Diagnostic imaging studies DIEP flap surgery
Question
Which diagnostic imaging studies are preferred for DIEP flap surgery?
Recommendation
CTA is the imaging study of choice for mapping perforators in DIEP flap breast reconstruction.
Only perform duplex-ultrasound or MRA if sufficient expertise is available.
Considerations
Color Duplex US
This method is suitable for mapping but highly dependent on the experience and skills of the technician, and can only be performed with sufficient quality in vascular labs or by specialized radiologists. Blood vessel properties, diameters and flow direction can be mapped with good discrimination between arteries and veins; however, the course through the rectus abdominis muscle usually cannot be identified.
These are long studies (1-2 hours), but are not invasive and pose no radiation burden.
These studies did not achieve the results of CTA and MRA: reduction in operating time and secondary reduction in postoperative complications.
CT angiography (CTA)
CT is a quick imaging study for mapping. The total duration is less than 20 minutes (scanning time: one breath-hold). Interobserver variability is low, provided that a good protocol is used (Mathes & Neligan, 2010). Intravenous iodinated contrast medium is necessary for this study, which allows visualization of the vascular tree from the origin of the internal iliac artery. Arterial phase scanning is required. For an optimal result, 3D maximum intensity projections (MIP) must be performed for the axial data in slices of 1-2 cm as a minimum. This allows assessment of the course of the perforators through the rectus abdominis muscle, their dominance, and thus their suitability (Kuekrek et al, 2011).
The average reduction in operative time and reduced postoperative complications are the result of more directed searching for the perforators, and enabling the surgeon to select one good, dominant perforator more reliably. Increased use of a perforator from the medial (rather than lateral) system reduces the occurrence of fat necrosis and damage to the intercostal nerves running to the rectus abdominis muscle (Ghattaura et al, 2010). This is also a major advantage for bilateral reconstructions.
Another advantage is that preoperative knowledge about the quality, location and course of the perforators can lead to a better treatment plan / dissection strategy (Mathes & Neligan, 2010; Casey et al, 2009; MinQiang et al, 2010). Imaging of venous branches is also possible, although contamination of the arterial vascular stem is possible, as a vein cannot always be distinguished from an artery. Rozen et al (2008) reported a 41% reduction in surgeon stress with preoperative use of CTA (p = 0.007).
Disadvantages are radiation and administration of iodinated contrast medium. Radiation burden, measured from 4 cm above the umbilicus to the origin of the DIEP flap from the external iliac artery, is 6-8 mSv on average for a modern multi-slice scanner (Ghattaura et al, 2010; Kuekrek, et al, 2011). This is a significant consideration, as the population in question is healthy. This may result in the popularity of MRA increasing. Potential complications of contrast agents are hypersensitivity and poor renal function, however, the effects are generally mild.
MR-Angiography (MRA)
MRA is also suitable for mapping. A 1.5 or 3 Tesla MRI is used, along with MRI contrast medium (gadolinium). The scan takes longer than CTA, with a higher risk of motion artifacts. Imaging of venous branches is more reliable than with CTA. Radiation burden is also avoided.
New technical developments lead to faster scanning times, down to 29 seconds (Chernyak et al, 2009). As is the case with CTA, the study can be performed within one breath-hold. It has a lower spatial resolution than CTA, but better contrast resolution.
In summary
The literature search identified a number of comparative studies of limited scientific value and with a low level of evidence. However, the studies did reveal important advantages for preoperative imaging studies prior to a DIEP procedure, primarily for CTA as the most studied imaging study. It has resulted in reduced operative time and postoperative flap and donor site complications. MRA is a promising technique, but little is yet known regarding reduction in operative time and complications.
Color Duplex US lacks the advantages of CTA and MRA, and remains a second option.
Evidence
Background
There is currently no consensus on which preoperative imaging technique is preferred prior to DIEP flap surgery. Mapping allows a standardized approach for assessment of vascular anatomy (Mathes & Neligan, 2010). This can be done with Color Duplex US, CTA and MRA.
Quality control requires description of the standard requirements that imaging techniques must fulfill and what the surgeon can expect from the studies.
Conclusions
a) Color Duplex-US versus CTA
|
Low (GRADE) |
Operative time
Preoperative mapping of perforators using CTA versus Color Duplex US appears to reduce operating time by at least one hour in unilateral reconstructions.
Sources (Gacto-Sanchez et al, 2010; Uppal et al, 2009; Smit et al, 2009) |
|
Very low (GRADE) |
Re-exploration, flap complications and donor site complications
The risk of re-exploration, flap complications and donor site complications appears to be lower if perforators are mapped preoperatively using CTA, instead of Color Duplex US.
