Optimal site and amount of splenic tissue for autotransplantation

Spleen: Reparative Regeneration and Influence on Liver

This review considers experimental findings on splenic repair, obtained in two types of small animal (mouse, rat, and rabbit) models: splenic resections and autologous transplantations of splenic tissue. Resection experiments indicate that the spleen is able to regenerate, though not necessarily to the initial volume. The recovery lasts one month and preserves the architecture, albeit with an increase in the relative volume of lymphoid follicles. The renovated tissues, however, exhibit skewed functional profiles; notably, the decreased production of antibodies and the low cytotoxic activity of T cells, consistent with the decline of T-dependent zones and prolonged reduction in T cell numbers. Species-specific differences are evident as well, with the post-repair organ mass deficiency most pronounced in rabbit models. Autotransplantations of splenic material are of particular clinical interest, as the procedure can possibly mitigate the development of post-splenectomy syndrome. Under these conditions, regeneration lasts 1-2 months, depending on the species. The transplants effectively destroy senescent erythrocytes, assist in microbial clearance, and produce antibodies, thus averting sepsis and bacterial pneumonia. Meanwhile, cellular sources of splenic recovery in such models remain obscure, as well as the time required for T and B cell number reconstitution.

Splenic auto-transplantation after splenectomy for trauma: evaluation of a new technique

BACKGROUND

Splenic autotransplantation is a promising method to recover splenic functions after traumatic splenectomy. However, it is associated with several postoperative complications, such as subphrenic abscess, intestinal obstruction and torsion of the omentum with necrosis of the implanted splenic tissues. Therefore, the aim of this study is to evaluate a new splenic autotransplantation technique that could overcome those complications.

MATERIALS AND METHODS

A single segment of the spleen was implanted inside a pedunculated omental pouch and fixed in the native site of the spleen in 15 patients who underwent splenectomy for abdominal trauma. This group of patients was compared with the next 17 patients who underwent splenectomy alone. Additionally, splenic functions of the patient and control groups were evaluated 3 months using peripheral blood smear [the presence of Howell-Jolly (HJ) bodies] and abdominal contrast-enhanced computed tomography (CECT).

RESULTS

All patients who underwent splenic autotransplantation showed evidence of a well-vascularised splenic tissue on CECT and normal peripheral blood smear without HJ bodies 3 months postoperatively. No postoperative complications related to splenic autotransplantation were observed, and platelet count after 3 months was significantly higher in patients who underwent splenectomy only (p = 0.04).

CONCLUSIONS

Splenic autotransplantation using the aforementioned technique could restore splenic functions with minimum postoperative complications related to the procedure.

Splenic autotransplantation: a systematic review

BACKGROUND

Splenectomy is a surgical procedure indicated in a variety of medical conditions including trauma. Post-operatively, there is a lifelong risk of developing overwhelming sepsis from encapsulated bacteria, most commonly due to Streptococcus pneumoniae. Splenic autotransplantation has been proposed as a method to recover splenic function in patients requiring splenectomy with otherwise normal spleens. This study aims to systematically review the literature to determine the efficacy of spleen autotransplantation.

METHODS

MEDLINE, PubMed and the Cochrane Library were searched for all studies assessing splenic autotransplantation (January 1947 to July 2018). Data were extracted on study characteristics, outcomes assessed, including spleen scintigraphy results, blood film counts and serum immunoglobulin (Ig) levels.

RESULTS

Data were obtained from 18 primary studies. All studies demonstrated return of regenerated spleen tissue in the majority of their patients (95.3%) on spleen scintigraphy. In 12 studies, 90.2% of patients had blood films return to normal following transplantation. Ig levels were shown to return to normal in all 12 studies where it was assessed. In 11 studies, 3.7% of patients had post-operative complications. In five studies, 1.3% of patients had post-operative infections in the follow-up period.

CONCLUSION

Splenic autotransplantation is a safe procedure with minimal complications that can return splenic filtration function and Ig levels to normal ranges. It has not been confirmed whether autotransplantation provides meaningful protection against overwhelming post-splenectomy infections.

Sonographic Discovery of Autotransplanted Splenic Implants in a Pregnant Patient

It is important to include splenic implants in the differential diagnosis of patients with a history of splenic trauma. Autotransplanted splenic implants may have a sonographic appearance similar to that of pathologies such as lymphadenopathy or carcinomatosis.

This is the first known case to discuss a pregnant patient with a history of autologous autotransplanted splenic tissue, which was discovered on sonography and confirmed during the patient’s cesearean section.

Splenic implant preservation after conservation in lactated Ringer´s solution

OBJECTIVE

to evaluate the morphology and function of autogenous splenic tissue implanted in the greater omentum, 24 hours after storage in Ringer-lactate solution.

METHODS

we divided 35 male rats into seven groups (n=5): Group 1: no splenectomy; Group 2: total splenectomy without implant; Group 3: total splenectomy and immediate autogenous implant; Group 4: total splenectomy, preservation of the spleen in Ringer-lactate at room temperature, then sliced ​​and implanted; Group 5: total splenectomy, ​​spleen sliced and preserved in Ringer-lactate at room temperature before implantation; Group 6: total splenectomy with preservation of the spleen in Ringer-lactate at 4°C and then sliced ​​and implanted; Group 7: total splenectomy and the spleen sliced for preservation in Ringer-lactate at 4°C before implantation. After 90 days, we performed scintigraphic studies with Tc99m-colloidal tin (liver, lung, spleen or implant and clot), haematological exams (erythrogram, leucometry, platelets), biochemical dosages (protein electrophoresis) and anatomopathological studies.

