A new option for splenic preservation in normal sized spleen based on preserved histology and phagocytic function of the upper pole using upper short gastric vessels

Partial splenic embolization with embosphere microspheres (700-900 µm) for the treatment of hypersplenism: comparison of selective superior splenic artery embolization and inferior splenic artery embolization

Objective: To compare clinical outcomes of superior versus inferior splenic artery embolization in partial splenic embolization (PSE) and identify predictors of major complications. Material and methods: This retrospective case-control study included 73 patients who underwent PSE between May 2005 and April 2021. They were divided into two groups: the superior and middle splenic artery embolization group (Group A, n = 37) and the inferior and middle splenic artery embolization group (Group B, n = 36). Outcome differences and major complications between the groups were assessed. Logistic regression was used to analyze potential predictors of major complications, and the optimal cutoff value for splenic embolization rates was determined using the Youden index. Results: There were no significant differences in laboratory and radiological outcomes between the two groups. Group A had a significantly lower incidence of major complications than Group B (p = 0.049), a lower Visual Analog Scale (VAS) score for pain (p = 0.036), and a shorter hospital stay (p = 0.022). Independent risk factors for major complications included inferior and middle splenic artery embolization (odds ratio [OR] = 3.672; 95% confidence interval [CI] = 1.028-13.120; p = 0.045) and a higher spleen embolization rate (OR = 1.108; 95% CI = 1.003-1.224; p = 0.044). The optimal cutoff for spleen embolization rate to predict major complications was 59.93% (sensitivity 77.8%, specificity 63.6%). Conclusion: Using 500-700 µm microspheres for PSE, targeting the middle and superior splenic artery yields similar effects to targeting the middle and inferior artery, but results in lower rates of major complications and shorter hospital stays. To effectively minimize the risk of major complications, the embolization rate should be kept below 59.93%, regardless of the target vessel.

Does the Spleen Have a Function in Digestion? Medical History, Phylogenetic and Embryological Development of the Splenogastric System

BACKGROUND

Before the spleen was discovered to be a lymphatic blood organ, it had for centuries been considered to be a digestive organ. Concepts of a regulative, secretory and resorptive function in the digestive system were based mainly on a postulated connection between the stomach and the spleen. Splenogastric vascular connections have recently been rediscovered by modern surgery.

SUMMARY

To test the hypothesis that the spleen has a digestive function, this article reviews the literature focusing on the interaction between the spleen and the stomach. We examine the historical medical view of the spleen and stomach system and the reasons why a digestive function was abandoned in the 17th and 18th centuries. We then review the rediscovery of the splenogastric system and the present-day state of knowledge (anatomical origin, variability, haemodynamics) and present it in terms of the phylogenetic and embryological development of the spleen and stomach system. Key Message: Splenogastric arteries and gastrosplenic veins form a portal system which directly connects the spleen and stomach parenchyma. Despite its mesodermal anlage, phylogenetically and embryologically the spleen is intimately interconnected with the entodermal stomach parenchyma but detaches from this in the course of development. Further study is required to establish whether the splenogastric system is merely an evolutive remnant or actually a part of a functioning spleen-stomach system as postulated in complementary and integrative medicine.

Spleen-preserving total pancreatectomy with conservation of the spleen vessels:: operative technique and possible indications

Conventional distal pancreatectomy (cDP) and total pancreatectomy (cTP) also involve removal of the spleen. The spleen, however, is an important organ in the immunologic defense of the host and is worthy of preservation if this can be safely achieved. We performed a spleen-preserving total pancreatectomy (SPTP), with good results, in a Caucasian woman, 66-year-old, affected by pancreatic metastases of renal clear cell carcinoma. This is the first report of a SPTP for pancreatic metastases to our knowledge, and we therefore wish to describe the surgical technique and to suggest the possible indications for this new technique.

Course of the short gastric veins and their suitability for pancreatic islet transplantation

Experience is being gained with pancreatectomy for patients with chronic pancreatitis suffering intractable pain. Transplantation of pancreatic islets isolated from the patient's own pancreas reduces the amount of injected insulin required, and research aims to develop treatments to make such patients independent of administered insulin. Claims have been made that the uppermost short gastric vein runs directly to the upper pole of the spleen in about 90% of subjects and that infusion of pancreatic islets by this route would allow them to settle in the spleen. This study investigates these claims. The findings suggest that the short gastric veins are inappropriate as a route of islet administration. Most short gastric veins, including the most superior, drain to tributaries of the splenic vein. Short gastric veins passing to the spleen itself without extra-splenic connections to the splenic vein and its tributaries are relatively rare. Only four examples in 12 specimens were found, and only two of these were the most superior short gastric vein. The short gastric veins run in the fat of the gastrosplenic ligament and are most readily visible as they leave the stomach. In our 12 dissecting room specimens, the short gastric veins ranged in number from 3-17, and in diameter from 0.5-4.5 mm (mean = 1.7 mm; SD = 0.7 mm). The four short gastric veins that drained directly to the spleen ranged in diameter from 0.5-1 mm, significantly narrower than those draining to the splenic vein or its tributaries and small for cannulation.

