PDF-962.pdf 420 | Miscellaneous A New Anatomical and Surgical Landmark in Internal Abdominal Oblique Muscle Fat Triangle Kazem Madaen,1 Behrooz Niknafs2 Purpose: To determine the anatomical landmark within the internal oblique muscle. Materials and Methods: - - ratomy. Results: There was a fat line at anterior superior iliac spine level to access the underlying layers and then to the abdominal cavity. Conclusion: A fat triangle within the internal oblique muscle provides a suit- able region of surgical incision at the lower part of the abdominal wall. Keywords: abdominal muscles, abdominal wall, adult, diagnosis Corresponding Author: Behrooz Niknafs, Anatomical PhD Department of Anatomical Sci- ences, School of Medical Sciences, Tabriz University of Medical Sci- ences, Tabriz, Iran Tel: +98 411 386 2062 Fax: +98 411 334 2086 E-mail: niknafsbeh@yahoo.com Received April 2011 Accepted August 2011 1 Department of Urology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran 2 Department of Anatomical Sci- ences, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran Miscellaneous 421Vol. 9 | No. 1 | Winter 2012 |U R O LO G Y J O U R N A L Landmark in Internal Oblique Muscle | Madaen and Niknafs INTRODUCTION nternal oblique muscle is one of the abdomi- nal layers, which is located deep to the exter- nal oblique muscle, and leads to intra-abdom- inal cavity. The internal oblique muscle must be incised to approach the abdominal cavity either through intra-peritoneal or retro-peritoneal spac- es. Repair of the abdominal wall is important after a put little or no emphasis on a landmark or a par- ticular region for incision through the internal oblique muscle.(1-4) The incision must be made the nerves and vessels. The aim of this study was to determine the ana- tomical landmark within the internal oblique mus- site is an easy way to go underneath the abdomi- nal layers and can be used in different surgical applications. This landmark can be used in the re- pairs and incisions of the internal oblique muscle with little damage. MATERIALS AND METHODS The abdominal wall was exposed by dissection - verse or para-umbilical incisions were made on 1/4 of the lower anterior abdominal wall at the - nal oblique aponeurosis were incised on the line - cle was dissected easily through the fat triangle. Deep to the fat triangle, the transverse abdominis and other layers were incised to approach abdom- inal cavity. The margins of the fat triangle were ligated after completing the surgery. The surgical dissection exposed the underlying internal oblique muscle, which was precisely studied. RESULTS Within the internal oblique muscle, a fat line was - ing layers and then to the abdominal cavity. The border of the rectus abdominis sheath in a trian- gle shape. The base of the fat triangle was located adjacent to the lateral border of the sheath. The fat triangle was observed on both the left and right sides of the subjects. The width and size of the fat triangle were more prominent in obese patients than the thin ones. Furthermore, no blood vessels and nerves were DISCUSSION internal oblique muscle as a new landmark. This triangle can be recognized by bony landmark at - out any severe damage to the abdominal wall. To the best of our knowledge, the fat triangle as anatomical or surgical landmark has not been ad- dressed previously. This anatomical landmark has attracted more attention from surgeons than Figure 1. Anterior abdominal wall showing the external surface of internal oblique muscles. The fat triangle is seen at the ante- rior superior iliac spine level. 422 | Miscellaneous anatomists. According to insertion point of the muscle, the internal oblique muscle can be divided into three parts; cranial, middle, and caudal parts. The cra- nial part is inserted into the inferior border of the last three ribs. The middle part continues trans- versally and medially to become aponeurotic, and then reach the linea alba. The caudal part ends on inguinal ligament.(5) was constructed by a space between the caudal and middle parts of the internal oblique muscle, - - nal oblique muscle. There are three requirements for proper abdomi- nal incision: 1) accessibility; 2) extensibility; and 3) security. The incision should be long and wide enough for a good exposure.(6) This fat triangle has enough length and provides safe dissection plan. Furthermore, surgeons must take care to than transect them.(6) This splitting can be done abdominal wall consists of eight layers, below the - cal preparations and repairs. The fat triangle as a critical guidance might prevent the damage to the layers.(2) Since the fat triangle was devoid of any nerves and blood vessels, it was supposed to be an ap- propriate region to cut the muscle and get to the deep layers without any damage to the nerves. For instance, the iliohypogastric nerve innervates caudal part of the internal oblique muscle except cremasteric part.(3) Surgical care must be taken not to sever the nerve as this causes motor paralysis in the segments of the abdominal muscle that they innervate, and subsequently weakness in the ab- dominal wall. Therefore, manipulating the fat tri- angle was safe to sever the probable nerves. CONCLUSION We concluded that the fat triangle within the in- ternal oblique muscle as a landmark provides a good region of surgical incision at lower part of - ing, and no vessels and nerves injury. Further- more, the surgical approach is easy through the internal oblique muscle. CONFLICT OF INTEREST None declared. REFERENCES 1. Healy JC, Borley NR. Aboman and Pelvis In: Standring S, ed. Gray’s anatomy: The anatomical basis of clinical practice. 39 ed. London: Eleseveir Inc; 2005:1108-9. 2. Ramasastry SS, Futrell JW. Surgical anatomy of the internal oblique muscle: a practical approach. Am Surg. 1987;53:278- 81. 3. Yang D, Morris SF, Geddes CR, Tang M. Neurovascular ter- ritories of the external and internal oblique muscles. Plast Reconstr Surg. 2003;112:1591-5. 4. Mahadevan V. Anatomy of the anterior abdominal wall and groin. Surgery (Oxford). 2006;24:221-3. 5. Platzer W. Locomotor system In: Kahle W, Leonhardt H, Platzer W, eds. Color Atlas and Textbook of Human Anatomy. Vol 1. 3 ed. New York: Thieme; 1986:86-7. 6. Skandalakis JE, Skandalakis PN, Skandalakis LJ. Surgical Anatomy and technique: a pocket manual. 2 ed: Springer Verlag; 2000:156-63. Figure 2. Sche- matic illustration of the position of the fat triangle. IO indicates internal oblique muscle; and TA, transversus abdominis.