Source (Gacto-Sanchez et al, 2010) |
|
very low (GRADE) |
Quality of perforator mapping (accuracy)
Perforator mapping appears to be more accurate if performed using CTA compared with Color Duplex US.
Sources (Cina et al, 2010; Scott et al, 2010) |
Literature summary
a) Color Duplex-US versus CTA
Five observational studies examined this question (Cina et al, 2010; Gacto-Sanchez et al, 2010; Scott et al, 2010; Smit et al, 2009; Uppal et al, 2009). The evidence tables are presented in the appendix to this chapter. The five studies compared the effects of preoperative perforator mapping using CTA versus Color Duplex US in patients with an indication for immediate or delayed autologous breast reconstruction.
Results
None of the studied outcome measures allowed pooling of results due to the clinical heterogeneity in study populations. Operative time Three studies examined this outcome measure (Uppal et al, 2009; Smit et al, 2009; Gacto-Sanchez et al, 2010) and found a statistically significant shorter operative time for patients with unilateral reconstructions in the CTA group. Reduction in operative time varied from at least one hour (Uppal et al, 2009; Smit et al, 2009) to over two hours (Gacto-Sanchez et al, 2010).
Re-exploration, flap complications and donor site complications
Gacto-Sanchez et al (2010) studied these outcome measures and found a statistically significant drop in re-explorations, flap complications and donor site complications in the group with a preoperative CTA. Smit et al (2009) only reported fewer complications in the CTA group.
Quality of perforator mapping (accuracy)
Two studies examined the accuracy of CTA and Color Duplex US (Cina et al, 2010; Scott et al, 2010). Cina et al (2010) found the Color Duplex US group showed an accuracy of 97%, with 90% of perforators proving viable during surgery. The accuracy of CTA was 91%, with 95% of perforators proving suitable for a DIEP flap. Scott et al (2010) found 94% of large perforators using CTA versus 62% with Color Duplex US. The authors did not report whether the results were statistically significant.
Level of evidence of the literature
The level of evidence for the outcome measure operative time is low, as the studies were not randomized in a patient group where multiple factors may have affected operating time (highly significant limitations in study design).
The level of evidence for the outcome measures re-exploration, flap complications and donor site complications is very low, as the studies were not randomized (highly significant limitations in study design) and the number of complications was low (imprecision).
The level of evidence for the quality outcome for perforator mapping (accuracy) using Color Duplex US is conflicting (heterogeneity). Additionally, there are limitations due to the non-randomized nature of the studies.
b) Color Duplex-US and MRA
No comparative studies examined this question.
c) CTA and MRA
No comparative studies examined this question.
Search and select
In order to answer the primary question, a systematic literature review was performed for the following question:
Is there a preference for Color Duplex US, CTA or MRA for preoperative mapping of perforators in patients who are scheduled for autologous breast reconstruction using a DIEP flap? The working group considered the following outcome measures to be relevant: aesthetic result, postoperative complications (partial flap necrosis; total flap necrosis; abdominal wall hernia), operative time and accuracy*.
Search and selection (Method)
Medline (OVID) was searched for studies on preoperative imaging studies in autologous breast reconstructions using a DIEP flap. The search justification is listed at the end of this chapter. The literature search yielded 225 results. Studies that met the following selection criteria were included in the literature summary: original studies; comparative studies; systematic review of comparative studies; comparison of Color Duplex US, CTA or MRA with each other; N>20; and at least one of the following outcome measures: aesthetic result, operating time or accuracy*.
* Quality can be assessed using accuracy: the number of perforators identified preoperatively divided by the number of perioperative perforators.
Five studies were included in the literature analysis (Cina et al, 2010; Gacto-Sanchez et al, 2010; Scott et al, 2010; Smit et al, 2009; Uppal et al, 2009). Two studies were excluded from analysis after reading the full article (Rozen et al, 2008; Chernyak et al, 2009). In the study by Rozen et al (2008), not all patients underwent the scheduled imaging studies. Chernyak et al (2009) did not compare different imaging studies with each other.
Methods
Authorization date and validity
Last review : 01-03-2015
Last authorization : 01-03-2015
Planned reassessment : 01-01-2019
The Board of the Dutch Society for Plastic and Reconstructive Surgery (NVPC) will assess whether this guideline is still up-to-date in 2018 at the latest. If necessary, a new working group will be appointed to revise the guideline. The guideline’s validity may lapse earlier if new developments demand revision at an earlier date.
