Latex-Infused Porcine Abdominal Model: A Novel Microsurgery Simulator for Deep Inferior Epigastric Perforator Dissection.

BACKGROUND: Perforator dissection and flap elevation are routinely performed for microsurgical reconstruction; however, there is a steep learning curve to mastering these technical skills. Though live porcine models have been utilized as a microsurgical training model, there are significant drawbacks that limit their use, including cost, limited ability for repetition, and obstacles associated with animal care. Here we describe the creation of a novel perforator dissection model using latex augmented non-living porcine abdominal walls. We provide anatomic measurements that demonstrate valuable similarities and differences to human anatomy to maximize microsurgical trainee practice. METHODS: Six latex-infused porcine abdomens were dissected based on the deep cranial epigastric artery (DCEA). Dissection was centered over the abdominal wall mid-segment between the second and fourth nipple line. Dissection steps included exposure of lateral and medial row perforators, incision of anterior rectus sheath with perforator dissection, and dissection of DCEA pedicle. DCEA pedicle and perforator measurements were compared with deep inferior epigastric artery (DIEA) data in the literature. RESULTS: An average of seven perforators were consistently identified within each flap. Assembly of the model was performed quickly and allowed for two training sessions per specimen. Porcine abdominal walls demonstrate similar DCEA pedicle (2.6 ± 0.21 mm) and perforator (1.0 ± 0.18 mm) size compared with a human's DIEA (2.7 ± 0.27 mm, 1.1 ± 0.85 mm). CONCLUSION: The latex-infused porcine abdominal model is a novel, realistic simulation for perforator dissection practice for microsurgical trainees. Impact on resident comfort and confidence within a microsurgical training course is forthcoming.

Inferior Epigastric Artery Pseudoaneurysm Following Laparoscopic Appendectomy.

An inferior epigastric artery pseudoaneurysm is an exceptionally rare occurrence. Formation of an inferior epigastric artery pseudoaneurysm can be seen following surgical intervention and is more common after laparoscopy. A sixty-eight-year-old male presented with a right upper quadrant bulge at his incision site two months following laparoscopic appendectomy. The patient reported sudden onset of a non-reducible bulge at a 5 mm trocar incision site with minimal pain and without obstructive symptoms. Computed tomography of his abdomen and pelvis with intravenous contrast revealed a 4.2 cm pseudoaneurysm with peripheral thrombosis within the right inferior epigastric artery. The patient subsequently underwent open exploration with the evacuation of pseudoaneurysm thrombus and ligation of arteriovenous fistula. The patient recovered well without complication from pseudoaneurysm. Inferior epigastric artery pseudoaneurysm following any laparoscopic procedure is rare. This case highlights the importance of understanding the abdominal wall anatomy and its vascular supply to avoid such injury. We present this case to bring light to this rare occurrence and to highlight the importance of proper trocar placement during any laparoscopic procedure.

Microsurgical phalloplasty: Anatomical study evaluating the use of the external pudendal vessels as recipients.

The inferior epigastric artery (IEA) is commonly used as a recipient vessel in microsurgical phalloplasty but its use can be associated with abdominal parietal complications (hernia, bulging). To preclude such complications and avoid involvement of the femoral artery, we assessed an external pudendal artery (EPA) as a recipient vessel. We studied the disposition of the external pudendal system and its general anatomy. Then we compared the external diameter of the EPA to that of the first branches of the femoral artery. The most important point was to determine the location of the EPA through a reference line to facilitate a surgical approach. We then illustrated this preliminary study with a clinical case to check the reliability of the identified landmarks. Ten adult cadavers were dissected. The arteries of interest were part of a system consisting of either a common trunk or a duplicated system. The branches of the pudendal system arose from either the femoral artery or the deep femoral artery. On a horizontal reference line passing through the two pubic tubercles, we observed that 83% of EPAs arose between the reference line and 3 cm below it, at the level of a vertical axis centered on the femoral artery. The EPA could be suitable as recipient vessel in phalloplasty owing to its location, size, and ease of dissection. Using it instead of the IEA precludes abdominal parietal complications and reduces scarring in the recipient area.

Revisiting the surgical anatomy of the triangle of doom and the triangle of pain.