RESULTS

regeneration of autogenous splenic implants occurred in the animals of the groups with preservation of the spleen at 4ºC. The uptake of colloidal tin was higher in groups 1, 3, 6 and 7 compared with the others. There was no difference in hematimetric values ​​in the seven groups. Protein electrophoresis showed a decrease in the gamma fraction in the group of splenectomized animals in relation to the operated groups.

CONCLUSION

the splenic tissue preserved in Ringer-lactate solution at 4ºC maintains its morphological structure and allows functional recovery after being implanted on the greater omentum.

Effects of splenic allograft in lipid profile of non-splenectomized rats: the immune and metabolic role of the "double spleen"

OBJECTIVE

To elucidate the role of the spleen and splenic allograft in lipid control and evaluate its effect on the lipid profile of rats.

METHOD

32 male Wistar rats were randomly assigned into four groups: control group (1), total splenectomy group (2), splenectomy and implantation of allograft group (3) and double spleen group (4). Each group was subdivided into two subgroups: A and B, based on the death of the animals after 30 or 120 days of monitoring. The procedures in groups 2, 3 and 4 were made simultaneously, and splenectomized animals, groups 2 and 3 were donors, respectively, for the animals of groups 3 and 4. In group 4 the spleen was preserved and the animals received implants from the spleens of rats from group 3. The regeneration of splenic tissue was evaluated by macroscopic and microscopic analyzes of the grafts and own spleens, as well as with measurements of VLDL, HDL, LDL, total cholesterol and triglycerides.

RESULTS

after 120 days, Group 4 showed levels of total cholesterol and LDL lower than the other groups. Group 1 had higher levels of lipids.

CONCLUSION

The technique of double spleen was effective in the control of lipid metabolism, corroborating the function of the spleen as a reserve of lipids.

A solution to the negative effects of splenectomy during colorectal trauma and surgery: an experimental study on splenic autotransplantation to the groin area

BACKGROUND

Splenectomy after combined colosplenic trauma or iatrogenic splenic injury during colorectal surgery associates with worse short- and long-term outcomes, including reduced survival in patients with colorectal cancer. Splenic autotransplantation may improve the outcomes of such patients. Omental splenic transplantation is the standard procedure but may be difficult when performing laparoscopic colorectal surgery or when total or subtotal omentectomy is required. This animal model study was performed to evaluate the impact of splenic autotransplantation to the groin area on colonic wound healing.

METHODS

Thirty rats were divided into three groups of ten animals. One group underwent colon anastomosis and sham splenectomy, the second underwent colon anastomosis and splenectomy, and the third underwent colon anastomosis, splenectomy, and intramuscular autotransplantation of the spleen. On postoperative day 7, anastomotic healing was evaluated by measuring bursting pressure and hydroxyproline levels. The third group was subjected to scintigraphy before sacrifice to assess whether the transplant was functional.

RESULTS

The mortality rates of the sham, splenectomized, and transplanted animals were 0 %, 30 %, and 20 %, respectively: the splenectomized animals had significantly lower mean bursting pressures than the other two groups (p = 0.002). The mean hydroxyproline levels of the three groups were 467.4, 335.3, and 412.7 mg hydroxyproline/g protein, respectively (p = 0.0856). Nine of the ten transplanted animals (90 %) had splenic activity on scintigraphy.

CONCLUSIONS

Splenectomy impaired the healing of the colonic anastomosis. This effect was largely reversed by splenic autotransplantation. Intramuscular autotransplantation to the groin area appears to be feasible and effective.

Spleen function after preservation in a physiological solution

BACKGROUND

The purpose of this study was to evaluate the morphology and function of implanted autogenous spleen tissue after 24 h of preservation in a physiological solution.

MATERIAL AND METHODS

Thirty-five male rats were divided into seven groups (n = 5): group 1, without surgical procedure; group 2, total splenectomy; group 3, total splenectomy and immediate implant of autogenous spleen tissue; group 4, total splenectomy and preservation of the entire spleen in lactated Ringer solution at room temperature for 24 h, followed by spleen sectioning and implantation; group 5, total splenectomy, followed by spleen sectioning and preservation in lactated Ringer solution at room temperature for 24 h and subsequent implantation of the slices; group 6, total splenectomy and preservation of the entire spleen in lactated Ringer solution at 4°C for 24 h, followed by spleen sectioning and implantation; and group 7, total splenectomy, the spleen was sliced and preserved in lactate Ringer solution at 4°C for 24 h, followed by implantation of the slices. After 90 d, scintigraphic studies using sulfur colloid labeled with 99mTc of the liver, lungs, spleen, implants, and a blood clot were performed. Hematological (erythrogram, leukogram, and platelets) and histologic studies were carried out.

RESULTS

The autogenous splenic implants regenerated in all animals that received those implants preserved at 4°C and immediately after excision. The scintigraphic study showed a better phagocytic function in groups 1, 3, 6, and 7. No difference was observed in the hematological study.

