1.        Introduction

Spleen involvement- Involvement of the spleen is very rare in hydatid disease, among the commonly involved organs in hydatid disease spleen is the third most common organ. The rarity makes it a diagnostic challenge for clinicians, particularly in endemic areas. Splenic hydatidosis has been documented since the beginning of time. Splenic hydatidosis was initially described as an autopsy finding by Berlot in 1790 [1]. It may be discovered by chance or as a result of non-specific complaints.  It is found in South America, Africa, the Middle East, South Europe, India, and Australia, where cattle are raised. Splenic hydatid affects 0.5-4 % of the world's population [2]. Parasitic cysts of the spleen are almost exclusively hydatid cysts. In endemic areas, 50-80% of splenic cysts are echinococcal [3].

Cardiac involvement- Cardiac hydatid cyst localization is very uncommon, accounting for 0.02% to 2% of all hydatidosis patients. Cardiac involvement can arise as a result of the systemic or pulmonary circulation, or as a result of direct extension from nearby structures. A hydatid cyst can appear anywhere on the heart. The cyst's size, location, and integrity all play a role in the manifestations. Although cardiac hydatid cysts are usually asymptomatic for years, they can occasionally cause life-threatening clinical problems. We describe a left ventricular hydatid cyst that resulted in acute coronary syndrome in our study.

Morphology and Pathophysiology

Echinococcus granulosus (EG) causes the most prevalent form of hydatid disease in people; it is a localized cystic disease that most usually affects the liver and lungs. Other types of Echinococcus are, E. multilocularis, E. vogeli, and E. oligarthrus, [4]. Adult tapeworms are little tapeworms with a length of 3 to 6 mm. It is made up of three segments: (i) head or scolex, (ii) a neck, and (iii) a strobila with three segments (the first is immature, the second is adult, and the last is gravid). The egg is ovoid-shaped and includes three pairs of hooks in the form of a hexacanth embryo. Hydatid disease is a zoonotic infection that affects humans. Echinococcus has a definitive host (typically dogs or kindred species) and an intermediate host in its life cycle (such as sheep, goats, or swine). Humans are merely incidental hosts, with no bearing on the transmission cycle. Adult E. granulosus tapeworms are most commonly detected in dogs and other canids. The adult tapeworm lives in the final host's small intestine. The tapeworm is made out of proglottid segments that create parasite eggs with embryos inside (oncospheres). The eggs are released with the definitive hosts' faces on them. The intermediate host and humans consume them. Hexacanth embryos hatch in the duodenum. In around 8 hours, the embryos dug their way through the intestinal wall and into the portal vein's radicles. The portal vein transports the embryos to the liver, where they are halted in the sinusoidal capillaries (first filter). Some embryos may make their way into the pulmonary circulation via hepatic capillaries (second filter). A few embryos may pass through the pulmonary embryos and into the general bloodstream, where they may lodge in numerous organs such as the spleen, heart, lung, kidney, and so on. There has been conjecture about the parasite's various routes to the spleen; the arterial route appears to be the most reasonable and would assist to explain the parasite's rare presence because it would need the parasites to pass through both hepatic and pulmonary filters. Transcoelomic spread from other organs, especially rupture superficial liver hydatid cyst, is another route [5]. Some researchers believe that the embryo migrates from the portal vein to the splenic vein, which reaches the spleen when the intraabdominal pressure is high [6]. Embryos can also enter the lacteals and enter the systemic circulation via the cisterna chyli. Isolated splenic hydatid is uncommon, even in endemic locations, accounting for (0.8–4%) of all human hydatid cases while accounting for (5.8%) of all instances of abdominal hydatid [7]. The cyst expanded slowly over several years, 0.3 cm-1 cm/year is the rate of growth [7], before reaching a size that could be clinically diagnosed, which characterized the syndrome [8]. However, throughout any time of cyst growth [9], including cystic rupture into the peritoneal cavity, which resulted in the omental or visceral cyst, the beginning of complication moved the disease into an overt condition. Cardiac distribution of hydatid cysts is linked to the vascular supply of distinct myocardial regions (the left coronary artery is prominent) and myocardial mass (the left ventricle has the bigger myocardial mass), with a higher incidence in the left ventricle. Pericardial, endocardial, and intramural cysts are all possible. Hydatid cysts on the right side of the heart tend to expand intracavitarily and sub-endocardially. The left ventricle is the most commonly affected site (75%), followed by the right ventricle (15%), the interventricular septum (5%-9%), the left atrium (8%), the pericardium (8%), the pulmonary artery (7%), and the right atrium (3% -4%). The other species like E. multilocularis are hosted by wild canids (typically foxes), with rodents serving as natural intermediate hosts. Domestic dogs and cats can become infected and pass the virus on to humans or contaminate food with parasite eggs. Dogs and other canids are the definitive hosts for E. vogeli, while pacas and other rodents are the primary intermediate hosts. Polycystic hydatid disease is caused by E. vogeli. The hydatid cyst formed by the three layers The outermost adventitia (pseudocyst) of fibrous tissue, the middle layer of a laminated membrane (ectocyst), and the innermost layer of germinal epithelium (endocyst) it is the cyst's very thin and essential layer that gives rise to (a) the brood capsule containing scolice, (b) the secretion of hydatid fluid, and (c) the formation of the outer layer. The germinal layer produces brood capsules. It starts as a sphere, but it quickly vacuolate and transforms into a vesicle. Within these brood capsules, scolices (numbering 5 to 20 or more) develop. The adult worm's future head is displayed by a completely grown scolex. When the hydatid cyst is swallowed by the definitive host, the scolices successfully attach to the small intestine and develop into adult worms inside the definitive host's intestine.