As the holder of this guideline, the NVPC is chiefly responsible for keeping the guideline up to date. Other scientific organizations participating in the guideline or users of the guideline share the responsibility to inform the chiefly responsible party about relevant developments within their fields.
General details
Guideline development was funded by the Quality Fund for Medical Specialists (SKMS) and The Netherlands Organization for Health Research and Development (ZonMw).
Scope and target group
Guideline goal
To develop a multidisciplinary, evidence-based guideline for breast reconstruction in women undergoing breast conserving therapy or mastectomy for breast cancer, or following prophylactic mastectomy.
Guideline scope
The guideline focuses on all patients with an indication for breast reconstruction following breast conserving therapy or mastectomy. Additionally, the guideline may be applied to breast reconstruction in patients who have undergone surgical treatment for a benign breast condition. The guideline does not comment on the treatment of breast cancer. We refer the reader to the NABON guideline for the treatment of breast cancer (www.richtlijnendatabase.nl), which this guideline complements.
Unfortunately, circumstances did not permit a medical oncologist representing the NVMO to participate in the working group. Thus, the current version lacks a module on chemotherapy and breast reconstruction. The working group strives to create such a module for this guideline in the near future.
Intended audience for the guideline
The guideline aims to provide practical guidance for plastic surgeons and members of the multidisciplinary breast cancer team (surgical oncologist, medical oncologist, radiation oncologist, radiologist, pathologist, psychologist, breast care nurse specialist). A version for patients has recently been developed (https://www.b-bewust.nl/pif_borstreconstructie).
Samenstelling werkgroep
A multidisciplinary working group was appointed to develop the guideline in October 2011, consisting of representatives from all relevant specialties involved in the care for patients with breast reconstruction (see above for working group membership). Working group members were mandated by their professional organizations. The working group worked on developing the guideline for 2 years. The working group is responsible for the full text of this guideline.
- Dr. M.A.M. Mureau (President), MD, PhD, plastic surgeon, Erasmus MC Cancer Institute, Erasmus University Medical Center Rotterdam
- Professor Dr. R.R.W.J. van der Hulst, MD, PhD, plastic surgeon, Maastricht University Medical Center/Orbis Medical Center/Viecuri Medical Center, Maastricht
- Dr. L. A.E. Woerdeman, MD, PhD, plastic surgeon, Antoni van Leeuwenhoek / Netherlands Cancer Institute, Amsterdam
- Drs. A.A.W.M van Turnhout, MD, plastic surgeon, Tergooi Hospital, Hilversum Site
- N.A.S. Posch, MD, plastic surgeon, Haga Hospital, The Hague
- Dr. M.B.E. Menke-Pluijmers, MD, PhD, oncologic surgeon, Albert Schweitzer Hospital, Dordrecht
- Dr. E.J.T. Luiten, MD, PhD, oncologic surgeon, Amphia Hospital, Breda
- Drs. A.H. Westenberg, MD, radiotherapist/oncologist, Arnhem Radiotherapy Institute, Arnhem
- Dr. J.P. Gopie, PhD, psychologist, Leiden University Medical Center, Leiden
- Dr. H.M. Zonderland, MD, PhD, radiologist, Academic Medical Center, Amsterdam
- Drs. M. Westerhof, MSc, Netherlands Breast Cancer Association, Utrecht
- E.M.M. Krol-Warmerdam MA, V&VN Nurse Specialists, Leiden University Medical Center, Leiden
With support from
- Drs. B.S. Niël-Weise, MD, microbiologist / epidemiologist, senior advisor, Knowledge Institute for Medical Specialists
Declaration of interest
Working group members declared any (financial) ties with commercial companies, organizations or institutions involved in the field covered by the guideline for the past five years in writing. An overview is available on request from the office of the Knowledge Institute for Medical Specialists (KIMS).
Patient involvement
Patients are represented by a delegate from the Netherlands Breast Cancer Association in this guideline.
Method of development
Implementation
Guideline implementation and practical applicability of the recommendations was taken into consideration during various stages of guideline development. Factors that may promote or hinder implementation of the guideline in daily practice were given specific attention.
The guideline is distributed digitally among all relevant professional groups. The guideline can also be downloaded from the Dutch Society for Plastic and Reconstructive Surgery website: www.nvpc.nl, the guideline website: www.richtlijnendatabase.nl and the Quality Organization for Medical Specialists.
Methods and proces
AGREE
The guideline has been drafted in accordance with the requirements outlined in the ‘Guidelines 2.0’ report of the Guideline Advisory Committee of the Council on Science, Education and Quality (WOK). This report is based on the AGREE II instrument (Appraisal of Guidelines for Research & Evaluation II) (www.agreecollaboration.org), an instrument designed to assess the quality of guidelines with broad international support.