CONCLUSIONS

Spleen tissue preserved in lactated Ringer solution at 4°C for 24 h maintains its vitality and capacity to recover hematological and phagocytic functions.

Phagocytic function of lower spleen pole and autogenous splenic implants in rats

PURPOSE

To investigate whether there are differences between the phagocytic function of the remaining lower spleen pole after subtotal splenectomy and autogenous splenic implants.

METHODS

Thirty-six male Wistar rats, weighting 364 ± 60g were used. They were subjected to subtotal splenectomy preserving the lower spleen pole and to autogenous splenic implant in the greater omentum. Its viability was assessed microscopically. Phagocytic function was assessed by splenic uptake of the radioisotope-labeled colloid and by macrophages counting.

RESULTS

The viability of the autogenous splenic implant and of the lower spleen pole was found in 33 animals, with no difference between them. The weight of the implants was higher than the lower pole of animals from groups G1, G7, G30, G60 and G120. The implants phagocytic function by radioisotope uptake was higher than the lower pole in G7 and G120 groups and it did not differ from the other groups. The number of macrophages was higher in G1, G60, G90 and G120 and did not differ from the other groups.

CONCLUSION

Until the 16th week, the phagocytic function was more pronounced in autogenous splenic implants when compared with the lower spleen pole, but it became similar thereafter.

Single-incision laparoscopic splenectomy and splenic autotransplantation for an enlarged wandering spleen with torsion

A wandering spleen is a rare condition in which the spleen is not located in the left upper quadrant, but instead is found in the lower abdomen or in the pelvic region because of the laxity of the peritoneal attachments. The unusually long pedicle is susceptible to twisting, which can lead to ischemia, and eventually to necrosis. We herein report a case of an enlarged wandering spleen with torsion, successfully treated by single-incision laparoscopic splenectomy and autotransplantation. The transplanted splenic tissues could be identified on a spleen scintigram obtained 3 months after the surgery. Howell-Jolly bodies were not observed in blood specimens. This procedure is able to prevent an overwhelming postsplenectomy infection, and leads to satisfactory cosmetic results.

Experimental splenosis in the liver and lung spread through the vasculature

To demonstrate that intra-organ splenosis can engraft and develop after being distributed through the vasculature, tiny fragments of splenic tissues were injected into the inferior vena cava or the portal vein to induce intrapulmonary and intrahepatic splenosis in rats. After 1 month, splenic autograft structures in the lung and liver were assessed for structure by histology, for immunologic compartments by immunohistochemistry, for phagocytic function by carbon uptake and for vascular formation by Microfil (a silicon rubber compound) injection. Intrapulmonary and intrahepatic splenoses were indeed able to spread through the vasculature. The intrapulmonary splenic autografts were trapped and spread out in the interstitium, without forming a capsule. White pulp was markedly developed, showing lymphocyte aggregations that consisted in B cells surrounding the dilated vessel. Splenic sinuses were not definitively observed. Although macrophages were detected by immunohistochemistry, they showed no indication of having phagocytized carbon particles from the vessels, implying a closed circulation. In contrast, intrahepatic splenic autografts formed well-developed capsules, trabeculae and red pulp with splenic sinuses. Macrophages detected by immunohistochemistry were observed capturing carbon particles, which clearly revealed an open system circulation, as seen in normal rat spleen. The development of white pulp was poor and lymphocytes consisting in B cells aggregated in the peripheral margins. These results demonstrate that intra-organ splenosis can spread through the vasculature and that the morphologic and immunologic structures formed in these regenerated autografts are influenced by the organ vasculature and extracellular matrix wherein the tissue fragments settled.

Blood clearance of Howell-Jolly bodies in an experimental autogenic splenic implant model

BACKGROUND

Autogenic splenic implant (ASI) is one of the few alternatives for preservation of splenic tissue when total splenectomy is inevitable. The aim of this study was to determine the morphological and functional regeneration of ASIs, as indicated by the clearance of Howell-Jolly (HJ) bodies, in an experimental model.

METHODS

Ninety-nine male Wistar rats were divided into three groups: sham-operated (group 1), total splenectomy alone (group 2), and total splenectomy combined with ASI (group 3). Animals in group 3 were further allocated to nine subgroups of nine rats each, and analysed at different time points (1, 4, 8, 12, 16, 20, 24, 28 and 32 weeks after surgery). Blood smears were prepared at predetermined times for detection of HJ bodies. Morphological regeneration of tissue in the ASI was analysed by histology.

RESULTS

At 1 week, the regenerated mass corresponded to about 7 per cent of the tissue implanted, reaching approximately 54 per cent at 24 weeks. The HJ body levels were increased in groups 2 and 3 until 8 weeks after surgery, following which levels in the ASI group became similar to those in the sham-operated group. HJ bodies were difficult to detect when a level of 22.5 per cent of regenerated ASI mass was reached.

CONCLUSION

Functional regeneration of ASIs occurred from 8 weeks after surgery. When 22.5 per cent of regenerated ASI mass was reached almost no HJ bodies could be observed in the bloodstream, resembling a spleen in situ.