Better understanding of the surgical anatomy of the triangle of doom and the triangle of pain with fixed bony landmarks like the anterior superior iliac spine (ASIS) and the pubic symphysis (PS) can help in defining a safe location for trocar placement during laparoscopic surgeries and minimize neurovascular complications. Ten cadavers were dissected bilaterally to explore the surgical anatomy of both the triangles. ASIS and PS were evaluated in relation to the deep inguinal ring, external iliac artery, femoral nerve, and inferior epigastric artery. The deep inguinal ring was located at a depth of ~3 cm, about 4.9 ± 0.56 cm along the y-axis and 6.2 ± 0.94 cm along the x-axis, from the ASIS. The external iliac artery was located ~4.33 ± 0.6 cm along the y-axis and 7.29 ± 0.76 along the x-axis from the ASIS. The inferior epigastric artery was at ~4.31 ± 0.38 cm from the midline at the level of ASIS. This knowledge can help in the surface localization of both the triangles and prevent injury to the various neurovascular structures in relation to these triangles. In the current study, cranial to the ASIS lying at a distance of >5 cm from the midline was observed to be a safe zone for accessory trocar placement. The umbilical port has been observed to be safe for trocar placement. The mean angle between ductus deferens and testicular vessels was observed to be 43.5° ± 4.79°, which could help in determining their relative locations during various surgical procedures.

Intramuscular Deep Inferior Epigastric Vessels Are Insulated by Perimysial Fibroadipose Tissue Network.

BACKGROUND: The difficulty of elevating a deep inferior epigastric perforator (DIEP) flap largely depends on the intramuscular course of the vessel and the perforator. Previous studies, however, have lacked histologic descriptions of the vessels and surrounding structures. The present study analyzed the histologic aspects of the deep inferior epigastric vessels and perforators, focusing on their perivascular relationships with muscle fibers. METHODS: The abdomen of a cadaver was histologically evaluated to identify intramuscular deep inferior epigastric vessels. Tissue samples were stained with hematoxylin and eosin and with Masson trichrome stain to visualize fibrous components. Twenty-one DIEPs from 12 patients were also evaluated to determine the histologic aspects of the perivascular structure. In the cross-section of each perforator and adjacent tissue, the perforator-to-muscle distance and trichrome-stained area were measured, and the correlation of the perforator size with the perforator-to-muscle distance and the percent collagenous portion of the distance were determined. RESULTS: Histologic analysis showed that the deep inferior epigastric vessels and perforators were encased by perimysial connective tissue and were not in direct contact with the muscle fibers. The smaller perimysia branched out from the larger perimysia, forming an interconnecting network structure. Correlation analysis showed that larger vessels had more collagenous portions in the perimysial structures (Spearman's ρ = 0.537, p = 0.012). CONCLUSION: The deep inferior epigastric vessels and perforators reside in a perimysial fibroadipose tissue network. This may provide surgeons with a microscopic perspective during DIEP dissections. Having an idea of the perforator anatomy in microscopic level can help us to perform safer perforator dissections.

Anatomical study and clinical importance of the inferior epigastric artery / Estudio anatómico e importancia clínica de la arteria epigástrica inferior

SUMMARY: The inferior epigastric artery (IEA) is a major blood vessel that supplies the anterior abdominal wall. The aim of the current study was to provide clinicians, surgeons, and obstetricians with sufficient anatomical data on the inferior epigastric artery, such as its origin and branching pattern. The study included 20 embalmed cadavers, these cadavers were dissected, and the inferior epigastric artery and vena comitans/venae comitantes were identified and traced downwards to the external iliac vessels. The origins, caliber, course and pedicle length of both the artery and the vein(s) were studied. The inferior epigastric artery arose independently from the distal external iliac artery deep to the inguinal ligament in 19 (95 %) cadavers. The artery entered the rectus abdominis muscle at its middle third in 13 (65 %) cases and at its lower third in the remaining specimens. In this study, we found that the artery divided into two branches in 18 (90 %) of the cases; in the remaining two cases, it continued as one trunk. The average pedicle length was 7.2 cm. The mean caliber of the IEA was 3.7 mm. In 18 (90 %) dissections, the venous drainage consisted of a pair of venae comitantes that united to form a common vessel at their draining point on the external iliac vein. The average diameter was 3.9 mm. The current study focuses on the anatomical features of the inferior epigastric artery to increase the success rate of abdominal and pelvic operations in clinical practice.

