction surgery.
The step-by-step process covers defect assessment, flap design, and model trimming,
highlighting the technique's effectiveness in preoperative planning and surgical education.
Step 1: Preparation of the Recipient Site
The recipient site was first prepared by cleaning and draping the area in a sterile
manner to ensure that the surrounding tissue was clearly visible and accessible for
flap design. The dimensions of the tissue defects were carefully measured and recorded,
including details such as defect depth, width, and any associated anatomical landmarks.
Step 2: Design of the Flap on Sterile Tissue Paper
A sheet of sterile tissue paper was placed over the recipient site. Using a sterile
surgical marker, the outline of the defect was traced directly onto tissue paper.
Additional anatomical landmarks were marked as needed to assist with flap orientation
and design. Tissue paper was used to design the proposed flap. The design considered
factors such as the size and location of the defect, tissue laxity, scar orientation,
and desired cosmetic outcome. The flap was outlined on tissue paper, and any necessary
adjustments were made to ensure that the tissue could be effectively mobilized, rotated,
or transposed to cover the defect. The flap was carefully removed from the tissue
paper using sterile surgical scissors.
Step 3: Adjusting the Tissue Paper Design to the Donor Site
The cut tissue paper model was placed over the recipient site to assess its fit and
make any necessary adjustments. The model was refined to accurately represent the
final design of the flap.
Step 4: Application of the Tissue Paper Model Flap to the Recipient Site
The tissue paper flap model was temporarily secured to the recipient site using sterile
adhesive tape. The model was then evaluated for its ability to adequately cover the
defect while maintaining a proper vascular supply and preserving the aesthetics of
the surrounding tissue. Adjustments were made as necessary to optimize the flap design.
Step 5: Final Assessment and Documentation
After the final adjustments, the tissue paper model was removed, and the design was
documented through photographs and detailed notes. The model provided a 3D representation
of the proposed flap, providing valuable insights into the feasibility and expected
outcomes of surgery. This method was repeated for each patient, with the tissue paper
model serving as the guide during flap surgery. The sterile tissue paper technique
is a simple, cost-effective, and highly adaptable approach for flap design, contributing
to improved surgical planning and outcomes.
Ethical Approval Statement
Ethical Approval Statement
This study was conducted in accordance with the ethical standards outlined in the
Declaration of Helsinki. Ethical approval for this research, involving three participants,
was obtained from the Fatmawati General Hospital Jakarta Ethic Committee-approved
protocol, and all participants provided informed consent before their participation.
Confidentiality and anonymity were maintained throughout the study, and participants
were informed of their right to withdraw from the study at any time without any consequences.
Informed Consent Statement
This research study involves the participation of human subjects. We would like to
inform all stakeholders that informed consent was obtained from the participants prior
to their involvement in the study. Three participants have voluntarily agreed to take
part in this research and have provided written consent after being fully informed
of the study's objectives, procedures, potential risks, and benefits. The participants
were assured that their participation was voluntary, and they had the right to withdraw
from the study at any time without any penalty. The confidentiality of all personal
data collected during this research will be maintained, and the results will be anonymized
to protect their identities. We confirm that all ethical standards for research involving
human subjects have been followed, and the consent obtained adheres to relevant institutional
guidelines and regulations.
Results
Preliminary applications of this technique have demonstrated its utility in the visualization
of complex tissue defects. Surgeons have successfully used tissue paper models for
preoperative planning to better understand the spatial relationships between structures.
Additionally, the models are effective educational tools for teaching medical students
and residents. The Spatial Analysis for Reconstruction Assessment (SARA) method is
regularly performed for free flap surgery in Fatmawati General Hospital, Jakarta,
by the authors, and has already been applied in more than 50 patients since 2022.
In this study, we presented only three patients who underwent defect reconstruction
with ALT free flap with complete intraoperative documentation. The first patient was
a 60-year-old male with squamous cell carcinoma excised from the left side of the
face ([Fig. 2 ]). The second patient shown here is a 35-year-old female with an irregular shape
defect after burn contracture excision (multiple W-plasty design) on lower right arm
and reconstructed with an ALT Flap ([Fig. 3 ]). The third patient was a 59-year-old man who had a sarcoma on his chest for 2 years.
Intraoperatively, the defect after tumor resection was circular with a diameter of
12.6 cm ([Fig. 4 ]).