SURGICAL RELEVANCE

Splenectomy has been practised routinely, both in the emergency setting and as a therapeutic elective procedure. There is a correlation between asplenia/hyposplenia and the occurrence of fulminant sepsis, underlining the importance of developing surgical methods for preserving splenic function. Both clinical and experimental studies have shown at least partial morphological and functional regeneration of autogenic splenic implants (ASIs). Experimental studies investigating the immunoprotective effect of ASIs, based mostly on exposure of animals to various bacteria, have demonstrated that ASIs can increase the rate of bacterial clearance and decrease mortality from sepsis. Clinical studies have shown their ability to remove colloidal substances and altered erythrocyte corpuscular inclusions, such as Howell-Jolly, Heinz and Pappenheimer bodies, from the bloodstream. In this experimental study the functional and morphological regeneration of ASIs was studied over time in rats.

Critical mass of splenic autotransplant needed for the development of phagocytic activity in rats

When total splenectomy is inevitable, heterotopic splenic autotransplantation seems to be the only alternative to maintain the functions of the spleen. The present study was carried out to analyse the critical mass of splenic autotransplant (SAT) for the development of phagocytic activity in rats. Wistar rats were submitted to total splenectomy (TS) alone or in combination with slices of SAT ranging from an average rate of 21·9% (one slice) to 100% (five slices) of the total splenic mass implanted into the greater omentum. Sixteen weeks after the beginning of the experiment, the animals were inoculated intravenously with a suspension of Escherichia coli labelled with Tc-99m. After 20 min, the rats were killed and the liver, lung and spleen or SAT, as well as blood samples were removed to determine the percentage of labelled bacteria uptake in these tissues. As the percentage of the total splenic mass contained in the SAT increased, the bacteria remaining in the blood decreased. From the implant of 26% up to the implant of the total splenic mass (100%) there was no difference in the bacteria remaining in the blood between the healthy animals of the control group and those submitted to TS combined with SAT. This finding shows that the critical mass needed for the development of phagocytic activity of macrophages in splenic autotransplants in adult rats is 26% of the total splenic mass.

Aspectos morfológicos e funcionais dos autoimplantes esplênicos em ratos tratados com oxigenio hiperbárico

OBJETIVO: Estudar aspectos morfológicos e funcionais dos autoimplantes esplênicos de ratos submetidos ou não à oxigenioterapia hiperbárica (OHB). MÉTODOS: Foram estudados em dois períodos distintos 105 ratos Wistar. No período mediato (n= 56) os animais foram avaliados até o 11º dia de pós-operatório, e no período tardio (n= 49), até o 70º dia. Em cada período os ratos foram distribuídos nos grupos: A- Simulação, B- Autoimplante esplênico, tratados com oxigênio hiperbárico ou não. Nos animais do Grupo A realizou-se apenas manipulação do baço. Nos animais do Grupo B realizou-se esplenectomia total e a seguir quatro fragmentos do baço foram implantados no grande omento. Em todos os animais foram dosados os lípides e imunoglobulinas e contadas as plaquetas e os corpúsculos de Howell-Jolly no pré-operatório e no 11º ou 70º dia de pós-operatório. O baço dos animais do Grupo A e os autoimplantes dos animais do Grupo B foram retirados e enviados para avaliação morfológica. RESULTADOS: No grupo B11nt houve aumento do colesterol total, LDL-colesterol, VLDL-colesterol e triglicérides. No grupo B70nt houve aumento do colesterol total e LDL-colesterol. Nos grupos tratados não houve alterações lipídicas. A IgM caiu nos grupos B e não alterou nos grupos A. Os corpúsculos de Howell - Jolly foram menos freqüentes nos grupos Bt que nos grupos Bnt. As plaquetas aumentaram nos grupos B11t e B11nt e não se alteraram nos demais grupos. A viabilidade microscópica dos grupos Bt foi melhor que a dos grupos Bnt. CONCLUSÃO: Os autoimplantes esplênicos dos animais tratados com OHB apresentaram melhor função e viabilidade do que os autoimplantes dos animais não tratados.

Vanishing spleen after Nissen fundoplication: a case report

Nissen fundoplication is a generally accepted treatment for severe gastro-oesophageal reflux after conservative management has failed. The surgical techniques and the complications that may develop following the operation have been well described. However, necrosis of the spleen is a rare complication. We report here a patient with Down syndrome with a vanishing spleen after a Nissen fundoplication, who died of overwhelming pneumococcal septic shock 7 months after the operation. Vascular anomaly in Down syndrome, inadvertent ligation of the splenic artery or volvulus of the spleen may have caused a compromised splenic arterial circulation.Conclusion Nissen fundoplication may be associated with vanishing spleen and, consequently, with devastating consequences.

Esplenectomia parcial para tratar hemangioma esplênico

Apesar de a esplenectomia ser eficaz na abordagem terapêutica de pacientes com hemangioma esplênico, esse procedimento é acompanhado de elevada morbidade e até mortalidade, principalmente devido à sepse, quando realizado em crianças e adolescentes com sistema imunitário ainda imaturo. Para prevenir os efeitos adversos da asplenia, propõe-se neste artigo a esplenectomia parcial, com a retirada apenas da região do hemangioma, mantendo o restante do baço e preservando suas importantes funções.

