ANATOMICAL VARIATIONS OF PORTAL VENOUS SYSTEM: IMPORTANCE IN SURGICAL CLINIC.

AIM: Knowledge of the portal system and its anatomical variations aids to prevent surgical adverse events. The portal vein is usually made by the confluence of the superior mesenteric and splenic veins, together with their main tributaries, the inferior mesenteric, left gastric, and pancreaticoduodenal veins; however, anatomical variations are frequent. This article presents a literature review regarding previously described anatomical variations of the portal venous system and their frequency. METHODS: A systematic review of primary studies was performed in the databases PubMed, SciELO, BIREME, LILACS, Embase, ScienceDirect, and Scopus. Databases were searched for the following key terms: Anatomy, Portal vein, Mesenteric vein, Formation, Variation, Variant anatomic, Splenomesenteric vein, Splenic vein tributaries, and Confluence. RESULTS: We identified 12 variants of the portal venous bed, representing different unions of the splenic vein, superior mesenteric vein, and inferior mesenteric vein. Thomson classification of the end of 19th century refers to the three most frequent variants, with type I as predominant (M=47%), followed by type III (M=27.8%) and type II (M=18.6%). CONCLUSION: Thomson classification of variants is the most well-known, accounting for over 90% of portal venous variant found in clinical practice, inasmuch as the sum of the three junctions are found in over 93% of the patients. Even though rarer and accounting for less than 7% of variants, the other nine reported variations will occasionally be found during many abdominal operations.

Three-dimensional computed tomography analysis of the vascular anatomy of the splenic hilum for gastric cancer surgery.

PURPOSE: Splenic infarction may occur if the splenic branches are injured or ligated accidentally during gastrectomy. We used three-dimensional computed tomography (3D-CT) imaging to distinguish the vascular anatomy of the splenic hilum in individual patients, focusing on the splenic polar branches and the gastric branches. METHODS: The subjects of this study were 104 patients who underwent computed tomography (CT) with intravenous contrast before gastrectomy. SYNAPSE 3D® (Fujifilm Medical, Tokyo, Japan) was used to generate the 3D-CT images. The total spleen volume and the area supplied by the superior polar artery (SPA) in each patient were estimated using the "liver analysis" function. RESULTS: The SPA without the gastric branch (supplying only the spleen), the SPA with the gastric branch (supplying both the stomach and the spleen), and the posterior gastric artery (supplying only the stomach) were present in 14, 45, and 18% of the patients, respectively. The SPA supplied 12% of the total spleen volume on average; however, it supplied over 30% in two patients. CONCLUSION: We identified the vascular anatomy around the splenic hilum in over 100 patients. Based on our findings, we recommend preservation of the SPA when it is supplying a large area of the spleen. Preoperative 3D-CT analysis provides useful information to optimize safe gastrectomy.

The anatomical configuration of the splenic artery influences suprapancreatic lymph node dissection in laparoscopic gastrectomy: analysis using a 3D volume rendering program.

BACKGROUND: The aim of this study is to categorize splenic artery and vein configurations, and examine their influence on suprapancreatic lymph node (LN) dissection in laparoscopic gastrectomy. METHODS: Digital Imaging and Communications in Medicine images from 169 advanced cancer patients who underwent laparoscopic gastrectomy with D2 dissection were used to reconstruct perigastric vessels in 3D using a volume rendering program (VP Planning®). Splenic artery and vein configuration were classified depending on the relative position of their lowest part in regard to the pancreas. Number of resected LNs and surgical outcomes were analyzed. RESULTS: The splenic artery was categorized as superficial (36.7%), middle (49.1%), and concealed (14.2%), and the splenic vein was categorized as superior (6.5%), middle (42.0%), and inferior to the pancreas (51.5%). The number of resected LNs around the proximal half of the splenic artery (#11p) and the proportion of the splenic vein located inferiorly to the pancreas were significantly higher in splenic arteries of concealed types. LN metastasis of station #7 was an independent risk factor of LN metastasis in station #11p (p = 0.010). Concealed types showed a tendency towards longer operating times, more blood loss, longer hospital stays, and a higher postoperative morbidity. CONCLUSION: Concealed types of splenic artery are associated with an increased difficulty in the dissection of LN station #11p around the splenic artery. A 3D volume rendering program is a useful tool to rapidly and intuitively identify individual anatomical variations, to plan a tailored surgical strategy, and to predict potential challenges.

