Deep inferior epigastric perforator flap: An anatomic study of the perforators

Journal of military pharmaco-medicine no5-2018<br /> <br /> DEEP INFERIOR EPIGASTRIC PERFORATOR FLAP: AN<br /> ANATOMICAL STUDY OF THE PERFORATORS<br /> Nguyen Van Phung*; Tran Van Anh**; Vu Quang Vinh**<br /> SUMMARY<br /> Objectives: Deep inferior epigastric artery perforator flaps have become popular worldwide in<br /> breast reconstruction to reduce done site morbidity. Isolating perforator vessels challenges most<br /> surgeons. The purpose of study was to investigate anatomical vascular of the deep inferior<br /> epigastric perforator flap. Subjects and methods: 40 flaps were harvested from 20 fresh adult<br /> cadavers. The deep inferior epigastric artery and its perforators were dissected and canularized.<br /> Barium sulfate 30% v/w diluted and mixed with blue methylen was injected. Determine details<br /> such as perforator size, location and measurements in relation to the umbilicus. Results: 177<br /> perforator vessels dissected from 40 flaps, average 4.4/1 flap. 106 perforators (59,9%) in a<br /> medial row with 84 perforators (79,3%) were oblique course. 71 perforators (40,1%) in a lateral<br /> row with 51 perforators (71,8%) were rectilinear course. 111 perforators (63,7%) located in a<br /> distance of 10 - 40 mm from the umbilicus. The average length and diameter of the dominant<br /> perforators was 44.3 ± 13.8 mm and 1 ± 0.1 mm. Conclusion: Understanding the morphological<br /> characteristics of the perforator can aid the surgeon in more harvesting safety the deep inferior<br /> epigastric artery perforator flap. Two vertical rows of perforator vessels were observed along the<br /> anterior rectus abdominal sheath: medial row and lateral row. The perforator presents a rectilinear<br /> course usually was in lateral row and easy to dissect than the perforator presents an oblique<br /> course. The dominant perforators usually located in a distance of 15 - 40 mm from the umbilicus.<br /> * Keywords: Deep inferior epigastric perforator flap; Breast reconstruction.<br /> <br /> INTRODUCTION<br /> The deep inferior epigastric perforator<br /> (DIEP) flap is one of the most commonly<br /> flaps that was used for reconstruction in<br /> plastic surgery due to excellent quality,<br /> adequate tissue and soft texture. Especially,<br /> middle-aged breast cancer patients usually<br /> have excess skin and belly fat that will be<br /> suitable materials for breast reconstrucition.<br /> In recent decades, the development of<br /> DIEP flap has brought new modifications<br /> to the conventional abdominal flaps due to<br /> less donor-site morbidity and total muscular<br /> preservation. The DIEP flap could decrease<br /> <br /> abdominal bulging or muscular weakness.<br /> In addition, the DIEP flap dissected from<br /> the rectus abdominis, can increase in pedicle<br /> length, which allows better freedom of design.<br /> However, identifying the deep inferior<br /> epigastric artery (DIEA) and vein is still<br /> challenging the surgeons because of variable<br /> anatomy of blood vessels in human<br /> bodies. Our research aims to: Study on<br /> the anatomical characteristics of the inferior<br /> arteries that give blood supply for DIEP<br /> flat in adult Vietnamese cadavers, that<br /> could give useful informations for plastic<br /> surgeons in clinical practice.<br /> <br /> * Hochiminh University of Medicine and Pharmacy<br /> Corresponding author: Nguyen Van Phung (ngvaph@cyd.edu.vn)<br /> Date received: 10/03/2018<br /> Date accepted: 21/05/2018<br /> <br /> 143<br /> <br /> Journal of military pharmaco-medicine no5-2018<br /> SUBJECTS AND METHODS<br /> 1. Subjects.<br /> This research was carried out on 20<br /> adult Vietnamese cadavers in Department<br /> of<br /> Anatomy, Hochiminh University from<br /> November 2011 to Juanuary 2016.