The Prevention and Management of Infections in Children with Asplenia or Hyposplenia

Overwhelming sepsis remains a significant complication of asplenia and hyposplenia. The mainstays of prevention are education, immunization, and prophylactic antibiotics. Evidence to base recommendation and guidelines is lacking. Such decisions as the specific immunizations required, the timing of immunizations, the duration of antibiotic prophylaxis, and the prevention of overwhelming postsplenectomy sepsis in children undergoing splenectomy are often empiric. This article reviews the current literature on the prevention and management of severe infections in children with underlying asplenia or hyposplenia.

Operações laparoscópicas conservadoras do baço para tratar dor esplênica por isquemia

RACIONAL: Desde 1979 este grupo de autores executa esplenectomia conservadora através de esplenectomia sub-total e autotransplante esplênico. Estes procedimentos foram realizados em mais de 300 pacientes para tratar diferentes condições patológicas. OBJETIVO: Apresentar proposta original e inédita em seres humanos de esplenectomia subtotal, preservando apenas o pólo superior do baço por via laparoscópica e esplenectomia total complementada por implante autógeno de tecido esplênico, também pela via laparoscópica, como nova forma de tratamento da dor severa devida à isquemia do baço. MÉTODOS: Três pacientes com intensa dor no hipocôndrio esquerdo foram submetidos a grande número de exames para concluir que sua dor era provocada por isquemia de parte do baço. A dor era resistente a todos os métodos conservadores utilizados. Decidiu-se, então, pelo tratamento cirúrgico por meio da esplenectomia subtotal, preservando o pólo superior do baço suprido pelos vasos esplenogástricos em dois casos, e esplenectomia total complementada por implante no omento maior de 20 fragmentos retirados desse baço, no terceiro caso. As três operações foram realizadas por via laparoscópica. Os três doentes foram acompanhados com exames hematológicos, imunológicos, tomográficos e cintilográficos. RESULTADOS: Esses procedimentos foram conduzidos sem risco para os paciente e com sangramento mínimo. Não houve dificuldade técnica nem complicações per ou pós-operatórias. No seguimento, não foram constatadas anormalidades, comprovando-se a vitalidade e a função dos remanescentes esplênicos. A dor esplênica desapareceu desde o dia da operação e não retornou durante o período de acompanhamento. CONCLUSÃO: A esplenectomia subtotal e os auto-implantes esplênicos são factíveis por via laparoscópica, de maneira segura para os doentes e devem deve ser considerados no tratamento da dor de origem isquêmica do baço.

Laparoscopic splenic autotransplantation

Since 1990, we have performed splenic autotransplantation in more than 100 patients to treat splenic trauma, portal hypertension, myeloid metaplasia due to myelofibrosis, chronic lymphocytic leukemia, and Gaucher disease. The aim of this present study was to present splenic autotransplantation performed by laparoscopic means. A 33-year-old woman with severe splenic pain due to ischemia caused by multiple focal thromboses of splenic arterial branches was successfully treated by laparoscopic splenectomy and splenic tissue autotransplantation. The spleen was removed and cut in 20 fragments that were sutured to the greater omentum. This procedure was safely conducted with minor bleeding and no technical difficulties or complications. The postoperative follow-up of 12 months has been uneventful; the patient's pain disappeared on the first postoperative day. Hematologic, immunologic, tomographic, and scintigraphic examinations confirmed the functions of the splenic autotransplants. It is feasible and safe to perform splenic autotransplants by laparoscopic means.

Lipidic profile among rats submitted to total splenectomy isolated or combined with splenic autotransplant

PURPOSE: To evaluate the alterations on plasmatic lipids levels among rats submitted to total splenectomy isolated or combined with splenic autotransplant receiving standard chow during the postoperative period. METHODS: Thirty Wistar rats were divided into three groups: control (C) - sham-operated, total splenectomy - isolated (TS) or combined with splenic autotransplantation (SA). Since the postoperative period, all animals received standard rat chow manipulated in accordance to the American Institute of Nutrition Rodents Diets (1993). The plasmatic levels of total cholesterol (TC), triglycerides (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), very-low-density lipoprotein (VLDL), and glucose (GLUC) were analyzed before the surgical procedure and after 6 and 12 weeks. RESULTS: All the animals presented significant increase of TG and VLDL levels. In relation to the other parameters there was no difference among the weeks 0 and 12 in the animals of group C. In TS group significant increase was observed in TC and GLUC levels during the experiment. In SA group TC, HDL, and GLUC levels remained unaffected while HDL levels increased. CONCLUSION: Our findings suggest that isolated total splenectomy alters lipids metabolism in rats fed with standard chow and splenic autotransplantation is effective in restoring its control.