Hydatid fluid composition: It's a colorless, transparent fluid with a specific gravity of 1005 to 1010. It's likely that the reaction is slightly alkaline. It's made up of sodium chloride, sodium sulphate, sodium phosphate, and succinic acid salts in sodium and calcium. It is antigenic and very poisonous, causing anaphylactic reactions. It could contain hydatid sand, which is nothing more than a granular deposit made up of free scolices and liberated brood capsules.

Anatomy, Physiology & function of the spleen

The spleen is a purple-colored fist-shaped organ that measures around 5 inches long, 3 inches wide, 1.5 inches thick, and about 6 ounces in weight, situated at the upper far left part of the abdomen. & it is covered by the 9th 10th and 11th rib and supplied by the splenic artery and splenic vein which plays an important role in transmitting embryos. The spleen was once thought to be an unnecessary organ because it was not thought to be necessary for life; however, as more information about the negative effects of splenectomy became available, surgeons became more conservative in their approach to splenic disease management, attempting to preserve the spleen and maintain the following functions:

The spleen is a specific location of specialized immunoglobin M (IgM) synthesis in the immune system. The macrophages in the reticulum have a filter function in which they catch cellular and non-cellular debris from the blood, including bacteria, particularly pneumococci. Another key function is "culling," which involves removing old platelets and red cells. They are pitting in which the spleen is involved in removing red cell nuclei and malarial parasites without killing the cell. Another splenic function is iron reutilization. Because up to 30–40% of blood platelets sequester within the spleen, causing post-splenectomy thrombocytosis [10], the spleen can operate as a pooling organ.

