Topography of inferior epigastric artery relevant to laparoscopy: a CT angiographic study

Purpose

The incidence of inferior epigastric artery (IEA) injury is 0.2–2 %. The aim of this study was to trace the position and course of the inferior epigastric artery in the anterior abdominal wall above the inguinal ligament at three important landmarks, i.e., at the mid-inguinal point, Anterior Superior Iliac Spine (ASIS) and umbilicus in abdominal CT Angiograms. The study also correlates the relationship of body build and the position of the inferior epigastric artery.

Methods

In 50 CT Abdominal angiograms, the course of the inferior epigastric artery was traced and distance between the artery and midline was measured at the above landmarks using measurement tool on the picture archival and communication system. The measurements were analyzed using SPSS version 16 and expressed as mean and standard deviation. Mann–Whitney test was used to compare the mean values and ratios in males and females. Linear regression was done to derive formulas by which the position of the inferior epigastric artery could be found.

Results

The mean distance of the inferior epigastric artery from the midline was 5.17 ± 0.93 cm at the level of mid-inguinal point, 4.57 ± 1.05 cm at the level of ASIS and 5.27 ± 1.17 cm at the level of umbilicus. There was a definitive predictive pattern in the course of the artery as seen in correlation and regression analysis.

Conclusion

The security distance for safe trocar placement was 6 cm at the level of ASIS and 9 cm at the level of umbilicus. Preoperative IEA assessment is helpful in reducing injuries to IEA.

     

以腹壁下血管为蒂设计的肌皮瓣

在34侧成人标本上,观测了腹壁下血管。由腹壁下动脉发出的肌皮支在前部形成内外两列、上下4～5排的血管束,在脐周围呈放射状分布。腹壁下动脉上部的肌皮支穿过腹直肌鞘后走向外上方,指向肩胛骨下角。腹壁下血管与其他分布至腹前外侧壁的血管呈分层吻合,以此为基础可设计多种肌皮瓣。     

Morphometrical study of the arterial perforators of the deep inferior epigastric perforator flap

Although abdominal perforator flaps based on a cutaneous branch of the deep inferior epigastric artery (DIEP flaps) have many advantages, preparing these flaps is technically difficult and requires great skill, especially as the portion of the artery running under the anterior rectus abdominis sheath must be operated upon "blind". To allow easier preparation and elevation of a DIEP flap pedicle, we propose that the arterial perforator should: 1) be more than 1.0 mm large; 2) run a straight intramuscular course, parallel to the rectus abdominis m. fibers, with no large muscular branches; and 3) have only a short portion running immediately under the anterior rectus abdominis sheath. We examined 329 perforators (more than 0.5 mm in diameter at the anterior sheath) in 66 rectus abdominis mm. from 33 cadavers among them: 1) 52 "large" perforators were over 1.0 mm in diameter; 2) 107 "suitable" perforators ran parallel to the muscle fibers without giving off large muscular branches; and 3) 35 "ideal" perforators combined these characteristics. The ideal perforators were usually located in the mid-abdominal region, 10-30 mm lateral to the umbilicus. The suitable perforators were usually present, often in combination with the ideal perforator(s), in a restricted area 20 mm cranial and 40-50 mm lateral to the umbilicus. We classified the course and ramification pattern of the deep inferior epigastric a. into six patterns, depending on whether the anastomosis was sited in the medial or lateral branch and the level at which the branches originated.     

Morphometrical study of the arterial perforators of the deep inferior epigastric perforator flap

Abstract: Although abdominal perforator flaps based on a cutaneous branch of the deep inferior epigastric artery (DIEP flaps) have many advantages, preparing these flaps is technically difficult and requires great skill, especially as the portion of the artery running under the anterior rectus abdominis sheath must be operated upon “blind”. To allow easier preparation and elevation of a DIEP flap pedicle, we propose that the arterial perforator should: 1) be more than 1.0 mm large; 2) run a straight intramuscular course, parallel to the rectus abdominis m. fibers, with no large muscular branches; and 3) have only a short portion running immediately under the anterior rectus abdominis sheath. We examined 329 perforators (more than 0.5 mm in diameter at the anterior sheath) in 66 rectus abdominis mm. from 33 cadavers among them: 1) 52 “large” perforators were over 1.0 mm in diameter; 2) 107 “suitable” perforators ran parallel to the muscle fibers without giving off large muscular branches; and 3) 35 “ideal” perforators combined these characteristics. The ideal perforators were usually located in the mid-abdominal region, 10-30 mm lateral to the umbilicus. The suitable perforators were usually present, often in combination with the ideal perforator(s), in a restricted area 20 mm cranial and 40-50 mm lateral to the umbilicus. We classified the course and ramification pattern of the deep inferior epigastric a. into six patterns, depending on whether the anastomosis was sited in the medial or lateral branch and the level at which the branches originated.     