Preservative spleen surgery and hyperbaric oxygen therapy

PURPOSE: To assess functional and morphological aspects of spleen auto-implants and of the splenic inferior pole of rats, post-operatively treated or not with hyperbaric oxygen, as well as the survival of these animals, were studied. METHODS: Seventy-eight male Wistar rats, weighing between 192 and 283 g ( 238,3 ± 9,6g), were randomly distributed into three groups: Group1-(n=20), spleen manipulation; group 2-(n=36), spleen auto-implantation; group3-(n= 22), subtotal splenectomy preserving the inferior pole. Each group was subdivided as follows: subgroup a, not submitted to hyperbaric oxygen therapy: 1a(n=10), 2a(n=21), 3a(n= 13); subgroup b, submitted to the therapy: 1b(n=10), 2b(n=15), 3b(n=9). Blood was collected pre-operatively and 11 days after surgery, for the estimation of lipids and immunoglobulins and the counting of platelets and Howell-Jolly corpuscles. The spleen and remains were taken for histological study. RESULTS: The number of surviving animals was significantly higher in groups 1(p<0,01) and 3(p<0,05) relative to those of subgroup 2a. Total cholesterol and the LDL fraction increased significantly in subgroup 2a (p<0,01) and 3a (p<0,05), and remained unaltered in subgroups 2b e 3b. IgM decreased more significantly in subgroup 2 than in subgroup 3 (p<0,001 vs p<0,01). The increase of platelet numbers and the appearance of Howell Jolly corpuscles was smaller in subgroup 2b compared to subgroup 2a , and in group 3 compared to group aqui-> 2. The macro and microscopic appearance in subgroup 2b were more viable than in subgroup 2a, and that of group 3 more viable than in group 2. The survival of the animals carrying their whole spleen or its inferior pole was more frequent than that of the auto-implanted animals. CONCLUSION: Functionality and viability of the whole spleen or of its inferior pole, were better than in the auto-implanted animals. Hyperbaric oxygentherapy contributed to increased survival frequency of auto -implanted animals, and to improve the functionality and viability of the auto-implants and the function of the inferior splenic pole, and did not interfere in animals carrying their whole spleen.

Splenic autotransplantation for a congested and enlarged wandering spleen with torsion: report of a case

In children with diseases of the spleen, every effort should be made to preserve the organ, to prevent severe infections postsplenectomy. We report the case of a 7-year-old girl with torsion of a wandering spleen who we treated by autotransplantation of splenic tissues following splenectomy, when fixation of the enlarged spleen seemed impossible. Spleen scintigraphy showed uptake in the regenerating splenic tissues 9 months after surgery, and evidence of an increase in the size of the tissues 23 months after surgery. Howell-Jolly bodies had disappeared by 16 months after surgery. These findings suggested that the transplanted splenic tissues were resuming splenic functions. Based on our experience with this case, we conclude that autotransplantation after splenectomy is a treatment option for wandering spleen with torsion when fixation seems difficult because of splenic congestion and enlargement.

Cellular and serological changes in the peripheral blood of splenectomized and spleen autotransplanted mice

BACKGROUND

Our department worked out a modified surgical form of spleen autotransplantation earlier, named "spleen apron method" introduced already into the clinical practice. Recently we tested the immunological changes in a group of patients autotransplanted with about 10-15% of their spleen, what was the at least always implantable amount after the severe splenic injuries. In the current work we aimed at measuring some cellular and serological changes in the peripheral blood of splenectomized and spleen autotransplanted inbred mice two and eight months after the operations in order to get more unambiguous results than that we could obtain in our patients with this technique.

MATERIALS AND METHODS

We divided 96 two months old Balb/c female mice into eight groups (n = 12/group). The group of controls, sham operated, splenectomized and autotransplanted animals with two and eight months of survival time after the operations. During the autotransplantation we inserted the same amount of spleen, five slices, "chips," about 10-15% of total mass of spleen, into the greater omentum similarly as it was used in the patients. The concentration of serum proteins were measured by laser nephelometry. The lymphocyte subsets were analyzed by flow cytometry.

RESULTS

We found that two months after the operations the number of CD 19+ B-cells increased in the splenectomized but decreased in the autotransplanted animals. Eight months after the operations the number of both CD3+ T and CD19+ B lymphocytes decreased both in the splenectomized and autotransplanted animals compared to the controls and sham operated mice. However, the numbers of T and B cells were slightly but not significantly higher in the autotransplanted than in the splenectomized mice. The serum level of IgM was also decreased in the splenectomized and autotransplanted mice at both time points, however, eight months after the operations the concentration of IgM was significantly higher in the autotransplanted group than in the splenectomized animals.

CONCLUSION

The effects of autotransplanted "chips" were different at the various ages of the animals. Additionally, they showed some immunological benefit being quantitatively in accordance to the amount of the transplanted spleen. The elevated level of serum IgM what we found in the autotransplanted mice even with this amount of transplanted spleen eight months after the operations, however, might have the potentially greatest importance compared to splenectomy. These experiments can prove that the attempts for autotransplantation may have real perspectives but their efficacy depends on the amount of the successfully transplanted (saved) mass of spleen.

The prevention and treatment of bacterial infections in children with asplenia or hyposplenia: practice considerations at the Hospital for Sick Children, Toronto

Children born without a spleen or who have impaired splenic function, due to disease or splenectomy, are at significantly increased risk of life-threatening bacterial sepsis. The mainstays of prevention are education, immunization, and prophylactic antibiotics. The availability of conjugate 7-valent pneumococcal vaccines for use in children to age 9 years at least, as well as conjugate meningococcal C vaccine in some countries, for use beginning in infancy, appear to represent beneficial additions, but not substitutions, to previous recommendations for the use of polysaccharide 23-valent pneumococcal and quadrivalent A, C, Y, W-135 vaccines. Routine immunization against H. influenzae type b should continue with non-immunized children older than age 5 years receiving two doses 2 months apart, similar to children who have not previously received conjugate pneumococcal vaccine in infancy. Annual influenza immunization, which reduces the risk of secondary bacterial infection, is also recommended for asplenic children and their household contacts. Many experts continue prophylaxis indefinitely although prophylaxis of the penicillin allergic child remains suboptimal.

