To flip or not: Case series of coronary angioplasty in patients with right-sided heart.

Coronary angioplasty in patients with a right-sided heart may be difficult due to challenges in engaging the coronary arteries, interpreting angiogram, and further delivering intracoronary therapies. We present our experience of percutaneous coronary intervention in two cases and propose a practical algorithm to approach cardiac catheterization in these patients.

Molecular Pathways and Animal Models of Defects in Situs.

Left-right patterning is among the least well understood of the three axes defining the body plan, and yet it is no less important, with left-right patterning defects causing structural birth defects with high morbidity and mortality, such as complex congenital heart disease, biliary atresia, or intestinal malrotation. The cell signaling pathways governing left-right asymmetry are highly conserved and involve multiple components of the TGF-ß superfamily of cell signaling molecules. Central to left-right patterning is the differential activation of Nodal on the left, and BMP signaling on the right. In addition, a plethora of other cell signaling pathways including Shh, FGF, and Notch also contribute to the regulation of left-right patterning. In vertebrate embryos such as the mouse, frog, or zebrafish, the specification of left-right identity requires the left-right organizer (LRO) containing cells with motile and primary cilia that mediate the left-sided propagation of Nodal signaling, followed by left-sided activation of Lefty and then Pitx2, a transcription factor that specifies visceral organ asymmetry. While this overall scheme is well conserved, there are striking species differences, including the finding that motile cilia do not play a role in left-right patterning in some vertebrates. Surprisingly, the direction of heart looping, one of the first signs of organ left-right asymmetry, was recently shown to be specified by intrinsic cell chirality, not Nodal signaling, possibly a reflection of the early origin of Nodal signaling in radially symmetric organisms. How this intrinsic chirality interacts with downstream molecular pathways regulating visceral organ asymmetry will need to be further investigated to elucidate how disturbance in left-right patterning may contribute to complex CHD.

Establishment of Cardiac Laterality.

Formation of the vertebrate heart with its complex arterial and venous connections is critically dependent on patterning of the left-right axis during early embryonic development. Abnormalities in left-right patterning can lead to a variety of complex life-threatening congenital heart defects. A highly conserved pathway responsible for left-right axis specification has been uncovered. This pathway involves initial asymmetric activation of a nodal signaling cascade at the embryonic node, followed by its propagation to the left lateral plate mesoderm and activation of left-sided expression of the Pitx2 transcription factor specifying visceral organ asymmetry. Intriguingly, recent work suggests that cardiac laterality is encoded by intrinsic cell and tissue chirality independent of Nodal signaling. Thus, Nodal signaling may be superimposed on this intrinsic chirality, providing additional instructive cues to pattern cardiac situs. The impact of intrinsic chirality and the perturbation of left-right patterning on myofiber organization and cardiac function warrants further investigation. We summarize recent insights gained from studies in animal models and also some human clinical studies in a brief overview of the complex processes regulating cardiac asymmetry and their impact on cardiac function and the pathogenesis of congenital heart defects.

Human Genetics of Defects of Situs.

Defects of situs are associated with complex sets of congenital heart defects in which the normal concordance of asymmetric thoracic and abdominal organs is disturbed. The cellular and molecular mechanisms underlying the formation of the embryonic left-right axis have been investigated extensively in the past decade. This has led to the identification of mutations in at least 33 different genes in humans with heterotaxy and situs defects. Those mutations affect a broad range of molecular components, from transcription factors, signaling molecules, and chromatin modifiers to ciliary proteins. A substantial overlap of these genes is observed with genes associated with other congenital heart diseases such as tetralogy of Fallot and double-outlet right ventricle, d-transposition of the great arteries, and atrioventricular septal defects. In this chapter, we present the broad genetic heterogeneity of situs defects including recent human genomics efforts.

Wakefield's Harm-Based Critique of the Biostatistical Theory.

Jerome Wakefield criticizes my biostatistical analysis of the pathological-as statistically subnormal biological part-functional ability relative to species, sex, and age-for its lack of a harm clause. He first charges me with ignoring two general distinctions: biological versus medical pathology, and disease of a part versus disease of a whole organism. He then offers 10 counterexamples that, he says, are harmless dysfunctions but not medical disorders. Wakefield ends by arguing that we need a harm clause to explain American psychiatry's 1973 decision to declassify homosexuality. I reply, first, that his two distinctions are philosophic fantasies alien to medical usage, invented only to save his own harmful-dysfunction analysis (HDA) from a host of obvious counterexamples. In any case, they do not coincide with the harmless/harmful distinction. In reality, medicine admits countless chronic diseases that are, contrary to Wakefield, subclinical for most of their course, as well as many kinds of typically harmless skin pathology. As for his 10 counterexamples, no medical source he cites describes them as he does. I argue that none of his examples contradicts the biostatistical analysis: all either are not part-dysfunctions (situs inversus, incompetent sperm, normal-flora infection) or are indeed classified as medical disorders (donated kidney, Typhoid Mary's carrier status, latent tuberculosis or HIV, cherry angiomas). And if Wakefield's HDA fits psychiatry, the fact that it does not fit medicine casts doubt on psychiatry's status as a medical specialty.