RESUMEN: La arteria epigástrica inferior (AEI) es un vaso sanguíneo principal que irriga la pared abdominal anterior. El objetivo del presente estudio fue proporcionar a los médicos, cirujanos y obstetras suficientes datos anatómicos sobre la arteria epigástrica inferior, como su origen y patrón de ramificación. El estudio incluyó 20 cadáveres embalsamados, los que se disecaron y se identificó la arteria epigástrica inferior y la vena concomitante y se siguieron hasta los vasos ilíacos externos. Se estudiaron los orígenes, calibre, trayecto y longitud del pedículo tanto de la arteria como de la (s) vena (s). La arteria epigástrica inferior surgió independientemente de la arteria ilíaca externa profunda al ligamento inguinal en 19 (95 %) cadáveres. La arteria ingresó al músculo recto del abdomen en su tercio medio en 13 (65 %) casos y en su tercio inferior en las muestras restantes. En este estudio, encontramos que la arteria se dividió en dos ramas en 18 (90 %) de los casos; en los dos casos restantes, continuó como un tronco. La longitud media del pedículo fue de 7,2 cm. El calibre medio del AEI fue de 3,7 mm. En 18 (90 %) disecciones, el drenaje venoso consistió en un par de venas concomitantes las que formaron un vaso común en su punto de drenaje en la vena ilíaca externa. El diámetro medio fue de 3,9 mm. El estudio actual se centra en las características anatómicas de la arteria epigástrica inferior con el propósito de mejorar la tasa de éxito de las cirugías abdominales y pélvicas en la práctica clínica.

Arterial anatomy of the anterior abdominal wall: Ultrasound evaluation as a real-time guide to percutaneous instrumentation.

INTRODUCTION: Instrumenting the anterior abdominal wall carries a potential for vascular trauma. We previously assessed the presence, position, and size of the anterior abdominal wall superior and inferior (deep) epigastric arteries with computed tomography (CT). We now present a study using ultrasound (US) assessment of these arteries, to evaluate its use for real time guidance of percutaneous procedures involving the rectus sheath. MATERIALS AND METHODS: Twenty-four participants (mean age 67.9 ± 9 years, 15 M:9 F [62:38%]) were assessed with US at three axial planes on the anterior abdominal wall: transpyloric plane (TPP), umbilicus, and anterior superior iliac spine (ASIS). RESULTS: An artery was visible least frequently at the TPP (62.5 - 45.8%), compared with the umbilicus (95.8-100%) and ASIS (100%), on the left, χ2 (2) = 20.571; p < .001, and right, χ2 (2) = 27.842; p < .001, with a moderate strength association (Cramer's V = 0.535 [left] and 0.622 [right]). Arteries were most commonly observed within the rectus abdominis muscle at the level of the TPP and umbilicus, but posterior to the muscle at the level of the ASIS (95.8-100%). As with the CT study, the inferior epigastric artery was observed to be larger in diameter, start more laterally, and move medially as it coursed superiorly. CONCLUSIONS: These data corroborate our previous results and suggest that the safest level to instrument the rectus sheath (with respect to vascular anatomy) is at the TPP. Such information may be particularly relevant to anesthetists performing rectus sheath block and surgeons during laparoscopic port insertion.

Differences of the midline-crossing venous drainage pattern in supraumbilical and infraumbilical regions: Angiographic study using fresh cadavers.

Current clinical and anatomical studies show that the venous problem associated with the deep inferior epigastric perforator flap results from poor midline-crossing. We examined the venous anatomy of the infraumbilical midline area and the dynamic venous flow of the deep inferior epigastric perforator flap in nine fresh cadavers. All nine abdominal specimens were harvested between the subcostal margin and the groin crease. Two specimens were used to analyze the abdominal venous anatomy, one of which was divided into two hemi-abdominal specimens. The remaining seven specimens were harvested as deep inferior epigastric perforator flaps with one major paraumbilical perforator. Venous cannulation and serial angiographic agent injection were performed in several conditions. Each specimen was radiographed using a soft X-ray system. For additional information, computed tomography (CT) angiography-visualized superficial inferior epigastric veins (SIEVs) and the supraumbilical branch were analyzed. We noted that the venous drainage between the bilateral SIEVs was easier to configure in the supraumbilical area than in the infraumbilical area. Only one to two short polygonal venous networks connect the bilateral superficial inferior epigastric veins in the supraumbilical area; however, long and multiple polygonal venous networks connect the bilateral superficial inferior epigastric veins in the infraumbilical area, which could be a predisposing factor for venous congestion. The mean distance from the umbilicus upper border to evident supraumbilical midline crossover was 18.39±4.03 mm (range: 10.10-28.49) in CT angiograms. In cadaver specimens, the mean distance was 10.87±4.85 mm (range: 4.6-18.9). Supraumbilical midline crossover was more favorable than infraumbilical midline crossover in venous flow.

Refining our knowledge of macrovascular arteriovenous shunts (MAS): Anatomical and pathological studies.