Distribution of peripheral blood cells in mice after splenectomy or autotransplantation

Our aim was to compare the distribution changes of peripheral leukocytes and erythrocytes in splenectomized and spleen-autotransplanted BALB/c female mice (n = 96), 2 and 8 months after surgery. In total, there were eight groups of animals: splenectomy, autotransplantation, sham, and untreated controls at both time points. We used the spleen-apron method of Furka et al. (Khirurgiia (Mosk) 1989;9:125-127), inserting five spleen chips into the greater omentum, for autotransplantation. Quantitative and qualitative blood cell counts and the phagocytic activity of cells (stimulated with zymosan) were determined. In splenectomized animals, the number of neutrophils significantly increased 8 months after surgery. The greatest phagocytic activity of neutrophils, however, was observed in autotransplanted animals of the same age. In splenectomized animals, erythrocyte volumes were significantly higher in the second postoperative month, but normalized by the eighth month. In conclusion, spleen autotransplantation has some beneficial effects, including clearing erythrocytes and preserving the phagocytic activity of neutrophils in peripheral blood.

Resistência de ratos à peritonite fecal quando submetidos a esplenectomia e auto-implante do baço no retroperitônio

OBJETIVO: O estudo foi desenvolvido para avaliar os efeitos do autotransplante esplênico na proteção contra sepse abdominal em ratos Wistar jovens e adultos. MÉTODOS: Foram utilizados 54 ratos Wistar jovens e adultos (90 e 180 dias respectivamente) sendo distribuídos em 3 grupos: Grupo Sham, onde os animais eram submetidos a laparotomia com manipulação de alças apenas (n=6 animais jovens adultos), Grupo Esplenectomia, no qual os animais eram submetidos a esplenectomia total (n=10 animais jovens e adultos) e Grupo Auto-implante, onde os animais eram submetidos a esplenectomia total e um terço do baço era implantado em uma bolsa no retroperitônio (n=10 animais jovens e adultos). Após três meses os animais eram submetidos a nova laparotomia com ligadura e perfuração do ceco para estimular a sepse abdominal e acompanhados até o momento do óbito para estabelecimento de uma curva de mortalidade. RESULTADOS: Houve recuperação do baço implantado em todos os animais. Não houve diferença significativa entre o tempo de óbito entre os grupos. Os animais jovens aparentemente tiveram uma melhor resposta embora não estatisticamente significativa. CONCLUSÃO: Este estudo demonstrou que o auto-implante de baço no retroperitônio não provê proteção efetiva contra sepse abdominal em comparação aos ratos esplenectomizados.

Morfologia e função fagocitária de implante esplênico autógeno regenerado em ratos

Objetivo: O objetivo deste trabalho é analisar a regeneração morfológica de tecido esplênico auto-implantado em ratos Wistar, verificando a função fagocitária bacteriana de seus macrófagos. Métodos: Utilizou-se um modelo experimental com ratos jovens e adultos, de ambos os sexos, submetidos a esplenectomia total combinada com auto-implante de fatias de toda a massa esplênica no omento maior. Dezesseis semanas após, os animais foram inoculados por via intravenosa com suspensão de Escherichia coli AB1157 e, após 20 minutos, foram mortos por dose letal de halotano, sendo submetidos a laparotomia para retirada dos auto-implantes esplênicos. A análise estatística foi realizada com o teste t de Student, com ênfase na comparação da massa de auto-implante esplênico regenerada entre animais jovens e adultos de ambos os sexos. Resultados: Ocorreu regeneração do auto-implante esplênico em todos os animais. Machos jovens e fêmeas adultas apresentaram maior percentual de regeneração. Observou-se aspecto morfológico microscópico semelhante em todos os animais. O tecido esplênico regenerado mostrou as polpas vermelha e branca, com desarranjo arquitetural moderado, bem como folículos linfóides. Os vasos sangüíneos mostravam paredes preservadas, sem sinais de vasculite ou trombose. Foram encontrados macrófagos contendo grumos de bactérias, bem como macrófagos contendo pigmento de hemossiderina intracitoplasmáticos. Conclusão: O auto-implante esplênico, no omento maior, em ratos, adquire a arquitetura macro e microscópica de um baço normal, de dimensão menor e preserva a função fagocitária bacteriana.

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.