Surgical Anatomy of the Superior Mesenteric Vessels Related to Pancreaticoduodenectomy: a Systematic Review and Meta-Analysis.

BACKGROUND AND PURPOSE: Mesopancreas dissection with central vascular ligation and the superior mesenteric artery (SMA)-first approach represent the cornerstone of current principles for radical resection for pancreatic head cancer. The surgeon dissecting around the SMV and SMA should be aware regarding the anatomical variants in this area. The aims of this systematic review and meta-analysis are to detail the surgical anatomy of the superior mesenteric vessels and to propose a standardized terminology with impact in pancreatic cancer surgery. METHODS: We conducted a systematic search to identify all published studies in PubMed/MEDLINE and Google Scholar databases from their inception up to March 2017. RESULTS: Seventy-eight studies, involving a total of 18,369 specimens, were included. The prevalence of the mesenteric-celiac trunk, replaced/accessory right hepatic artery (RRHA), common hepatic artery, and SMV inversion was 2.8, 13.2, 2.6, and 4.1%, respectively. The inferior pancreaticoduodenal artery has its origin into the first jejunal artery, SMA, and RRHA, in 58.7, 35.8, and 1.2% of cases, respectively. The SMV lacks a common trunk in 7.5% of cases. The first jejunal vein has a trajectory posterior to the SMA in 71.8% of cases. The left gastric vein drains into the portal vein in 58%, in splenic vein (SV) in 35.6%, and into the SV-PV confluence in 5.8% of cases. CONCLUSIONS: Complex pancreaticoduodenal resections require detailed knowledge of the superior mesenteric artery and vein, which is significantly different from the one presented in the classical textbooks of surgery. We are proposing the concept of the first jejunopancreatic vein which impacts the current oncological principles of pancreatic head cancer resection.

Splenorenal shunt via magnetic compression technique: a feasibility study in canine and cadaver.

INTRODUCTION: The concept of magnetic compression technique (MCT) has been accepted by surgeons to solve a variety of surgical problems. In this study, we attempted to explore the feasibility of a splenorenal shunt using MCT in canine and cadaver. MATERIAL AND METHODS: The diameters of the splenic vein (SV), the left renal vein (LRV), and the vertical interval between them, were measured in computer tomography (CT) images obtained from 30 patients with portal hypertension and in 20 adult cadavers. The magnetic devices used for the splenorenal shunt were then manufactured based on the anatomic parameters measured above. The observation of the anatomical structure showed there were no special structural tissues or any important organs between SV and LRV. Then the magnetic compression splenorenal shunt procedure was performed in three dogs and five cadavers. Seven days later, the necrotic tissue between the two magnets was shed and the magnets were removed with the anchor wire. RESULTS: The feasibility of splenorenal shunt via MCT was successfully shown in both canine and cadaver, thus providing a theoretical support for future clinical application.

Classification of portal vein tributaries in Thai cadavers including a new type V.

PURPOSE: To compare portal vein tributaries in Thai with Thompson classification. METHODS: In 211 Thai cadavers, abdominal regions were dissected to identify the portal veins and their tributaries. The subjects were classified into types based on modes of drainage of the left gastric and inferior mesenteric veins. Percentages of all types of venous drainage were counted. RESULTS: There are four types of portal tributaries as defined by Thompson, type I_47.87 %, type II_13.27 %, type III_7.58 %, and type IV_29.86 %. There were 1.42 % of whose inferior mesenteric veins entered the joining angle of the superior mesenteric and splenic veins, and were classified as type V. The left gastric vein mostly drained into the portal vein in 79.15 %, while the inferior mesenteric vein emptied into the splenic vein mainly in 55.45 %. CONCLUSIONS: A new variance of portal tributaries in Thai cadavers is reported. The variations of portal vein formations are critical for liver surgery and interventional radiological procedures.

Optimal management of the splenic vein at the time of venous resection for pancreatic cancer: importance of the inferior mesenteric vein.

BACKGROUND: Resection of the superior mesenteric vein (SMV)-portal vein (PV)-splenic vein (SV) confluence during pancreatectomy for pancreatic cancer requires management of the SV. DISCUSSION: Simple SV ligation can result in sinistral portal hypertension if the inferior mesenteric vein (IMV) enters the confluence and is thereby resected, or if the IMV is insufficient to drain the SV. We describe herein three patients whose clinical course confirms the importance of the IMV decompressing the SV to avoid sinistral hypertension.