BACKGROUND: The macrovascular arteriovenous shunt (MAS) connecting the deep inferior epigastric artery (DIEA) and superficial inferior epigastric vein (SIEV) in the abdominal wall has already been identified as an important structure, and further study has been deemed necessary to establish its role and function. METHODS: Review of CT angiograms (CTA) of 38 female patients was undertaken, by means of analysis of fine-cut axial images and three-dimensional image reconstructions of the cutaneous vasculature of the deep and superficial vasculature. In vivo dissection of the structure was also performed to establish its communications. Lastly, a histopathological analysis was carried out to investigate its intrinsic structure and function. RESULTS: The MAS was identified in both sides of the abdomen in all subjects and the diameter ranges from 0.72 to 2.81 mm with a median diameter of 1.28 mm. In vivo dissection revealed it as a distinct structure connecting the DIEA and SIEV. Pathological analysis showed that it has characteristics of both elastic and muscular arteries, which constitutes a new vessel. CONCLUSION: These further investigations have yielded a better understanding of the MAS shunt, its position, structure and function. This can be of crucial importance to reconstructive surgeons when raising the DIEP flap.

Anatomy of the arterial and venous systems of the superficial inferior epigastric artery flap: A retrospective study based on computed tomographic angiography.

BACKGROUND: This study was performed to investigate the arterial and venous anatomy of superficial inferior epigastric artery (SIEA) flaps using multidetector-row computed tomography angiography (MDCTA). We hypothesized that applicability of the SIEA flap has been underestimated in previous studies. METHODS: We retrospectively analyzed the results of preoperative MDCTA of the bilateral lower abdominal walls in 72 consecutive patients. We assessed the presence and branching pattern of the superficial inferior epigastric artery, superficial inferior epigastric vein (SIEV), superficial circumflex iliac vein, and venae comitantes (VC) of the superficial inferior epigastric artery. We also assessed the internal diameter of the SIEA at its origin. RESULTS: The SIEA was present on 133 sides (92.4%), and the mean internal diameter was 2.0 mm. The internal diameter of the SIEA was ≥2.0 mm on 102 sides (70.8%). The VC drained into the superficial circumflex iliac vein on 68 sides (47.2%) and to the SIEV on 30 sides (20.8%). CONCLUSIONS: An internal diameter of the SIEA of ≥2.0 mm at its origin on preoperative imaging can be a good criterion for exploring the artery during lower abdominal flap harvest. The VC is the dominant drainage vein over the SIEV in some patients, and it communicates with the superficial circumflex iliac vein in almost half of patients. These findings can increase the safety of breast reconstruction with an SIEA flap.

Intraoperative Observation during Total Extraperitoneal Repair (TEP).

We aim to observe and dissect the essential anatomical landmarks in totally extraperitoneal (TEP) procedures. Forty-six TEP procedures in 30 patients were prospectively performed in our department. During the dissection of the preperitoneal space, the following distances between landmarks were measured. D1: the distance from pubic symphysis to the arcuate line in the midline; D2: the distance from the inferior epigastric artery to the lateral border of the arcuate line (before sharp incision was performed); D3: as in D2 (but after sharp incision was performed); D4: the distance from the inferior epigastric artery to the crossing site of vas deferens and obliterated umbilical artery. Furthermore, the morphology of the posterior rectus sheath was documented. The corresponding distance between the anatomical landmarks varied greatly in each individual. D1: 8 ± 1.6 cm (range 4-10 cm). D2: 4.9 ± 0.8 cm (3.5-7 cm). D3: 6.8 ± 0.9 cm (5-9 cm). D4: 6.1 ± 1 cm (4.8-8.5 cm). Complete rectus sheath was found in 30.4 per cent (14/46) of the hernias. Anatomical variations were common in preperitoneal space. The crossing site of vas deferens and obliterated umbilical artery can serve as a landmark for dissection. Complete rectus was present in one-third of hernias, which necessitates a sharp incision for entering the correct lateral preperitoneal space.

An anatomic study of deep inferior epigastric artery diameters at the origin from external iliac and at the lateral border of rectus abdominis muscle by computed tomographic angiography from autologous breast reconstruction patients.