Distribuição de Escherichia coli nos órgãos do sistema mononuclear fagocitário após esplenectomia total isolada ou combinada com auto-implante esplênico em rato

OBJETIVO: O auto-implante esplênico parece constituir a única alternativa para preservação de tecido esplênico, após esplenectomia total. O objetivo deste trabalho foi analisar a depuração de Escherichia coli pelos órgãos do sistema mononuclear fagocitário (SMF) após esplenectomia total e auto-implante esplênico. MÉTODO: Utilizou-se um modelo experimental com ratos Wistar jovens e adultos, de ambos os sexos, submetidos a esplenectomia total e auto-implante esplênico. O método de avaliação foi a inoculação intravenosa de suspensão de Escherichia coli marcada com tecnécio - 99m. Analisou-se a captação desta bactéria pelos órgãos do SMF e o remanescente bacteriano na corrente sangüínea. RESULTADOS: Dentro de cada grupo, não foi encontrado diferença entre animais jovens e adultos no que se refere à captação de bactérias pelos órgãos do SMF. Na comparação entre os grupos verificou-se que o percentual médio de captação pelo baço e pelo fígado de animais do Grupo-Controle foi maior que o dos auto-implantes. Embora a captação de bactérias pelo baço de animais do Grupo-Controle tenha sido maior que o dos auto-implantes esplênicos, o remanescente bacteriano no sangue não foi diferente. Animais submetidos a esplenectomia total isolada apresentam maior remanescente de bactérias na corrente sangüínea que animais do Grupo-Controle ou do grupo submetido a esplenectomia total combinada com auto-implante esplênico. CONCLUSÃO: Nossos resultados indicam que o auto-implante esplênico é eficaz na depuração de bactérias, em rato, mediante a fagocitose por seus macrófagos, e não interfere na função de remoção bacteriana do fígado e do pulmão.

Evaluation of phagocytic function of macrophages in rats after partial splenectomy

BACKGROUND

Understanding the immunologic properties of the spleen has enabled surgeons to practice splenic conservation surgery. If the upper pole of the spleen can be preserved solely on the upper short gastric vessels, will phagocytic function of macrophages in remnant splenic tissue be affected? The aim of this experimental study was to evaluate the phagocytic function of macrophages in partially resected spleens, with hilar excision preserving the short gastric vessels.

STUDY DESIGN

Forty-eight female Wistar albino rats were divided into four groups. Groups 1 and 2 underwent sham operations and groups 3 and 4 underwent partial splenectomy. One milliliter of sodium chloride 0.9% was injected into the abdomen of the rats in groups 1 and 3 and 1 mL of Streptococcus pneumoniae type III as an antigenic stimulus was injected into the abdomen of the rats in groups 2 and 4, 6 weeks after the first operation. Forty-eight hours later, relaparotomy was performed in all animals. India ink was used to determine the capacity of uptake in the splenic phagocytes. To evaluate the phagocytic function of the splenic tissues, histologic examinations were performed according to a macrophage grading system.

RESULTS

All spleens in all four groups were stained black after injection of India ink. Phagocytic activity of macrophages was reduced in the partially splenectomized groups, compared with intact spleen groups (group 3 versus group 1; p < 0.0001, group 4 versus group 2; p < 0.0001). There was a significant difference between groups 1 and 2 according to phagocytic function of macrophages (p = 0.0121). Also, after Streptococcus pneumoniae type III injection as an antigenic stimulus in group 4, we found that the phagocytic functions of macrophages increased compared with those of the sodium chloride 0.9%-injected group 3 after partial splenectomy (p < 0.0001).

CONCLUSIONS

Phagocytic function of macrophages in rats decreased after partial splenectomy. Nevertheless, the remnant spleens in rats could be stimulated when challenged with an antigenic stimulus.

Perfusion and functional anatomy of the splenic remnant supplied by short gastric vessels

BACKGROUND

Surgeons have described many methods to preserve the injured spleen for the maintenance of host defence. The volume and the perfusion of remaining splenic tissue are important for better functional results. Imaging the functioning tissue with radionuclide provides information about the physiology of the concerning organ.

METHODS

Thirty rats were separated into three groups: control, explorative laparotomy alone; partial splenectomy, upper part of the spleen supplied by short gastric vessels was preserved after partial resection; and devascularized spleen, the entire spleen was preserved after ligation of splenic artery. The size, functional anatomy, and perfusion status of splenic tissue were assessed by liver-spleen scintigraphy using radiolabeled heat denatured red blood cells.

RESULTS

In the partial splenectomy group, splenic radioactivity count, spleen/liver ratio, and radionuclide uptake were mildly reduced, and found to be 87% (P = 0.012), 91% (P = 0.16), and 88% (P <0.001) of the normal spleen, respectively. The area of functional tissue in the upper splenic remnant was 51% (P <0.001) of the normal spleen. In the devascularized spleen group, the radioactivity count, the ratio, and the uptake were 38% (P <10(-6)), 36% (P <10(-6)), and 49% (P <10(-6)) of the normal spleen respectively. The area of functional tissue in the devascularized spleen was calculated as 47% (P <10(-6)) of the normal spleen.

CONCLUSIONS

The collateral circulation is insufficient for proper function of the entire spleen after disconnection of the main arterial blood supply. The functional tissue is markedly impaired. On the other hand, the upper part of the spleen is remained well perfused via the short gastric vessels. The collateral circulation is satisfactory for this splenic tissue after reduction of its volume. That size splenic tissue seems to have satisfactory functional ability. Proper functional results mostly depend on the balance between the volume and blood supply of the remaining splenic tissue.

Laparoscopic floppy Nissen fundoplication

Good results for antireflux surgery are obtained when proper patients are selected, trained surgeons perform the operation, and proper techniques are used. As our prior results showed higher rates of dysphagia without fundus mobilization (Nissen-Rossetti fundoplication), we now perform complete mobilization on all patients. Full fundus mobilization requires take-down of the short gastric vessels to reveal the base of the left crus, take-down of all posterior gastropancreatic adhesions and the peritoneal fold that is cauded to the crus and superior to the pancreas. Proper division of these attachments will allow an untethered fundoplication and may reduce the risk of dysphagia and slip of the fundoplication onto the stomach.