<br /> 2. Methods.<br /> The descriptive cross-sectional study.<br /> - A 4 cm inguinal incision was made to<br /> explore deep epigastric artery. The catheter<br /> was inserted to artery to inject contrast<br /> agent (barium sulfate 30%) and blue<br /> methylen. 24 hours later, we performed<br /> surgery to dissect rhombus flap in abdominal<br /> wall from umbilicus to anterior superior<br /> iliac spine. These flaps were dissected to<br /> superficial fascia membranous layer<br /> (Scarpa’s fascia) to explore perforator<br /> arteries under medical loupes (x3 - 5).<br /> After that, we opened the anterior wall of<br /> rectus sheath and muscle to identify DIEA.<br /> - We determined orginin, branches,<br /> diameter, length of deep epigastric inferior<br /> arteries and deep epigastric perforator<br /> arteries. We also recorded the course of<br /> these arteries.<br /> - Gross photo and X-ray were taken in<br /> all cases.<br /> - We analyzed data by statistical software.<br /> RESULTS<br /> 1. Deep inferior epigastric artery<br /> perforator.<br /> The DIEA was recognized on both<br /> sides of 20 human cadavers and the orgin<br /> was a single branch from the external iliac<br /> artery. It curved forward in the subperitoneal<br /> 144<br /> <br /> tissue, and then ascended obliquely along<br /> the medial margin of the abdominal<br /> inguinal ring; continuing its course upward,<br /> it pierced the transversalis fascia and<br /> passed in front of the linea semicircularis,<br /> ascended between the rectus abdominis<br /> and the posterior lamella of its sheath<br /> (31/40). The other ateries entered in rectus<br /> abdominis muscle (9/40). We found the<br /> DIEA divided into 2 main branches in 17<br /> cases, 3 main branches in 2 cases. The<br /> other cases had only 1 main branch.<br /> The average diameter of DIEA at the<br /> orgin was 2.2 ± 0.2 mm and at the lateral<br /> boder of the rectus abdominis was 1.9 ±<br /> 0.2 mm.<br /> The average length of DIEA from the<br /> orgin and the lateral boder of the rectus<br /> abdominis to the perforator arteries was<br /> 14.9 ± 3.5 cm and 10.9 ± 1.1 cm, respectively.<br /> 39 cases had 2 veins that went along<br /> with DIEA and 1 case had 1 vein. All these<br /> veins drained to the external iliac vein.<br /> 2. The perforators.<br /> In this research, we studied the perforator<br /> that ≥ 0.5 mm of diameter in rhombus flap.<br /> * Number:<br /> There were 177 perforators which divived<br /> from 40 orversed DIEA (4.4 perforators per<br /> DIEA). The average number of perforators<br /> of DIEA that had 1 main branch and<br /> 2 main branches were 4.33 and 4.18,<br /> respectively. In the DIEA that had 2 main<br /> branches, the average number of perforators<br /> of lateral branch and medial branch were<br /> 2.0 and 2.12, respectively. In 2 cases of<br /> the DIEA that had 3 main branches, they<br /> had 3 and 4 perforators.<br /> <br /> Journal of military pharmaco-medicine no5-2018<br /> * Location and distribution:<br /> In front of retus sheath, the perforators<br /> were distributed in 2 lines: the lateral line<br /> in lateral one-third of restus abdominis<br /> muscle and the medial line in the medial<br /> one-third of restus abdominis muscle.<br /> There were 106 perforators (59.9%) in the<br /> medial line and 71 perforators (40.1%) in<br /> the lateral line, of which the number of<br /> dominant perforators in each line were 24<br /> (60%) and 16 (40%).<br /> <br /> If the umbilicus was the O-axis of the<br /> XY axis, the average distance from the<br /> perforators to the X-axis was 23.8 ± 15.8<br /> mm, the Y axis was 22.5 ± 12 mm. The<br /> average distance from the most dominant<br /> perforator to the X axis was 16.2 ± 7.1 mm,<br /> while the Y axis was 23.4 ± 13.1 mm.