Coding System for Computed Tomographic Angiography of Inferior Epigastric Artery Perforators in DIEP Flaps
Bibliographic record
Abstract
Sir:FigureThe deep inferior epigastric perforator (DIEP) flap has become a widely used surgical technique for autologous breast reconstruction. The DIEP flap has proven reliability and a low complication rate, and preserves adequate abdominal wall competence.1 Because the anatomy of the cutaneous perforators of the anterior abdominal wall is variable,2 computed tomographic angiography contrast study of the abdominal wall is used preoperatively in many centers around the world to define the anatomy of deep inferior epigastric arteries and their perforators. Computed tomographic angiography is used for mapping the inferior epigastric vessels and perforators relative to landmarks on the abdominal wall. The technique provides a great deal of information to assist the surgeon elevating the DIEP flap and shortens operative time.3 A 54-year-old woman had previously undergone a left mastectomy and requested a prophylactic right skin-sparing mastectomy with bilateral DIEP flap breast reconstruction. The patient underwent preoperative computed tomographic angiography to elucidate the vascular supply of the anterior abdominal wall.4 Because it is time consuming to meet with the radiologist before each operation, we have devised a system whereby the radiologist can exactly specify the details of each perforator on the anterior abdominal wall and include this in the written report of the computed tomographic angiogram that is available electronically for the surgeon to review before surgery. The coding system involves two coordinates: Coordinate A: Perforators located to the left of the umbilicus will be marked by the letter (L), and any perforator located on the right of the umbilicus will be marked by (R) before writing the distance from the midline in millimeters. Coordinate B: Any perforator superior/cephalad to the umbilicus is marked by (-) and any perforator inferior/caudad to the umbilicus level is marked by (+); before writing the distance in millimeters from the umbilicus level. Usually we ignore the (+) mark. If the perforator is located on the umbilical level, we will refer to it with (0). After that we add the perforator caliber in millimeters. On the Doppler study and after starting the operation, it was obvious that the computed tomographic angiography results were correct and dependable, especially in describing the location of perforators and their courses (Fig. 1). The coding system makes it very simple and practical. Each perforator carries a unique code that defines its position and caliber (Table 1). The codes for the perforators of the case described above were as follows: (L50, 20, 1.7) (L15, 50, 1.2) (R36, 80, 0.6) (R36, 15, 0.9) (R60, 0, 1.7) (R60, -10, 1.1).Fig. 1: Grid on the anterior abdominal wall photograph preoperatively shows the accuracy of the study.Table 1: Codes of Perforators According to Computed Tomographic Angiography Finding*Dissection of the perforators in the abdominal wall is the most time-consuming part of DIEP flap surgery. The vascular anatomy of the skin has been studied previously5; however, preoperative determination of the exact anatomy of perforators of the anterior abdominal wall for DIEP flaps is a very helpful technique. The coding system for the perforators of the deep inferior epigastric artery can make the communication between the surgeons and radiologists simpler and the documentation easier. We believe it gives more confidence to surgeons before and during the procedure. Breast reconstruction using DIEP flaps can be achieved more safely. Ammar Al-Dhamin, M.B.Ch.B. Robert Berry, M.D. Vani Prasad, M.B.B.S. Alison Martin, B.Sc. Steven F. Morris, M.D., M.Sc. Departments of Surgery, Radiology, and Anatomy and Neurobiology, Dalhousie University, Halifax, Nova Scotia, Canada DISCLOSURE The authors have no financial disclosures, commercial associations, or conflicts of interest to report.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.003 | 0.003 |
| Bibliometrics | 0.006 | 0.002 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".