[DESCRIPTION OF A RETROPERITONEAL ACCESS ROUTE TO THE VESSELS OF THE SPLEEN FOR SPLENORENAL ARTERIAL AND VENOUS ANASTOMOSIS]. / DESCRIPCIÓN DE UNA VÍA DE ACCESO RETROPERITONEAL A LOS VASOS DEL BAZO PARA LAS ANASTOMOSIS ESPLENORRENALES ARTERIALES Y VENOSAS.

To perform arterial or venous spleno-renal anastomoses, surgeons have so far systematically used the transperitoneal way whic is burdened by a high mortality an morbility percentage. On the basis of anatomo-surgical considerations, a retroperitoneal approach has been found reaching the hilus of the spleen via the lumbar region; the first arterial spleno-renal anastomosis by this way was performed in 1972 and the first venous spleno-renal anastomosis due to portal hipertension also by this way was performed in 1974, the alter proving to be the least aggresive by avoiding damaging the páncreas, the most surgical and direct for reaching the splenic vessels thereby enabling a better exposure and an easier performing of the anastomoses. By being retroperitoneal, the loss or infección of the ascitic liquid in the cirrhotic patient is prevented.

Influence of the inversion of the portal/splenic vein diameter in the results of the surgical treatment of schistossomotic portal hypertension.

OBJECTIVE: To evaluate the morbidity and mortality in surgical treatment of schistosomal portal hypertension in patients with inversion of the Portal/Splenic Vein diameter ratio. METHODS: We conducted a retrospective cross-sectional study of patients undergoing surgical treatment of portal hypertension in the period between September 1993 and January 2004. The study population was divided into two groups: a) Inversion--splenic vein diameter greater than or equal to portal vein's--and b) control group (portal vein diameter greater than the splenic vein's). Statistical comparisons used the Student t test for averages difference, chi-square test for proportions difference and Fisher's exact test for small samples. RESULTS: 169 patients were analyzed, with follow-up averaging 23.6 months. Twenty-one patients (12.4%) had splenic vein caliber greater of equal than the portal vein's (Inversion--study group). The mean preoperative diameter of the portal and splenic veins were respectively 1.49 and 1.14 cm in the control group, and 0.98 versus 1.07 cm in the inversion group. The portal vein diameter was significantly higher in the control group when compared to the inversion group (p <0.05). Varices in the gastric fundus were found in 33.3% of the inversion group and in 38.5% of patients in the control group. Postoperative rebleeding occurred in 23.1% of patients in the inversion group and in 13.4% of the control group ones (p > 0.05). In the postoperative evaluation with Doppler ultrasonography of portal vessels, no cases of portal vein thrombosis were observed in the inversion group, whilst in the control group portal thrombosis was identified in 16.9% of the patients (p <0.05). Death occurred in one (4.8%) individual from the inversion group; mortality was 4.1% in the control group (p>0.05). The mean serum level of platelets was significantly lower (65,950/mm²) in the inversion group than in the controls (106,647/mm²) (p<0.05). CONCLUSION: The results suggest that the reversal of portal/splenic vein caliber ratio does not represent a contraindication to surgical treatment of schistosomal portal hypertension.

Influência da inversão do diâmetro veia porta/veia esplênica nos resultados do tratamento cirúrgico da hipertensão portal esquistossomótica / Influence of the inversion of the portal/splenic vein diameter in the results of the surgical treatment of schistossomotic portal hypertension