Postoperative complications

Spleen—Splenectomy postoperative complications include Haemorrhage after the resection of a big and attached spleen, blood oozing may be continuous and bothersome. Hot packs are the greatest way to stop bleeding from a raw splenic bed. As the final step of the operation, approximating the cut ends of the lienorenal and gastrosplenic ligaments with a continuous suture of fine catgut might substantially improve haemostasis.  Injury to the tail of the pancreas, if extra attention is not given during dissection for hilar vessels, damage to the tail of the pancreas may result. This can result in a dehiscence of the abdominal wound, peritoneal effusion, and a localized abscess. A pancreatic fistula might form if the area has not been drained, and nontechnical complications such as post-splenectomy septicemia or opportunist post-splenectomy infection (OPSI), which can all be avoided with conservative surgery [10]. Due to ligation of the short gastric vessel, gastric fistula can develop due to a reduction in vascular supply to the fundus and greater curvature of the stomach. However, this form of fistula can also develop due to damage to the greater curvature when ligating the short gastric vessel. Thrombosis-An increase in platelet count following splenectomy may increase the risk of postoperative venous thrombosis. This type of thrombosis can happen in the portal, hepatic, or systemic veins. However, this issue does not occur as frequently as one might expect. Bacterial infections with septicemia, especially in young children, rapidly proceed to circulatory collapse and death after splenectomy [11]. Injuries to the bowels include the colon and stomach. With precise dissection techniques, these can be avoided. Injury to the stomach can occur when short gastric arteries are ligated too close to the stomach side. It has two levels of mending during the dissection to separate the lower pole, there is a risk of colonic damage. In a similar way, it is also mended. Slippage of the ligature (splenic artery), hilar dissection, and capsular tear during retraction are all examples of vascular damage (2-3 %). Needs to be sutured, coagulated, or clamped after being identified. Overwhelming post-splenectomy sepsis is characterized by its sudden onset, fast progression of shock, and frequent occurrence of meningitis. It is more common in younger people, although it can also happen years after splenectomy in elderly patients [12]. In splenectomized children and adults, Streptococcus pneumonia is the most common cause of septicemia, accounting for 60% of cases. Another quarter (25 %) is caused by Neisseria meningitides and Haemophilus influenza type b, with the rest caused by Escherichia coli, Streptococci species, Staphylococcus auras, Klebsiella species, and Salmonella species. Due to the increased risk of opportunist post-splenectomy infection (OPSI) in the splenectomized patient, Pneumovax, a pneumococcal antitoxin, should be given two weeks prior to surgery. Athelectasis of the left lower lobe is a common side effect. Pleural effusion may or may not be involved. The existence of a subphrenic abscess or irritation or injury to the left hemidiaphragm are the most common causes. It is critically important to inform the patient about the risks of OPSI and to administer medications for any infections. Antimalarial prophylaxis should be given to splenectomized patients who live in malaria-endemic areas [10].

Heart—There is no postoperative complication has been seen with the Patient of cardiac hydatid cyst and patient has been discharged within 10 days.

2.        Patient and Methods

Ten patients with splenic hydatid cyst underwent splenic-preserving surgery in our center between August 2013 and January 2018. Eight of them are being researched retrospectively, and two are being followed proactively. All patients underwent a clinical evaluation that included a complete medical history, a thorough physical examination, and a thorough investigation. Ultrasonography was used to confirm the diagnosis of splenic hydatid. In certain cases, a computed tomography (CT) scan and magnetic resonance imaging (MRI) were required, and all patients had a chest X-ray to rule out pulmonary hydatid.

Among this one patient complains of typical chest pain for the last 20-25 days, pain is aggravated during walking, heavy lifting, and slowly subsides after rest. The radiograph reveals an increase in the size of the left ventricle and dimensions of the heart. Acute coronary syndrome was revealed by electrocardiogram. Coronary angiography revealed that the pulmonary artery of a patient is fistulated with branches of the right and left coronary artery. A 2D transthoracic echocardiography and DSA were performed on a patient. A floating membrane with a cystic lesion which was originated from the left ventricle wall has been revealed by echocardiography. The diagnosis is confirmed by thoracic magnetic resonance imaging and thoracic computed tomography. As our primary focus was to reveal a hydatid cyst of the spleen, other diagnostic tests have been performed on a patient which confirms cystic lesion at the inferior part of the spleen. In order to resect the cardiac cyst patient was sent to the cardiac surgery department.

2.1.    Clinical Features

a)     Hydatid Spleen

When patients came with upper abdomen pain, primarily in the left upper quadrant or epigastrium, which was the most common symptom of splenomegaly, and palpable mass was the most prevalent Findings, a non-complicated hydatid cyst diagnosis was based on clinical suspicion.