<br /> Within the circle of the center of the<br /> umbilicus, the distribution of the perforators<br /> and dominant perforators as shown in<br /> table 1:<br /> <br /> Table 1: Distribution of perforators in scope the bottom half of circle, of which the<br /> center was umbilicus.<br /> 0 - 2 cm<br /> <br /> < 2 - 4 cm<br /> <br /> < 4 - 6 cm<br /> <br /> < 6 - 8 cm<br /> <br /> Number of perforators (n = 177)<br /> <br /> 55 (31.1)<br /> <br /> 56 (31.6%)<br /> <br /> 52 (29.4%)<br /> <br /> 14 (7.9%)<br /> <br /> Number of dominant perforators (n = 40)<br /> <br /> 16 (40%)<br /> <br /> 13 (32.5%)<br /> <br /> 11 (27.5%)<br /> <br /> 0 (0%)<br /> <br /> The average distance from perforators to umbilicus was 34.4 ± 17.2. Most of the<br /> perforators were within 10 - 40 mm from the umbilicus.<br /> <br /> Figure 1: The perforators of DIEA - cadaver number 476.<br /> * Length and diameter:<br /> In the study, we measured the diameters of the perforators at the origin and the length<br /> of the perforators from the point of origin to the point of entry into the superficial fascia.<br /> 145<br /> <br /> Journal of military pharmaco-medicine no5-2018<br /> Table 2: The size of the perforators.<br /> <br /> Average diameter<br /> Average length<br /> <br /> Perforators<br /> with diameters<br /> ≥ 0.5 mm<br /> (n = 177)<br /> <br /> Dominant<br /> perforators<br /> (n = 40)<br /> <br /> 0.7 ± 0.2<br /> <br /> 1 ± 0.1<br /> <br /> 45.8 ± 11.8<br /> <br /> 44.3 ± 13.8<br /> <br /> Most perforators had relatively short<br /> length, including the dominant perforators.<br /> The diameter of the perforators was quite<br /> small, with most of the perforators less<br /> than 1 mm in diameter. Therefore, it was<br /> difficult to directly use these perforators<br /> for<br /> the<br /> flap’s<br /> blood<br /> supply<br /> in<br /> supermicrosurgery. It could be required to<br /> use DIEA together.<br /> <br /> was rectilinear course and<br /> (42.5%) was oblique course.<br /> <br /> with 17<br /> <br /> * The characteristics of perforator in Xray:<br /> The skin flaps were X-rayed and the<br /> results showed that the blood supply to<br /> the flap was plentiful, with connections<br /> between the perforators. The blood<br /> supply area of each perforator was<br /> dependent on its diameter at the enter<br /> point of muscle fascia.<br /> <br /> * The course of perforators:<br /> The course of perforators before<br /> entering the superficial fascia was recored<br /> in two different forms. The first form, a<br /> direction of perforator was perpendicular<br /> to the distance from the origin to skin flap.<br /> For this form, when dissecting to isolate<br /> the perforator, we only need to seperate<br /> along them without removing muscle, and<br /> distance from the flap to DIEA is shorter.<br /> The second form, from the origin of<br /> perforators with cross direction through<br /> muscle to skin flap, it could be outward,<br /> inward, downward, or upward. Muscle<br /> could be removed when dissecting the<br /> cross croner perforator because the<br /> distance is longer. The perforators in a<br /> medial line with 21 (19.8%) was rectilinear<br /> course and with 84 (79.3%) was oblique<br /> course. The perforators in a lateral line<br /> with 51 (71.8%) was rectilinear course<br /> and with 20 (28.2%) was oblique course.<br /> The dominant perforators with 23 (57.5%)<br /> 146<br /> <br /> Figure 2: The perforators on X-ray Cadaver 482.<br /> DISCUSSION<br /> Breast reconstruction following breast<br /> cancer surgery is a necessity for patients<br /> to improve the quality of life. The suitable<br /> breast reconstruction material is always a<br /> challenge in clinical study that requires to<br /> find a material that adequately meets the<br /> regenerative volume, closely relates to<br /> the opposite breast and the least affects<br /> tissue supply. The DIEP flap is the skin<br /> flap that fully filled the above criteria. It<br /> was applied clinically by Koshima and<br /> Seoda in 1989 firstly. After that, Allen<br /> used this flap for breast reconstruction in<br /> 1994. Nowadays, DIEP has been used<br /> more and more commonly in breast<br /> reconstruction [1, 2, 7]..