The splenic artery, also known as the lienal artery, is the largest branch of the celiac trunk in adults [1]. It follows a characteristically tortuous course along the superior border of the pancreas, within the splenorenal ligament, to the hilum of the spleen [2]. Throughout its journey, it provides critical vascular supply not only to the spleen but also to adjacent structures including the stomach, pancreas, and greater omentum via its numerous branches [3]. Historically, the spleen was misconceived as a vestigial organ, leading to its routine removal even for minor injuries [4]. This perception shifted dramatically following the seminal work of Morris and Bullock, which established the life-threatening risk of overwhelming post-splenectomy infection (OPSI), highlighting the spleen's essential role in immunological defence and the filtration of senescent blood cells [5]. This pivotal understanding spurred the development of spleen-preserving surgical techniques, making the detailed knowledge of splenic vascular anatomy more critical than ever [6].In contemporary practice, the management of splenic trauma and pathologies like hypersplenism, thrombocytopenia, and aneurysms has evolved towards minimally invasive approaches. Non-operative management (NOM), splenic artery embolization, and laparoscopic splenectomy have become the standard of care, necessitating a precise understanding of the splenic artery's anatomy to avoid complications and preserve splenic function where possible [7, 8]. Furthermore, advancements in non-invasive diagnostic imaging, such as computed tomography (CT) and colour Doppler ultrasonography, have improved the preoperative detection of vascular variations and pathologies, allowing for better surgical planning[9,10]. However, the splenic artery is renowned for its significant anatomical variability in origin, course, and branching pattern [11, 12]. These variations pose a substantial challenge during upper abdominal surgeries and interventional radiological procedures. For instance, a retropancreatic course can obscure the artery during dissection, and an unrecognized polar artery can be a source of significant haemorrhage if accidentally transected [13,14]. Despite the existing body of literature, population-specific data remains valuable due to potential ethnic and geographical variations in vascular anatomy. Therefore, the present study was undertaken to conduct a detailed anatomical dissection of the splenic artery in 30 human cadavers to elucidate its origin, course, branching pattern, and terminal distribution. The findings aim to contribute a valuable morphological database that can aid in refining surgical and radiological techniques, ultimately improving patient outcomes.

This study was designed as a descriptive, cross-sectional observational study conducted in the Department of Anatomy, a design commonly employed in detailed morphological research [15]. The investigation was carried out over a two-year period, from 2012 to 2014, utilizing a sample of thirty adult human cadavers of mixed sexes. All cadavers were obtained from the institutional cadaveric program and were properly embalmed using a standard formalin-based preservative solution to ensure adequate fixation and long-term preservation for anatomical study, thereby maintaining the structural integrity of the vasculature [16].The primary materials for the dissection included a standard set of surgical instruments, comprising toothed forceps, blunt forceps, pointed forceps, and scissors. To enhance the visibility of the delicate vascular structures for documentation, a specific set of materials for painting was employed, a technique adapted from previous anatomical studies to improve photographic clarity [17]. This included red fluorescent enamel paint, zero-size painting brushes for precise application, fevicol adhesive to ensure the paint adhered to the vessel walls, and glycerine to provide a shiny, reflective finish that improved contrast in photographs. Cotton swabs and electric fans were used to manage excess fluid and to accelerate the drying process of the paint. The methodological approach involved a systematic dissection of the upper abdominal region following standard anatomical procedures [2, 18]. Following the routine educational dissection of the peritoneal cavity by students, the region was carefully prepared for detailed examination. The stomach was reflected superiorly to expose the lesser sac and the anterior surface of the pancreas. The celiac trunk was identified at its origin from the abdominal aorta, and the dense autonomic nerve plexus surrounding it was meticulously cleared to expose the root of the splenic artery. The artery was then traced distally along its entire course, noting its relationship to the superior border of the pancreas—categorized as suprapancreatic, retropancreatic, or a combination thereof [11, 19]. All its major branches, including the short gastric, pancreatic, left gastroepiploic, posterior gastric, and any polar arteries, were identified and their origins documented [12, 20]. Finally, the terminal branching pattern at the splenic hilum was classified as either distributed or bundled, a classification system critical for surgical planning [10, 14]. Upon completion of the dissection and analysis, the entire vascular tree—including the celiac trunk, splenic artery, and all its dissected branches—was carefully painted with the red enamel mixture to provide a stark contrast against the surrounding tissue [17]. This crucial step allowed for clear visualization and accurate documentation. High-quality images of each prepared specimen were captured using a 12-megapixel digital camera to ensure fine anatomical details were preserved for subsequent analysis and record-keeping [21].