True splenic cysts are often asymptomatic and discovered by chance. Patients with symptomatic compression of the left kidney may have ambiguous upper abdominal fullness and discomfort, early satiety, pleuritic chest pain, left-back or shoulder pain, urine symptoms, Dyspepsia, constipation due to colon pressure, dyspnea due to pressing up of the left diaphragm [13] colon fistula [14], or perforation into the diaphragm or bronchial tree [15] are all possible symptoms.

b)     Hydatid Heart

The clinical presentation of cardiac hydatid cysts varies greatly and is strongly dependent on the cysts' location and size.

Precordial pain is the most prevalent symptom, though it is usually vague and does not resemble angina pectoris. The most serious complication of a cardiac hydatid cyst is rupture into the pericardial sac, which can result in cardiac tamponade, anaphylactic shock, or pericarditis.

Cardiac echinococcosis can potentially induce massive pulmonary or systemic embolism, pulmonary hypertension, arrhythmia, compression of coronary arteries with consequent myocardial ischemia, valve dysfunction, obstruction of the ventricular outflow tract, and pulmonary hypertension. Right ventricular cysts are more likely to burst, resulting in a pulmonary embolus, anaphylaxis, or sudden death; left ventricular cysts, on the other hand, have a tendency to grow subepicardially.

2.2.    Operative Techniques

There are several techniques to treat hydatid spleen which include splenectomy, laparoscopy, robotic laparoscopy, and spleen preserving surgery, etc. and for cardiac cystic lesion intact endocyst enucleation, total cyst resection, and puncture aspiration cystectomy are procedural method.

a)     Splenectomy: Splenectomy is currently the most common therapeutic option since it has a low rate of morbidity and mortality [3], [15] Cysts, especially larger ones, should be surgically treated due to the constant severe repercussions of rupture. Because the splenic parenchyma is severely diminished due to pressure atrophy and thick fibrous membrane, the literature recommends total splenectomy in bigger cysts, as seen in the hepatic cyst. Splenectomy, on the other hand, is linked to haemorrhage, pancreatitis, stomach injuries, and overwhelming post-splenectomy infection (OPSI), all of which have been documented in the literature. Sepsis-related fatalities occurred in 1.9% of adults and 4% of children who had their spleen removed [8].

b)     Spleen preserving surgery: Partially splenectomy, cyst enucleation, cyst deroofing with Omentoplasty, or external drainage are all popular spleen-preserving procedures. Total splenectomy advocates say that there is a lesser chance of recurrence and postoperative bleeding with this procedure [15]. Total splenectomy, according to proponents of conservative surgery, predisposes to sepsis and should be avoided, especially in children [16]. For superficial cysts restricted to one of the spleen's poles and cysts with significant adhesions, conservative treatments are performed [17]. To avoid overwhelming post-splenectomy infection (OPSI), which has a mortality rate of more than 50%, preserving the spleen should always be attempted in youngsters.

Preoperative preparation was done based on the patient's general health and anesthetic readiness. The abdomen is opened either via a midline or left subcostal incision during a laparotomy performed under a general anesthetic in a supine position. A splenic hydatid cyst has been identified, preoperative peritoneal cavity exploration for undiscovered hepatic or peritoneal hydatid. Isolation of the operational field with hypertonic solution-soaked packs (20 -30 % hypertonic saline), the cyst fluid is aspirated. Re-aspiration after injecting a reasonable amount of (1 % cetrimide) solution and waiting for at least 5 minutes. The spleen isn't required for mobilization, the endocyst is removed and the cavity is washed with normal saline. Taking up residence in the cystic cavity's intracystic drain. Close monitoring of the patient during and after surgery for allergic reactions or other complications. Follow-up with the patient until he or she is discharged from the hospital (3rd–5th) days. Patients should be followed up every month for the first month after surgery, then every six months for the next six months, and then every year for the next three years. After two years, three patients had not been followed upon. The same surgical team performs all of the operations. All surgeries were performed under the influence of albendazole 15 mg/kg/day for one week before surgery and for four months afterward, in three cycles of 28 days each, with one week of rest in between each cycle.