OBJETIVO: Avaliar a morbidade e a mortalidade no tratamento cirúrgico da hipertensão portal esquistossomótica em pacientes portadores de inversão do diâmetro entre a veia porta e veia esplênica. MÉTODOS: Estudo transversal retrospectivo, de pacientes submetidos ao tratamento cirúrgico da hipertensão no período entre setembro de 1993 e Janeiro de 2004. A população do estudo foi distribuída em dois grupos: a) Inversão - calibre da veia esplênica maior ou igual ao da veia porta) e b) grupo controle (calibre da veia porta maior que o da veia esplênica). Na análise estatística foram utilizados o teste t de student para diferença de médias, quiquadrado para diferença de proporções e o exato de Fisher para amostras reduzidas. RESULTADOS: 169 pacientes foram analisados com seguimento pós-operatório médio de 23,6 meses. 21 pacientes (12,4 por cento) apresentavam a veia esplênica de igual ou maior calibre que a veia porta (Inversão - grupo de estudo). A média dos diâmetros pré-operatórios das veias porta e esplênica foram, respectivamente, 1,49/1,14cm no grupo controle, e 0,98/1,07cm no grupo de inversão. O diâmetro da veia porta foi significativamente maior no grupo controle quando comparado ao grupo de inversão (p<0,05). A presença de varizes de fundo gástrico foi identificada em 33,3 por cento do grupo de inversão e em 38,5 por cento dos pacientes do grupo controle. Recidiva hemorrágica pós-operatória ocorreu em 23,1 por cento dos pacientes do grupo de inversão e em 13,4 por cento no grupo controle (p>0,05). Na avaliação pós-operatória com ultrassonografia Doppler de vasos portais, não houve casos de trombose portal no grupo de inversão, e no grupo controle a trombose portal foi identificada em 16,9 por cento dos pacientes (p<0,05). O óbito ocorreu em um (4,8 por cento) paciente do grupo inversão, e a mortalidade foi de 4,1 por cento no grupo controle (p>0,05). A média do nível sérico de plaquetas foi significativamente menor (65.950/mm□) no grupo de inversão do que no grupo controle (106.647/mm□) (p<0,05). CONCLUSÃO: Os resultados sugerem que a inversão do calibre veia porta/esplênica não representa uma contraindicação ao tratamento cirúrgico da hipertensão portal esquistossomótica.

OBJECTIVE: To evaluate the morbidity and mortality in surgical treatment of schistosomal portal hypertension in patients with inversion of the Portal/Splenic Vein diameter ratio. METHODS: We conducted a retrospective cross-sectional study of patients undergoing surgical treatment of portal hypertension in the period between September 1993 and January 2004. The study population was divided into two groups: a) Inversion - splenic vein diameter greater than or equal to portal vein's - and b) control group (portal vein diameter greater than the splenic vein's). Statistical comparisons used the Student t test for averages difference, chi-square test for proportions difference and Fisher's exact test for small samples. RESULTS: 169 patients were analyzed, with follow-up averaging 23.6 months. Twenty-one patients (12.4 percent) had splenic vein caliber greater of equal than the portal vein's (Inversion - study group). The mean preoperative diameter of the portal and splenic veins were respectively 1.49 and 1.14 cm in the control group, and 0.98 versus 1.07 cm in the inversion group. The portal vein diameter was significantly higher in the control group when compared to the inversion group (p <0.05). Varices in the gastric fundus were found in 33.3 percent of the inversion group and in 38.5 percent of patients in the control group. Postoperative rebleeding occurred in 23.1 percent of patients in the inversion group and in 13.4 percent of the control group ones (p> 0.05). In the postoperative evaluation with Doppler ultrasonography of portal vessels, no cases of portal vein thrombosis were observed in the inversion group, whilst in the control group portal thrombosis was identified in 16.9 percent of the patients (p <0.05). Death occurred in one (4.8 percent) individual from the inversion group; mortality was 4.1 percent in the control group (p>0.05). The mean serum level of platelets was significantly lower (65,950/mm□) in the inversion group than in the controls (106,647/mm□) (p<0.05). CONCLUSION: The results suggest that the reversal of portal/splenic vein caliber ratio does not represent a contraindication to surgical treatment of schistosomal portal hypertension.

Evaluation of the splenic vein diameter and longitudinal size of the spleen in patients with Gamna-Gandy bodies.