<br /> <br /> Journal of military pharmaco-medicine no5-2018<br /> Despite of many advantages of breast<br /> reconstruction, the application of DIEP<br /> flap in clinical remains difficult for surgeons<br /> due to abnormalities and differences in<br /> anatomy such as the course of the DIEA<br /> and its perforators, causes obstacles to lift<br /> safely. Thus, studying the DIEA and its<br /> perforators has always been interesting [5,<br /> 8, 9]. There were many studies on this<br /> issue, but the results were not consistent.<br /> According to Itoh, Boyd, Tansatit, ElMrakby... the DIEA was divided into 2<br /> branches in most of cases [3, 4, 6, 11].<br /> Meanwhile, according to Nguyen Tran<br /> Quynh, the DIEA was not divided into 2<br /> branches but ran straight up in the form of<br /> a main body in most of cases. In our<br /> study, 52.5% of the cases of DIEA were<br /> main body type, which ran up, 47.5% of<br /> the cases of DIEA divided into 2 - 3<br /> branches.<br /> The number of perforators per DIEA<br /> was also reported differently by many<br /> authors, depending on how large or short<br /> perforators were determined by the<br /> diameter of the perforators included in the<br /> study, the number of perforators of DIEA<br /> for abdominal intervals from 0.8 to 6.8. In<br /> our study, examined perforators with<br /> diameter of ≥ 0.5 mm were found with an<br /> average of 4.4 peforator per DIEA. Itoh<br /> and Boyd also examined perforators with<br /> diameter of ≥ 0.5 mm but within the<br /> umbilicus region with an average of 6.5<br /> and 6.8 perforators per DIEA. In<br /> agreement with the other authors, we<br /> found that the perforators were distributed<br /> in two lines at the entry point of the rectus<br /> abdominis: medial and lateral, with 106<br /> <br /> (59.9%) and 71 (40.1%), respectively.<br /> When osbserving the direction of<br /> perforators, we found that perforators in<br /> the medial rows were often oblique<br /> course in the muscle (79.3%), while in the<br /> lateral rows were often rectilinear course<br /> (71.8 %), which was consistent with other<br /> authors' reports. This was a feature that<br /> should be noted for the selection of<br /> perforators when lifting the flaps. For the<br /> perpendicular perforator, we only need to<br /> seperate along them without removing<br /> muscle. Muscle could be removed when<br /> dissecting the cross croner peforator<br /> because the distance was longer.<br /> When studying the distance betwwen<br /> the entry point of the perforators at the<br /> superficial fascia and the umbilicus, we<br /> found that the most perforators (62.7%)<br /> were located within a radius of 0 - 40 mm<br /> with the center of umbilicus, which was<br /> consistent with the other authors. The<br /> dominant perforator was also concentrated<br /> in a radius of 0 - 40 mm with the center of<br /> umbilicus (72.5%). The most dominant<br /> perforator in our study had an average<br /> diameter of 1 ± 0.1 mm (0.8 - 1.2 mm),<br /> with an average length of 44.3 ± 13.8 mm.<br /> The length from the starting position of the<br /> most dominant perforator to the DIEA at<br /> the lateral rectus abdominis was 10.9 ± 1.1.<br /> CONCLUSION<br /> The perforators were in 2 lines along<br /> the anterior rectus abdominal sheath: medial<br /> and lateral. The perforator presents a<br /> rectilinear course usually was in lateral<br /> row and easy to dissect than the perforator<br /> presents an oblique course. The dominant<br /> 147<br /> <br />