胎儿腹前壁的解剖观察

对44例妊娠3个月至足月胎儿尸体腹前壁标本,在解剖显微镜下进行了解剖观察。胎儿腹前壁的腱膜都是双层结构,每一个腹直肌鞘的前、后壁由3层腱膜组成。6层腱膜全部是斜行的,在正中线附近,两侧腱膜相互交叉编织,形成下列延续关系,即两侧腹外斜肌的2层腱膜,两侧腹横肌的2层腱膜,一侧内斜肌的腱膜与对侧外斜肌腱膜(深层)和腹横肌腱膜(前层)。此外,脐以下的部分腹横肌腱膜纤维穿过同侧腹内斜肌腱膜,与外斜肌腱膜纤维融合。脐环处还有少量纤维束附于脐索的深筋膜上。本文观察表明,腹前壁扁肌腱膜的再分层及其规则排列,在胎儿时期即已形成,这对增加腹壁的弹性和韧性,并利于腹直肌在鞘内的收缩活动具有重要功能意义。     

Locating the arcuate line of Douglas: Is it of surgical relevance?

Ventral hernia formation is a common complication of rectus abdominis musculocutaneous flap harvest. The site and extent of harvest of the flap are known contributing factors. Therefore, an accurate location of the arcuate line of Douglas, which marks the lower extent of the posterior wall of the rectus sheath, may be relevant before harvesting the flap. This study is aimed at determining the position of the arcuate line in relation to anatomical landmarks of the anterior abdominal wall. Arcuate lines were examined in 80 (44 male, 36 female) subjects, aged between 18 and 70 years, during autopsies and dissection. The position of the arcuate line was determined in relation to the umbilicus, pubic symphysis, and intersections of rectus abdominis muscle. Sixty four (80.4%) cases had the arcuate line. In most cases (52), this line was located in the upper half of a line between the umbilicus and the pubic symphysis. Most males (93%) had the arcuate line, while more than a third of females did not have it. In all these cases, the line occurred bilaterally as a single arcade, constantly at the most distal intersection of the rectus abdominis muscle. Consequently, the arcuate line is most reliably marked superficially by the distal tendinous intersection of the rectus abdominis muscle. Harvesting of the muscle cranial to this point will minimize defects in the anterior abdominal wall that may lead to hernia formation. Clin. Anat. 23:84–86, 2010. © 2009 Wiley‐Liss, Inc.     

男性单侧腹直肌罕见缺失变异1例

目的 报道1例罕见的右侧腹直肌完全缺失并不伴有其他器官系统变异尸体的腹部解剖过程,腹壁肌群及其供血情况。 方法 解剖并观察尸体腹壁肌、血供、神经支配,对比两侧腹直肌发育和形态差异。 结果 该尸体右侧腹直肌缺失,腹直肌鞘完好,腹壁上动脉和腹壁下动脉仍在腹直肌鞘内走行并相吻合,肋间神经及肋下神经（T7～T12）由鞘内穿出达皮下。左侧腹直肌发育正常并有代偿性增生。男尸腹壁未见疤痕和手术切痕,腹内器官无缺失,腹膜除肝区外无黏连。 结论 该尸体右侧腹直肌缺失可能是胚胎发育第6周之前出现异常所导致。目前腹直肌肌皮瓣常用于多项外科重建手术,全面了解腹直肌的相关变异,对于扩展重建手术的应用范围和作好术前准备,确保手术成功均具有指导意义。     

Incisional/ventral herniorrhaphy employing bilateral reversed anterior rectus abdominis sheath