The meticulous dissection of thirty human cadavers provided a comprehensive dataset on the anatomical profile of the splenic artery. The analysis revealed significant variations in its origin, its relationship to the pancreas, its branching pattern, and the presence of polar arteries, underscoring the high degree of morphological diversity inherent in this vessel. The origin of the splenic artery was most frequently observed from the classic celiac trunk. However, in a notable minority of cases, it arose from variant arterial trunks, demonstrating that surgeons and radiologists must be prepared for atypical origins during procedures involving the upper abdominal vasculature [Figure 1 &Table 1]. Table 1: Origin of the Splenic Artery (n=30) Origin Number of Cases Percentage (%) Celiac Trunk 27 90.0% Hepatosplenic Trunk 2 6.7% Gastrolienal Trunk 1 3.3% The course of the splenic artery in relation to the pancreas was categorized based on its predominant position. A suprapancreatic course, where the artery runs along the superior border of the pancreas, was the most common trajectory. Other patterns, including segments where the artery passed behind the gland, were also documented, which has implications for surgical accessibility and the risk of iatrogenic injury during pancreatic or splenic surgery[Figure 2&Table 2]. Table 2: Course of the Splenic Artery in Relation to the Pancreas (n=30) Course Number of Cases Percentage (%) Entirely Suprapancreatic 20 66.7% Entirely Retropancreatic 2 6.7% Mixed (Supra- and Retropancreatic) 8 26.6% The branching pattern of the splenic artery was consistent in the presence of certain vessels but variable in their number. Short gastric arteries and pancreatic branches were identified in all 30(100%)specimens, arising predominantly from the main trunk of the splenic artery. The number of these branches varied from cadaver to cadaver. The left gastroepiploic artery was another constant branch, though its origin was more variable, arising from the main trunk, a terminal branch, or in one case, from an inferior polar artery. The posterior gastric artery, an inconstant branch, was identified in 6(20%) specimens [Figure 3&Table 3]. Table 3: Branching Pattern of the Splenic Artery (n=30) Branch Presence Number Range Most Common Origin Short Gastric Arteries 30 (100%) 2 - 4 Main Trunk Pancreatic Branches 30 (100%) 2 - 5 Main Trunk Left Gastroepiploic Artery 30 (100%) 1 Main Trunk / Terminal Branch Posterior Gastric Artery 6 (20%) 1 Mid-portion of Main Trunk The terminal branching pattern at the splenic hilum was classified into two main types. The distributed type, where the artery divides away from the hilum into long terminal branches, and the bundled type, where the division occurs close to the hilum resulting in short branches, were observed with nearly equal frequency[Figure 4 & Table 4]. Furthermore, the number of terminal branches entering the spleen showed variation, with two branches being the most common configuration. Table 4: Terminal Branching Pattern at the Splenic Hilum (n=30) Pattern Number of Cases Percentage (%) Number of Terminal Branches (Range) Distributed Type 15 50.0% 2 - 4 Bundled Type 13 43.3% 2 - 3 No Division (Single Trunk) 2 6.7% 1 Polar arteries, which supply the upper or lower pole of the spleen directly without passing through the hilum, were present in a subset of specimens. The inferior polar artery was more frequently observed than the superior polar artery. These vessels displayed variability in their origin, arising from the main splenic artery trunk, its terminal branches, or the left gastroepiploic artery [Figure 5 & Table 5]. Table 5: Incidence and Origin of Polar Arteries Artery Number of Cases (%) Origin (Number of Cases) Superior Polar Artery 4 (13.3%) Main Trunk (4) Inferior Polar Artery 6 (20.0%) Main Trunk (3), Terminal Branch (1), Left Gastroepiploic (2) Both Arteries Present 2 (6.7%) Both from Main Trunk (2)