Fig. 2 (A ) Defect after tumor removal. (B ) Precisely trimmed 3D tissue paper model aligned with the anatomical contours of
the defect. (C ) The anterolateral thigh is dissected, showing the vastus lateralis and rectus femoris
with the lateral circumflex femoral artery (LCFA) perforator spared. (D ) The 3D model was positioned on the donor site, and the specific shape was accurately
delineated. (E ) The ALT flap is harvested according to the shape of the 3D model, including the
vascular pedicle. (F ). The flap is inserted into the facial defect, and anastomoses connect the perforator
and its pedicle. 3D, three-dimensional.
Fig. 3 (A ) Irregular shape of burn contracture on the lower right arm. (B ) Tissue paper model with blood seepage to create the precision shape of the defect
after excision. (C ) Precisely trimmed 3D tissue paper model aligned with the anatomical contours of
the defect. (D ) The tissue paper model was placed on the ALT flap. (E ) ALT flap was harvested according to the shape of the 3D model, including the vascular
pedicle. (F ). The flap was inserted into the facial defect, and anastomoses were created to connect
the vascular pedicle to the recipient vessels to ensure adequate perfusion. ALT, anterolateral
thigh; 3D, three-dimensional.
Fig. 4 (A ) Defect after tumor removal. (B ) Precisely trimmed 3D tissue paper model aligned with the anatomical contours of
the defect. (C ) The ALT flap is harvested and divided into two parts to fit the shape of the 3D
model, including the vascular pedicle from the LCFA. (D ) The flap is inserted into the chest defect with anastomoses connecting the perforator
and its pedicle. LCFA, lateral circumflex femoral artery; 3D, three-dimensional.
Discussion
The use of tissue paper to create 3D models of tissue defects offers several advantages.
It is an inexpensive and accessible method that can be easily integrated into clinical
practice and education. The tactile nature of these models provides a unique advantage
over digital or purely visual methods, allowing users to physically manipulate and
explore their structures. However, this technique has limitations, including the potential
for less precise details compared to advanced imaging or 3D printing. Despite these
limitations, the proposed method serves as a valuable complementary tool in both educational
and clinical settings.
The use of tissue paper to create 3D models for defect measurement in flap surgery
offers substantial advantages that outweigh its inherent limitations. This method
is highly cost-effective and widely accessible, rendering it a practical tool for
both clinical applications and educational settings. The material's flexibility and
thin profile facilitate precise manipulation, allowing for accurate contouring to
replicate the anatomical dimensions of the defect. Moreover, the tactile feedback
provided by the physical model enhances the learning experience, offering hands-on
interaction that surpasses the capabilities of digital simulations. The simplicity
and efficiency of designing and shaping the tissue paper model enable rapid prototyping
of various flap designs, while the model itself serves as an effective visual aid.
This enhances the understanding of spatial relationships between the defect and surrounding
tissues, making it particularly valuable for educational purposes and surgical training
in flap design and tissue manipulation.
Although the tissue paper model used in our study features a thin texture, this characteristic
imparts flexibility, allowing surgeons to modify the model easily. Previous modalities
for free flap planning, such as 3D-printed models, have limitations in accounting
for flap thickness. Similarly, in the SARA method, the tissue paper model does not
inherently account for flap thickness. To address this limitation, we routinely estimate
flap thickness during our procedures. We typically perform primary thinning down to
the Scarpa fascia, leaving a 3-cm cuff of deep fat around the perforator. In cases
where tension persists, leaving 1 to 2 cm of the flap unsutured at the anastomosis
site can be beneficial. This approach allows for edema to resolve, facilitating a
tension-free secondary closure, which can typically be performed in a standard clinical
setting after approximately 2 weeks.
Despite certain limitations, such as the fragility of tissue paper and the absence
of feedback on critical parameters like vascular supply and tissue elasticity, these
drawbacks are generally manageable. The ease of use, combined with the enhanced visual
and spatial understanding provided by the models, makes this technique particularly
advantageous for preoperative planning and educational applications. While additional
care may be required to maintain sterility in surgical environments and precise scaling
for smaller or more complex defects can present challenges, these factors do not undermine
the overall utility of the method. Although the tissue paper models do not fully replicate
the texture or biomechanical properties of actual tissues, the method's affordability,
speed, and educational value establish it as a highly effective tool for surgical
planning and training in reconstructive procedures. Further research is needed to
refine the technique, address its limitations, and improve its precision. Incorporating
more accurate representations of tissue properties and developing models that simulate
real-time surgical conditions could greatly enhance its utility, transforming it into
an even more effective tool for preoperative planning, training, and education in
the medical field.
Conclusion
The SARA method of using tissue paper models for the 3D visualization of tissue defects
demonstrates considerable potential as a practical, cost-effective tool for enhancing
anatomical understanding and facilitating surgical planning. Its versatility and adaptability
make it especially valuable in both clinical and educational settings.