PURPOSE: The aim of this retrospective study was to compare the splenic vein diameter and longitudinal size of the spleen in patients with portal hypertension in whom Gamna-Gandy bodies were present in their spleen with those of cirrhotic patients without Gamna-Gandy bodies and a control group. MATERIALS AND METHODS: Between July 2001 and February 2006, patients in whom Gamna-Gandy bodies were detected in their spleen and the number of patients who had been undergone magnetic resonance (MR) imaging with the diagnosis of chronic liver disease were determined. A total of 43 cases with Gamna-Gandy bodies were noted. Out of these patients, a case of lymphoma was excluded from the study. Additional 3 cases with splenic vein thrombosis were not included in statistical analysis. Accordingly, the splenic vein diameter and longitudinal size of the spleen in 39 patients (group 1: 12 women, 27 men; mean age, 38.5 years) with portal hypertension in whom Gamna-Gandy bodies were detected in their spleen on T1-weighted gradient-echo MR images between July 2001 and February 2006 were measured. The values obtained were compared with those of 29 cirrhotic patients without Gamna-Gandy bodies (group 2: 14 women, 15 men, mean age 48.2 years) and control group (group 3: 13 women, 18 men, mean age 46.8 years). The differences between the groups were analyzed with ANOVA and student-t test. RESULTS: Gamna-Gandy bodies were detected in 6.3% (42/670) of patients with chronic liver disease. The mean longitudinal axis of the spleen (20.2+/-4.2 cm) in group 1 was significantly greater (p<0.001) than in group 2 (14.4+/-3.9 cm). The mean splenic vein diameter was significantly larger in group 1 (14.3+/-4.0 mm) than those in groups 2 and 3 (11.2+/-3.2 mm and 7.8+/-1.4 mm, respectively). CONCLUSION: The splenic vein diameter and longitudinal size of the spleen in portal hypertensive patients with Gamna- Gandy bodies are significantly larger than that of cirrhotic patients without Gamna-Gandy bodies and that of control group.

Laparoscopic surgery combined with preservation of the spleen for distal pancreatic tumors.

BACKGROUND: Laparoscopic distal pancreatectomy combined with spleen salvage by preservation of the splenic vessels has been described in selected patients with islet cell tumors. METHODS: Laparoscopic resection of the left side of the pancreas with spleen preservation on the vasa brevia was attempted in six consecutive patients. RESULTS: Four distal pancreatectomies with spleen preservation were completed laparoscopically. There were two conversions to laparotomy. The median operating time was 300 min (range, 240-360). There was no mortality, but two patients developed a pancreatic fistula. The median postoperative hospital stay was 34.5 days (range, 5-60). All the patients remain well at a median follow-up of 30 months (range, 22-41). CONCLUSIONS: Minimally invasive surgery for distal pancreatic tumors is feasible and appropriate for most benign tumors. The spleen can be safely preserved laparoscopically on its blood supply from the short gastric vessels. The operative technique and especially the closure of the pancreatic stump need further study.

Anatomic variants of mesenteric veins: depiction with helical CT venography.

OBJECTIVE: The purpose of this study was to describe the variable anatomy of mesenteric veins on axial CT images and on volume-rendered CT venograms that use maximum intensity projection and shaded-surface display. SUBJECTS AND METHODS: Fifty-seven patients undergoing helical CT of the pancreas were included in the study. The mesenteric venous system was analyzed in 54 patients. Three patients were excluded because the helical CT data were unsatisfactory. RESULTS: On helical CT with maximum intensity projection and shaded-surface display, the superior mesenteric vein (SMV) was seen as a single trunk of variable length in 40 patients. In seven other patients, two mesenteric trunks merged separately with the splenic vein. In the remaining seven patients, the SMV was occluded by tumor. The inferior mesenteric vein drained into the splenic vein in 28 patients (56%), into the SMV in 14 patients (26%), and into the splenomesenteric angle in nine patients (18%). CONCLUSION: Both axial and volume-rendered CT venograms accurately reveal the variable mesenteric venous anatomy. CT venograms may replace conventional angiography in presurgical planning.

Laparoscopic distal resection of the pancreas with the preservation of the spleen.

UNLABELLED: Management of the pancreatic diseases is still a challenge to the laparoscopic technique. Some experience has been gained in the laparoscopic exploration of the pancreas and staging in cancer. Anatomically the accessibility of the distal pancreas provides the laparoscopic approach technically feasible. PATIENT AND METHOD: A case of insuloma in the tail of the pancreas is presented, where distal pancreatic resection was performed laparoscopically with the preservation of the spleen. In a 55 years old female patient with typical clinical symptoms of hyperinsulinism CT identified a 3 cm large solid tumor in the tail of the pancreas. Complete mobilization of the distal pancreas was enhanced by the use of an ultrasonic dissector (UltraCision). The pancreas is detached from the splenic hilum after dividing the spleen vessels. The pancreas is transected proximally by laparoscopic linear stapler. Preservation of the short gastric vessels provides the necessary blood supply of the spleen following division of the splenic artery and vein. Thus removal of the spleen is not a necessary step in this procedure. The operation was carried out within 4.5 hours. Postoperative course was uneventful, the patient left the hospital on the 5th postoperative day. Advantages of the procedure were the earlier mobilization and shorter recovery time, less postoperative pain. The procedure can be safely performed with a good experience in both pancreatic and laparoscopic surgery.