The findings of this cadaveric study illuminate the complex and variable anatomy of the splenic artery, providing crucial data that aligns with, and in some aspects diverges from, existing anatomical literature. These observations have direct and significant implications for the safety and efficacy of surgical and radiological interventions in the upper abdomen. The origin of the splenic artery from the classic celiac trunk in 90% of our specimens is consistent with the findings of several major studies. Mikhail et al. [12], Von Damme and Bonte [14], and Daisy Sahni et al. [22] all reported a 100% incidence of this standard origin in their respective studies. However, our observation of variant origins—specifically from a hepatosplenic trunk (6.7%) and a gastrolienal trunk (3.3%)—corroborates the work of other researchers who have documented such anomalies. For instance, Shoumara et al. [17] reported a gastrolienal trunk incidence of 2.17%, and Chen et al. [23] found a common hepatosplenic trunk in 4.4% of their large sample, both figures being remarkably close to our findings. This reinforces the concept that while the standard anatomy is prevalent, a surgeon must always be prepared for anatomical variations that could alter the surgical approach, particularly during laparoscopic procedures where the field of view is restricted. The course of the splenic artery in relation to the pancreas is a critical factor for surgical planning. Our finding that an entirely suprapancreatic course was most common (66.7%) is supported by Pandey et al. [24], who reported a similar incidence of 74.1%. However, the presence of a retropancreatic or mixed course in over 33% of our cadavers is a key finding. As emphasized by Xu et al. [25], an artery located behind or within the pancreatic substance is notoriously difficult to isolate and ligate without mobilizing the pancreas first, increasing the complexity and risk of procedures like distal pancreatectomy or splenic vessel ligation. This high incidence underscores the value of preoperative imaging to map the artery's course. The branching pattern observed in our study showed universal presence of short gastric and pancreatic branches, which is a consistent finding across anatomical texts [2]. The number of these branches was variable, which agrees with the descriptions by Dawson et al. [15]. A notable finding was the relatively low incidence of the posterior gastric artery (20%) compared to the wide range (4% to 99%) reported in the literature reviewed by Loukas et al. [26], and the 62.3% found by Suzuki et al. [11]. This discrepancy may reflect true population-specific anatomical differences or variations in the definition used to identify this vessel. Clinically, this artery can be a critical source of collateral circulation and if missed during gastrectomy, can lead to gastric ischemia or bleeding [11]. Perhaps the most surgically relevant finding pertains to the terminal branching pattern. The nearly equal distribution between the distributed (50%) and bundled (43.3%) types has direct consequences for laparoscopic splenectomy. Our results strongly support the methodology proposed by Xu et al. [25], which recommends that in a distributed pattern, vessels must be ligated individually away from the hilum to avoid bleeding from unattended branches. In contrast, the bundled pattern allows for safer en masse ligation closer to the spleen. The prevalence of the distributed pattern in our study highlights why a "one-size-fits-all" technique is risky and why preoperative imaging with Color Doppler to determine this pattern [26] is so beneficial for planning the surgical strategy. Finally, the incidence and origin of polar arteries in our study were generally lower than those reported by Michels [10] and Katritsis et al. [13] but align more closely with some contemporary findings. These arteries are of paramount importance as they can be easily avulsed during mobilization of the splenic poles if not identified, leading to significant hemorrhage that is challenging to control laparoscopically. Their variable origin, including from the left gastroepiploic artery, means that careful dissection around all structures near the splenic hilum is mandatory.

In conclusion, the results of this study confirm that the anatomy of the splenic artery is highly variable. While our findings often align with previous work, the specific rates of variation—such as a higher incidence of non-suprapancreatic courses and a lower incidence of the posterior gastric artery—provide a unique and valuable population-specific dataset. These results reinforce the axiom that detailed knowledge of anatomy is the best way to avoid surgical mishap. Preoperative imaging, particularly Color Doppler flow imaging [26], should be leveraged to create a patient-specific "roadmap," enabling surgeons and interventional radiologists to tailor their approach, minimize operative time, and most importantly, enhance patient safety.

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