c)      The cysts were discovered in the left ventricular wall and the operation was performed through a median sternotomy. The operative field was wrapped in towels soaked in a 1% povidone-iodine solution, which was also injected into the cysts. On the prominent portion of the left ventricular wall, a longitudinal left ventriculotomy was performed. The germinative membrane was removed after the cysts were opened, and the fistula which was present between the pulmonary artery and coronary artery has been repaired and prophylactic medical therapy with albendazole was started.

3.        Results

They are six men and four girls, ranging in age from five to forty years (mean 23.6 years). In seven cases, hydatid spleen was identified alone, whereas splenic and liver hydatid was identified in three cases, one of which also included peritoneal hydatid affection. The length of stay in the hospital varied from 3 to 5 days. There were no major intraoperative complications or difficulties, and there was no significant postoperative morbidity or mortality. One of the patients gets a fever, which is caused by lung atelectasis and may be treated effectively. Following surgery, one patient develops a wound infection. Although three patients were missed from follow-up after two years, there was no recurrence after 1-3 years of follow-up. Follow-up sonography imaging revealed a reduction in cyst bed size with the elimination of the component, pseudotumor appearance, and a thicker and uneven cyst wall. The obliteration of the cavity was complete, and the spleen was effectively retained, according to patient follow-up over a period of 1-3 years. Figure 1 shows the demographic and clinical data of the patients and figure 2 shows the postoperative complications results.

Table 1: Demographic and clinical characteristics of the study patients

4.        Discussion

The heart and spleen are one of the less common organs to be damaged by hydatid illness. Splenectomy was the standard treatment for splenic hydatid until recently. The spleen was once regarded to be unnecessary because it was not thought to be vital to life. As a result, the surgeons were free to sacrifice the spleen. Increased awareness of the negative consequences of splenectomy [10], particularly the risk of post-splenectomy sepsis (immunological function) and operative risk, made it critical to preserve splenic - parenchyma and function as much as possible [18] and led to a conservative approach to splenic disease management [2]. As a result, doctors are increasingly attempting to spare the spleen and preserve its functioning. The most frequent benign cystic lesion in the spleen is hydatid, which is primarily caused by EG [19]. Despite its rarity, therapy is required due to the severity and frequency of consequences. When treating benign illness, it is now mandatory to try to preserve the spleen and keep it functioning [15]. Despite the fact that cystic inoculation and splenic hydatid draining should always be attempted [19], splenectomy should only be performed when local conditions demand or a technical misshape arises. Despite our optimistic results in our patients, the number of our patients is still limited, and adoption of this option as it is safe and effective in multicentric studies is associated with an increasing number of cases, which will undoubtedly produce correct findings of this surgical option. The spleen hydatid cyst is a rare disorder, and preserving the spleen should always be attempted, especially in children. Surgery is still the most effective treatment for CE, including splenic echinococcosis. Splenectomy has been shown to offer benefits in terms of lowering recurrence and having fewer complications, according to reports [20], [21].

5.        Conclusion

Surgery is still the most effective treatment for a hydatid cyst. In adults, total splenectomy is the recommended treatment because that offers a full cure with a low incidence and mortality rate, but in children, spleen preservation surgery should be considered to prevent OPSI. The viability of eliminating the hydatid cyst of the spleen while preserving splenic functions has been established by our experienced operators. As a result, the potential disaster of a post-splenectomy complication can be avoided. Splenectomy should only be performed when local conditions demand it or when a technical mishap occurs. The best possible treatment for cardiac hydatid cyst is surgical resection even though in an asymptomatic patient, this results in a full recovery and a favorable prognosis. And the cyst which is located superficially can be removed with the beating heart technique.

Acknowledgments

Authors would like to thank Jabir Ibn Hayyan Medical University, Iraq for basic lab facility.

Conflict of interest

All authors declare no conflict of interest.

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