Balloon dissection in extended retroperitoneoscopy.

The anatomy of the retroperitoneum, including the high retroperitoneum, was studied as it appears with balloon dissecting techniques. We used fresh cadavers in this study. A relatively unknown fascia that is located between the lateral aspect of the perirenal fascia and the posterior parietal peritoneum, called the paraconal fascia, was a constant finding. This structure is important because it protects delicate retroperitoneal organs: the duodenum, pancreas, celiac axis, and superior mesenteric artery. Locating this fascia is an important step in the dissection of the high retroperitoneum, which is of interest in advanced videoendoscopic procedures involving retroperitoneal organs.

MR angiography of the portal and hepatic venous systems: preliminary experience with echoplanar imaging.

OBJECTIVE: The purpose of this study was to evaluate the ability of echoplanar MR angiography to depict the major hepatic and portal venous structures. SUBJECTS AND METHODS: Echoplanar and conventional MR angiographic examinations were performed in 10 subjects (seven healthy volunteers, three patients with focal hepatic lesions). A gradient-recalled echo (GRE) time-of-flight technique (125/10 [TR/TE], 90 degrees flip angle) was used for echoplanar angiography. Eight complete single-excitation images were acquired at each level in 1.5 sec and then collapsed into a single maximal intensity projection. Conventional time-of-flight MR angiography (34/13, 30 degrees flip angle) also was performed. The vascular anatomy from the right atrium to the splenic vein was imaged (6-mm contiguous levels) in three 10.5-sec breath-holds with echoplanar imaging, as compared with seven 11.5-sec breath-holds with conventional MR angiography. Echoplanar and conventional images were compared quantitatively and qualitatively. RESULTS: Echoplanar imaging was 61% faster than conventional MR angiography. Vessel-to-liver signal-intensity ratios were significantly higher for echoplanar imaging (p < .0001), signal-to-noise ratios were significantly higher for conventional MR angiography (p < .0001), and contrast-to-noise ratios were comparable. Qualitatively, echoplanar imaging and conventional MR angiography provided similar anatomic information about the hepatic and portal veins. CONCLUSION: Angiograms of the hepatic and portal venous systems that are of diagnostic quality can be acquired much more quickly with echoplanar imaging than with conventional MR angiography.

Estudo anatômico da drenagem venosa do baço humano e sua segmentaçäo / Anatomic study of the venous drainage of human spleen and its segmentation

Apesar da anatomia arterial do baço ter sido bem estudada, o mesmo näo ocorre com a anatomia venosa. Nosso objetivo foi trazer mais subsídios anatômicos a cirurgia conservadora do baço. Quarenta moldes vinílicos obtidos da árvores venosa de baços humanos foram analizados, enfocando-se as raízes formadoras da veia explênica, a segmentaçäo venosa do órgäo, a drenagem venosa de cada segmento, sua disposiçäo em relaçäo ao maior eixo lineal, bem como a presença de anastomosis. Concluímos que o baço é dotado de segmentos venosos, cujo número varia de 2 a 5, drenados por raízes, radiculas ou ambas, e na maioria das vezes sobrepostos segundo o maior eixo explênico. A veia lienal pode ser formada por 2 ou 3 raízes e a presença de anastomoses venosas foi constatada em um número maior de casos do que demonstra a literatura

Surgical anatomy of the human spleen.

Post-splenectomy sequelae are now well recognized, and conservative splenic surgery is widely advocated. However, controversies exist regarding splenic surgical anatomy. We studied 127 human spleens using anatomical dissection and a sequential injection method involving both radiology and corrosion casting, with the primary aim of examining segmental splenic anatomy and blood supply. The existence of well-defined splenic segments was confirmed and these ranged in number from 3 to 7 with a mean of 4.3. Each segment had its own arterial supply and venous drainage. The segments were separated from each other by avascular planes. Subsegments with independent blood supply were also identified. The splenic artery was found to divide into two branches; in all cases these further divided into segmental arteries supplying the central segments of the spleen. The polar segments were supplied by segmental vessels of highly variable origin and size. This study aims to highlight the importance of identifying these segmental vessels at operation when splenic conservation is considered.