BACKGROUND: Autologous breast reconstruction by means of microsurgical abdominal flaps is an very well described technique. The flap harvest dissection under inguinal ligament would cause the risk of parietal weakening in this zone and postoperative bulging. The goal of our study is to investigate whether the deep inferior epigastric artery diameter remains constant from its exit of the external iliac artery to its entrance in the rectus muscle sheath. PATIENTS AND METHOD: One hundred arteries were studied on fifty preoperative computed tomographic angiographies made before a DIEAP flap for breast reconstruction. We measured the caliber of the left and right deep inferior epigastric arteries at these two landmarks. The length of this artery between these was also calculated. This data were collected with specific angiography reconstruction. RESULTS: At the caudal landmark, the mean DIEA diameter was 2.1±0.27mm on the left side and 2.1±0.31mm on the right side. At the cephalic landmark, the mean DIEA diameter was 2.0±0.28mm on the left and 2.0±0.27mm on the right side (P=0.00035 at left side; P=0.0089 at right side). The mean pedicle length between the two landmarks was 22.3±2.85mm on the left side and 22.2±2.98mm on the right side. CONCLUSION: This computed tomographic angiography study showed that the diameter of DIEA is equivalent at its origin and at the lateral border of muscle. Flap harvest without dissection under inguinal ligament provides sufficient pedicle length and caliber to allow for comfortable and reliable sutures.

[To harvest a SIEA flap instead of a DIEP flap in breast reconstruction: A technical note]. / Prélever un SIEP à la place d'un DIEP en reconstruction mammaire : note technique.

Breast reconstruction by abdominal flap has evolved to ensure minimal donor-site morbidity with the description of Deep Inferior Epigastric artery Perforator flap (DIEP flap). Being of the same thickness and the same surface, the Superficial Inferior Epigastric Artery flap (SIEA flap) does not require, for it harvesting, to open the abdominal fascia or to dissect through the muscles minimizing again donor-site sequelae. However, it is little used because of the variability of its vascularization and a higher failure rate than the DIEP in the literature. We believe that it is reasonable, in some cases, to harvest a SIEA flap instead of DIEP flap in mammary reconstruction. We present a technical note explaining our operative strategy for reliably taking a SIEA when the caliber of the vessels allows.

Ex vivo radiocontrast description of the caudal epigastric arteries in horses.

OBJECTIVE: To determine the location of the deep and superficial caudal epigastric arteries in relation to 3 midline positions and the relationship between the location of these arteries, body circumference, and body condition score. STUDY DESIGN: Descriptive anatomical study. SAMPLE POPULATION: Nine horses, aged 1-28 years (mean 10.61 ± 8.89 SD). METHODS: Body condition score and body circumference were measured prior to euthanasia. Angiographic studies of the deep and superficial caudal epigastric arteries were performed on resected abdominal walls. The distances between the deep and the superficial caudal epigastric arteries and 3 midline positions were measured. Correlations among these distances, body circumference, and body condition score were analyzed. RESULTS: The location of the deep caudal epigastric artery correlated with body circumference and body condition score at the umbilicus (r = 0.53 and 0.68, respectively), midpoint landmark (r = 0.79 and 0.83, respectively), and prepubic tendon attachment (r = 0.69 and 0.78, respectively). The course of this artery could be estimated by multiplying body circumference by 0.04 ± 0.02 at the umbilicus, 0.07 ± 0.01 at the midpoint landmark, and 0.03 ± 0.015 at the prepubic tendon attachment. The course of the superficial caudal epigastric artery did not correlate with anatomic landmarks. CONCLUSION: The course of the deep caudal epigastric artery could be estimated at 3 midline landmarks on the basis of body circumference and body condition score in equine cadavers. CLINICAL SIGNIFICANCE: Predicting the course of the caudal epigastric arteries in the equine abdomen based on correlation among location, body circumference, and body condition score may prevent iatrogenic damage during creation of laparoscopic portals.

Lymph nodes around the posterior gastric artery: their existence, frequency, and clinical implications.

PURPOSE: The lymphatic flow along the posterior gastric artery (PGA) is considered of possible clinical importance in terms of lymphatic metastasis; however, little is known about the lymph nodes (LNs) around this artery. The purpose of this study was to establish if LNs exist around the PGA and to evaluate their clinical implications. METHODS: We examined the tissues surrounding the PGA from 21 cadavers to search for LNs. We also investigated the patterns of lymphatic metastases in patients who underwent surgery for gastric neoplasms at our institute to detect their presence along the PGA. RESULTS: The PGA was identified in 11 cadavers, and LNs around the PGA were detected microscopically in 2 of these. Lymphatic metastasis directly to the LNs at the splenic artery without any metastases was regarded as skip metastasis along the PGA. Skip metastasis was found in two of ten patients who underwent surgery for remnant gastric cancer. CONCLUSIONS: The existence of LNs around the PGA was confirmed, and based on our findings, lymphatic metastasis through the PGA is possible in patients with remnant gastric cancer.