Repair of a symptomatic incisional/ventral hernia that is not amenable to simple primary closure is problematic. Therapeutic options include: (1) fascial reapproximation after unilateral/bilateral horizontal parasagittal relaxing incisions (obliquus externusand transversus abdominis) with or without pre-operative pneumoperitoneum; (2) bridging a fascial defect with autologous devascularized (lata femoris, anterior rectus abdominissheath) or vascularized (abdominal wall fascia, tensor fasciae latae, myofascial, or myofascial/cutaneous rotational flaps) tissue; or (3) insertion of prosthetic/synthetic material (polypropylene, polytetrafluoroethylene, polygalactin). In the presence of abdominal infection or contaminated operative wounds use of autologous tissue is preferred, because of the risks of infection and gastroenterocolonic fistulization. Since 1985 the authors have observed excellent results with use of a bilateral reversed anterior rectus abdominissheath technique of incisional/ventral herniorrhaphy. Although the parasagittal incision parallel to the linea semilunarisand mobilization medially undoubtedly caused partial devascularization (interruption of segmental and intermuscular arteriovenous arcades, respectively), the sheath coapted in the midline maintained its integrity as evaluated clinically and radiographically. This implies that the Sheath is relatively hypometabolic, that collateral circulation is maintained and/or develops, and/or sustenance is obtained by contiguity with peritoneal secretions and subcutaneous tissue. Twenty-three patients (13 males, 10 females, age range 19–79 years) with large symptomatic mid-abdominal hernias of 8–16 months duration were so treated. Each of these patients had required multiple (three to seven) exploratory celiotomies for traumatic, infectious, inflammatory., or neoplastic entities. To date all patients have healed per primumwithout recurrence. Only one patient, who had previously received pelvic irradiation, manifested eventration. This qualitative analysis suggests that this technique has validity for patients requiring incisional/ventral herniorrhaphy with an otherwise intact rectus abdominismuscle and sheath. © 1994 Wiley-Liss, Inc.     

The effect of anterior abdominal wall scars on the vascular anatomy of the abdominal wall: A cadaveric and clinical study with clinical implications

The anterior abdominal wall integument is frequently used in a range of reconstructive flaps. These tissues are supplied by the deep and superficial inferior epigastric arteries (DIEA and SIEAs) and the deep and superficial superior epigastric arteries (DSEA and SSEAs). Previous abdominal wall surgery alters this vascular anatomy and may influence flap design. One hundred and sixty‐eight patients underwent abdominal wall computed tomographic angiography (CTA) for preoperative imaging. Fifty‐eight of these patients had undergone previous abdominal surgery, and were assessed for scar pattern and relationship to the course and distribution of all major axial vessels and perforators. Two cadaveric abdominal wall specimens with midline abdominal scars underwent contrast injection of the DIEAs and DSEAs, with subsequent CTA. The course and distribution of all cutaneous vessels were assessed. In all clinical and cadaveric cases, the vasculature of the abdominal wall had been altered by previous surgery. In the clinical cases, vascular architecture was universally altered in the region of the scar, often modifying the filling patterns of the abdominal wall and occasionally precluding the use of an abdominal wall flap. In both cadaveric specimens, regions of non‐filling were evident upon contrast injection, highlighting the angiosomes not supplied by the DIEA or DSEA. Previous abdominal wall surgery necessarily alters the vascular architecture of the abdominal wall, and may alter the source vessels supplying cutaneous tissues. CTA was useful in identifying and delineating these changes, and may be used as a preoperative tool in this role. Clin. Anat. 22:815–822, 2009. © 2009 Wiley‐Liss, Inc.     

The anterior abdominal fat body

The anterior abdominal fat body is a mixture of multilocular and unilocular fat cells. It is found deep to the rectus sheath and immediately beneath the peritoneum of the anterior abdominal wall. It is first seen in the sixth month fetus as thin lobules of tissue arranged on either side of the umbilical vein but receiving blood supply from specific ensiform branches of the superior epigastric or internal thoracic artery and vein. Continued growth results in a coalescence of the bilateral lobules into a single fat body that completely overgrows the supportive blood vessels. In its cytology this body is comparable to the interscapular fat pad. It is unique in that vascular connections develop between it and the liver and in the fact that in a significant number of specimens it attains proportions that appear to represent pathological hypertrophy.     