Primary questions and outcome measures
Based on the outcomes of the bottleneck analysis, the president and advisor formulated draft primary questions. These were discussed and defined together with the working group. Subsequently, the working group determined which outcome measures were relevant for the patient for each primary question, examining both desired and undesirable effects. The working group valuated these outcomes based on their relative importance as crucial, important and unimportant.
Literature search and selection strategy
Specific search terms were used to identify published scientific studies related to each individual primary question in Medline, Cochrane and, where necessary, Embase. Additionally, the references of the selected articles were screened for additional relevant studies. Studies offering the highest level of evidence were sought out first. Working group members selected articles identified by the search based on predetermined criteria. The selected articles were used to answer the primary question. The searched databases, the search string or terms used during the search and selection criteria applied are listed in the chapter for each individual primary question.
Quality assessment of individual studies
Individual studies were assessed systematically based on predefined methodological quality criteria in order to assess the risk of biased study results. These assessments may be found in the column ‘Study quality assessment’ in an evidence table.
Literature summary
The relevant study results from all selected articles were presented clearly in evidence tables. The key findings from the literature are described in the literature summary. If studies were sufficiently similar in design, data were also summarized quantitatively (meta-analysis) using Review Manager 5.
Assessment of the level of scientific evidence
A) With regard to intervention questions:
The level of scientific evidence was determined using the GRADE method. GRADE is short for ‘Grading Recommendations Assessment, Development and Evaluation’ (see http://www.gradeworkinggroup.org/) (Atkins et al, 2004).
B) With regard to questions about the value of diagnostic tests, harm or adverse effects, etiology and prognosis:
GRADE cannot be used (yet) for these types of questions. The level of evidence of the conclusion was determined based on the accepted EBRO method (van Everdingen et al, 2004).
Formulation of conclusions
With regard to questions about the value of diagnostic tests, harm or adverse effects, etiology and prognosis, the scientific evidence is summarized in one or more conclusions, listing the level of evidence for the most relevant data.
For interventions, the conclusion does not refer to one or more articles, but is drawn based on the body of evidence. The working group looked at the net benefits of each intervention. This was done by determining the balance between favorable and unfavorable effects for the patient.
Considerations
When making recommendations, scientific evidence was considered together with other key aspects, such as working group member expertise, patient preferences, costs, availability of facilities and/or organizational aspects. Insofar as they are not part of the systematic literature review, these aspects are listed under ‘Considerations’.
Formulation of recommendations
Recommendations provide an answer to the primary question, and are based on the best scientific evidence available and the most important considerations. The level of scientific evidence and the importance given to considerations by the working group jointly determine the strength of the recommendation. In accordance with the GRADE method, a low level of evidence for conclusions in the systematic literature review does not rule out a strong recommendation, while a high level of evidence may be accompanied by weak recommendations. The strength of the recommendation is always determined by weighing all relevant arguments.
Development of indicators
Along with developing a draft guideline, internal quality indicators were developed to allow monitoring of the implementation of the guideline in daily practice. More information about the method for indicator development may be requested from KIMS.
Knowledge gaps
During the development of this guideline, systematic searches were conducted for research contributing to answering the primary questions. For each primary question, the working group determined whether (additional) scientific research is desirable.
Commentary and authorization phase
The draft guideline was submitted to the (scientific) organizations involved for comment. The guideline was also submitted to the following organizations for comment: Netherlands Breast Cancer Association (BVN), Netherlands Society for Medical Oncology (NVMO), Dutch College of General Practitioners (NHG), Healthcare Insurers Netherlands (ZN), The Dutch Healthcare Authority (NZA), Health Care Insurance Board (CvZ), the Health Care Inspectorate (IGZ), Achmea, CZ, Menzis and VGZ. Comments were collected and discussed with the working group. The draft guideline was updated and finalized by the working group based on the comments. The final guideline was submitted for authorization to the (scientific) organizations involved and authorized by them.
Legal standing of guidelines
Guidelines are not legal prescriptions, but contain evidence-based insights and recommendations that care providers must meet in order to provide high quality care. As these recommendations are primarily based on ‘general evidence for optimal care for the average patient’, care providers may deviate from the guideline based on their professional autonomy when they deem it necessary for individual cases. Deviating from the guideline may even be necessary in some situations. If care providers choose to deviate from the guideline, this should be done in consultation with the patient, where relevant. Deviation from the guideline must always be justified and documented.