Bacterial phagocytosis by macrophage of autogenous splenic implant

Autogenous splenic implant seems to be the only alternative for preservation of splenic tissue after total splenectomy. This work was carried out to analyze the morphologic regeneration of autotransplanted splenic tissue in Wistar rats and to determine the bacterial phagocytic function of their macrophages. We utilized an experimental model with thirty-two rats, of both sexes, submitted to total splenectomy combined with autotransplantation in greater omentum of slices of the whole spleen mass. The animals were divided into two groups: I - young rats weighing 100 to 150 g; and II - adult rats weighing 250 to 300 g. Sixteen weeks later animals were intravenously inoculated with a suspension of Escherichia coli AB1157. Twenty minutes after inoculation, the animals were sacrificed and the splenic autotransplants were removed for morphological study. There was regeneration of autotransplanted splenic tissue in all animals. A similar morphological aspect among all animals was observed, with splenic tissue showing red and white pulps, lymphoid follicles, and marginal zone, with a moderate architectural disarrangement. Macrophages containing gram-negative bacterial aggregates as well as macrophages with hemosiderin pigments within the cytoplasm were observed. Blood vessels showed preserved walls, with no signs of vasculitis or thrombosis. The present results suggest that autogenous splenic implants in the greater omentum of the rat acquire the macro- and microscopic architecture of a normal spleen, with reduced dimensions, and preserve bacterial phagocyte function.

Bacterial clearance after total splenectomy and splenic autotransplantation in rats

Wistar rats submitted to isolated total splenectomy or total splenectomy combined with splenic autotransplantation were inoculated with 99mtechnetium-labeled Escherichia coli. Measurement of isotope uptake in the organs of the mononuclear phagocytic system showed a greater bacterial bloodstream clearance in rats with splenic autotransplantation. Although uptake of bacteria in the spleen was higher in the control group, the number of bacteria remaining in the bloodstream did not differ between groups. These results indicate that splenic autotransplantation preserves the phagocytic function of the spleen.

The functional assessment of autotransplanted splenic tissue by its capacity to remove oxidatively modified erythrocytes

Free radicals and reactive oxygen species have been implicated in the pathogenesis of a variety of hematologic diseases and erythrocyte aging. Aged erythrocytes are removed from the circulation primarily by the spleen. In this study, we aimed to determine the functional effectiveness of autotransplanted splenic tissue by its capacity to remove oxidatively modified erythrocytes from the circulation. Our experimental model in rats includes splenectomy with autotransplantation of 80% of the excised splenic tissue into the omental pouch. In this model, free radical damage was estimated by different parameters of lipid peroxidation such as carbonyl content and thiobarbituric acid reactive substances (TBARS), together with Heinz body formation. Our results have shown that splenic autotransplantation was effective in removing oxidatively modified, aged erythrocytes from the circulation.

Neovascularization of the testicle through spermatic vessels by omental pedicle flap: a new experimental model

The aim of this experimental study in rats was to consider the supplementary role of an omental pedicle flap on the neovascularization of the testicle through the spermatic vessels, for which a Fowler-Stephens procedure had been planned. To compare results, 12 animals had only the spermatic vessels ligated, without an additional procedure (Fowler-Stephens procedure [FS group]), and 12 others had omentopexy of the spermatic vessels of the left testes, with ligation of the vessels 4 weeks later (Fowler-Stephens procedure plus omentopexy [FSO group]). In the sham group (n = 8), only omentopexy of the left spermatic vessels was performed. Six rats served as controls. In each rat, both testes were evaluated by color Doppler ultrasonography to assess capsular and intratesticular blood flow, followed by orchiectomy to determine testicular weights, testicular biopsy scores, and mean seminiferous tubule diameters. Data were analyzed statistically. According to the color Doppler ultrasonography, the testicular blood flow in the FSO group was better than that of the FS group, but was less sufficient than that of the sham and control groups. The testicular weights and biopsy scores for the FSO group were statistically greater than those of the FS group, and less than those of the sham and control groups. There was no significant difference in the mean seminiferous tubule diameters of the FSO and FS groups. The contralateral tests of the four groups did not differ significantly for any parameter. In light of the data available, it is suggested that the omental pedicle flap neovascularizes the testicle through spermatic vessels. Given the high incidence of testicular atrophy associated with Fowler-Stephens orchiopexies, it might be beneficial to perform laparoscopic orchiopexy of testicles neovascularized with omental pedicle flaps as the first-stage procedure.

The effects of experimental splenic autotransplantation and imipenem-cilastatin treatment in postsplenectomy Pseudomonas aeruginosa sepsis

Male Wistar albino rats were allocated to three groups-sham operated (n: 10), splenectomized (n: 20) and splenic autotransplanted (n: 10). Twelve weeks after operation, all were challenged with 1.8 x 10(8) cfu/ml Pseudomonas aeruginosa intranasally. Half of the splenectomized rats received imipenem-cilastatin after 2 h of bacterial challenge. Mortality was then observed for the next 12 days. All animals were autopsied and liver, kidney, spleen and lung specimens were processed for microbiological culture and histopathological examination. In 80% of autotransplanted rats, splenic tissue regeneration was histopathologically verified. Hemoglobin oxidation of erythrocytes increased in splenectomized rats and remained close to control levels in the autotransplanted group. No significant difference was detected between IgM levels of splenectomized and autotransplanted groups. Mortality rates were the same for all groups, except that splenectomized animals given antimicrobial therapy had increased survival rates. In conclusion, it is likely that the spleen has no role in protection against pulmonary sepsis and that only appropriate antimicrobial therapy can protect the splenectomized host from Pseudomonas sepsis.