Development of the rectus abdominis and its sheath in the human fetus

Purpose: Although the rectus abdominis and its sheath are well known structures, their development in the human fetus is poorly understood. Materials and Methods: We examined rectus abdominis and sheath development in semiserial horizontal sections of 18 fetuses at 5-9 weeks of gestation. Results: Rectus muscle differentiation was found to commence above the umbilicus at 6 weeks and extend inferiorly. Until closure of the anterior chest wall via fusion of the bilateral sternal anlagen (at 7 weeks), the anterior rectal sheath originated from the external oblique and developed towards the medial margin of the rectus abdominis at all levels, including the supracostal part. After formation of the anterior sheath, fascial laminae from the internal oblique and transversus abdominis contributed to formation of the posterior rectus sheath. However, the posterior sheath was absent along the supracostal part of the rectus abdominis, as the transversus muscle fibers reached the sternum or the midline area. Therefore, it appeared that resolution of the physiological umbilical hernia (8-9 weeks) as well as chest wall closure was not required for development of the rectus abdominis and its sheath. Conversely, in the inferior part of the two largest fetal specimens, after resolution of the hernia, the posterior sheath underwent secondary disappearance, possibly due to changes in mechanical stress. Conclusion: Upward extension of the rectus abdominis suddenly stopped at the margin of the inferiorly developing pectoralis major without facing the external intercostalis. The rectus thoracis, if present, might correspond to the pectoralis.     

Anatomic guidelines for the prevention of abdominal wall hematoma induced by trocar placement

A knowledge of the parietal structures of the abdominal wall is necessary to minimize risks of operative procedures like laparoscopy. For means to prevent intraoperative bleeding and the occurrence of abdominal wall hematoma, we studied the course of the inferior epigastric arteries and the ascending branch of the deep circumflex iliac artery in 21 human cadavers. The abdominal wall structures were dissected and the distances of the arteries in relation to anatomic structures such as the umbilicus, pubic symphysis, superior ischial spine and lower edge of the rib-cage were measured. Comparison of the morphometric results obtained with the location of 36 trocar incision sites recommended in the common literature yields the information that about half of these incision sites incur the risk of injuring the arteries.     

Mushroom cloud appearance of hemorrhage into the superficial anterior abdominal wall associated with an underlying rectus sheath hematoma

We present a case of rectus sheath hematoma compounded by anterior abdominal wall haemorrhage. Its clinical and anatomical relationship is discussed.     

Development of the ventral body wall in the human embryo

Migratory failure of somitic cells is the commonest explanation for ventral body wall defects. However, the embryo increases ~ 25‐fold in volume in the period that the ventral body wall forms, so that differential growth may, instead, account for the observed changes in topography. Human embryos between 4 and 10 weeks of development were studied, using amira ^® reconstruction and cinema 4D^® remodeling software for visualization. Initially, vertebrae and ribs had formed medially, and primordia of sternum and hypaxial flank muscle primordium laterally in the body wall at Carnegie Stage (CS)15 (5.5 weeks). The next week, ribs and muscle primordium expanded in ventrolateral direction only. At CS18 (6.5 weeks), separate intercostal and abdominal wall muscles differentiated, and ribs, sterna, and muscles began to expand ventromedially and caudally, with the bilateral sternal bars fusing in the midline after CS20 (7 weeks) and the rectus muscles reaching the umbilicus at CS23 (8 weeks). The near‐constant absolute distance between both rectus muscles and approximately fivefold decline of this distance relative to body circumference between 6 and 10 weeks identified dorsoventral growth in the dorsal body wall as determinant of the ‘closure’ of the ventral body wall. Concomitant with the straightening of the embryonic body axis after the 6th week, the abdominal muscles expanded ventrally and caudally to form the infraumbilical body wall. Our data, therefore, show that the ventral body wall is formed by differential dorsoventral growth in the dorsal part of the body.     

Factors influencing the diameter of human anterior and posterior intercostal arteries

At present, there have not been any detailed studies examining the size relationships of the intercostal arteries. This study was carried out to investigate the relationship between the vessel lumenal diameter of ipsilateral, paired anterior and posterior IC arteries, as well as with the length of the IC space supplied by each artery. Samples were collected from the second‐sixth anterior and posterior IC arteries near their site of origin, and the lengths of the corresponding IC spaces were measured in 42 cadavers. Lumenal diameters of both the anterior and posterior IC arteries at consecutive IC space closely followed second degree polynomial regression models (R² = 0.9655, and R² = 0.9741, respectively), and reached maximum size at the fifth IC space, which was found to be the longest of the IC spaces. No direct relationship was observed between diameters of the paired anterior and posterior IC arteries, although there was a trend for the larger anterior IC arteries to be paired with the larger posterior IC arteries. The calculated rate of blood flow at each IC artery was approximately two‐fold greater in males than in females. These results suggest that the length of the IC space, and hence the extent of the thoracic wall supplied, is a major factor in determining the diameter of both anterior and posterior IC arteries. Since COPD is such a prevalent disease, this study also examined its influence on the IC arteries, and found that the posterior IC arteries are significantly larger among afflicted subjects. Clin. Anat. 28:219–226, 2015. © 2014 Wiley Periodicals, Inc.     

Arterial Wall Adaptation under Elevated Longitudinal Stretch in Organ Culture

Arteries in vivo are subjected to large longitudinal stretch which may change significantly due to vascular disease and surgery. However, little is known about the effect of longitudinal stretch on vascular function and wall remodeling, although the effects of tensile and shear stress from blood pressure and flow have been well documented. To study the effect of longitudinal stretch on vascular function and wall remodeling, porcine carotid arteries were longitudinally stretched 20% more than in vivo for 5 days while being maintained in an ex vivo organ culture system under conditions of pulsatile flow at physiologic pressure. Vessel viability was demonstrated by strong vasomotor responses to norepinephrine (NE, 10^-6M), carbachol (10^-6M), and sodium nitroprusside (10^-5M), as well as by dense staining for mitochondrial activity and a low occurrence of cell necrosis. Cell proliferation was examined by incorporation of bromodeoxyuridine (BrdU). Results showed that arteries maintain normal structure and viability after 5 days in organ culture. Both the stretched and control arteries demonstrated significant contractile responses. For example, both stretched and control arteries showed approximately 10% diameter contraction in response to NE. Stretched arteries contained 8% BrdU-positive cells compared to 5% in controls (p < 0.05). These results indicate that longitudinal stretch promotes cell proliferation in arteries while maintaining arterial function. © 2003 Biomedical Engineering Society. PAC2003: 8719Rr, 8717Ee, 8719Uv     

A Reevaluation of the Unusual Abdominal Musculature of Squamate Reptiles (Reptilia: Squamata)

The abdominal muscles of lizards and snakes (Squamata) have been the subject of periodic attention from anatomists, embryologists, and systematists. Until now, the presence of a superficial portion of the m. rectus abdominis, named the m. rectus abdominis lateralis, has been considered a key synapomorphy of the clade Autarchoglossa, which includes all extant squamates save Gekkota and Iguania. However, the precise anatomical relations of the m. rectus abdominis lateralis have never been fully investigated. Here, I show that the m. rectus abdominis lateralis is present in Iguania. Its absence in Gekkota represents rare gross anatomical support for recent molecular‐structure‐based hypotheses of squamate relationships placing geckoes as sister to the remaining squamates. Where present, it is the most superficial trunk muscle, exterior to the m. obliquus externus. The separation of the m. rectus abdominis lateralis from the m. rectus abdominis occurs as the m. obliquus externus aponeurosis and part of the m. obliquus internus aponeurosis emerge superficially to form the outer portion of the rectus sheath. In Autarchoglossa, the contralateral mm. recti abdomines laterales meet at the midline and are attached to the imbricae of the transverse scale rows characteristic of the clade, suggesting developmental, functional, and evolutionary association. Because the m. rectus abdominis lateralis is sometimes continuous with the pectoralis, its exclusive association with the m. rectus abdominis is questionable. It may be a neomorphic layer that is part of the abaxial developmental system, comprising those muscles whose connective tissue is largely derived from lateral plate as opposed to somatic mesoderm. Anat Rec, 292:1154–1161, 2009. © 2009 Wiley‐Liss, Inc.