Radiofrequency ablation of persistent atrial fibrillation in a patient with situs inversus totalis and interrupted inferior vena cava.

INTRODUCTION: Catheter ablation of atrial fibrillation (AF) has emerged as the most effective therapy. However, rare anatomical abnormalities such as situs inversus totalis, dextrocardia, or interrupted inferior vena cava can make ablation challenging. METHODS AND RESULTS: We report a case of a 55-year-old woman with situs inversus totalis, dextrocardia, surgical atrial septal defect repair, left-sided dual chamber pacemaker in place, and symptomatic recurrent persistent AF who underwent successful pulmonary vein and posterior wall isolation by the superior access from the left internal jugular vein. CONCLUSIONS: It is a feasible and safe approach with support of transesophageal echocardiography and multiple emerging technologies.

Novel homozygous variant in ARL2BP associated with retinitis pigmentosa, situs inversus, and male infertility in a Chinese patient.

ARL2BP is a ciliary gene associated with multiple ciliopathy phenotypes. On comprehensive clinical examinations using molecular methods, we identified a Chinese patient from a consanguineous family carrying a novel homozygous variant c.22_23delAG (p.S8Lfs*10) in ARL2BP, presenting with retinitis pigmentosa (RP), situs inversus totalis, and oligozoospermia. Situs inversus and male infertility have never been reported in the same patient with ARL2BP variants; therefore, this a novel ARL2BP-associated phenotypic triad of RP, situs inversus, and male infertility. Moreover, this patient likely had olfactory dysfunction susceptibility and presented with anosmia. We found reduced patient-derived fibroblast proliferation and ciliary length. Our findings expand the genotypic spectrum and reveal abnormal cell proliferation and ciliogenesis in ARL2BP-associated patients.

Biallelic mutations of TTC12 and TTC21B were identified in Chinese patients with multisystem ciliopathy syndromes.

BACKGROUND: Abnormalities in cilia ultrastructure and function lead to a range of human phenotypes termed ciliopathies. Many tetratricopeptide repeat domain (TTC) family members have been reported to play critical roles in cilium organization and function. RESULTS: Here, we describe five unrelated family trios with multisystem ciliopathy syndromes, including situs abnormality, complex congenital heart disease, nephronophthisis or neonatal cholestasis. Through whole-exome sequencing and Sanger sequencing confirmation, we identified compound heterozygous mutations of TTC12 and TTC21B in six affected individuals of Chinese origin. These nonsynonymous mutations affected highly conserved residues and were consistently predicted to be pathogenic. Furthermore, ex vivo cDNA amplification demonstrated that homozygous c.1464 + 2 T > C of TTC12 would cause a whole exon 16 skipping. Both mRNA and protein levels of TTC12 were significantly downregulated in the cells derived from the patient carrying TTC12 mutation c.1464 + 2 T > C by real-time qPCR and immunofluorescence assays when compared with two healthy controls. Transmission electron microscopy analysis further identified ultrastructural defects of the inner dynein arms in this patient. Finally, the effect of TTC12 deficiency on cardiac LR patterning was recapitulated by employing a morpholino-mediated knockdown of ttc12 in zebrafish. CONCLUSIONS: To the best of our knowledge, this is the first study reporting the association between TTC12 variants and ciliopathies in a Chinese population. In addition to nephronophthisis and laterality defects, our findings demonstrated that TTC21B should also be considered a candidate gene for biliary ciliopathy, such as TTC26, which further expands the phenotypic spectrum of TTC21B deficiency in humans.

Biallelic variants in NUDCD2 associated with a multiple malformation syndrome with cholestasis and renal failure.

NudC-like protein 2 (NUDCD2) is a 4-exon protein-coding gene at 5q34. The protein appears to act in concert with other genes regulating cell migration and microtubule extension. Early studies in model organisms show associations with LIS1, HERC2, and cohesin subunits via a co-chaperone function with Heat shock protein 90 (Hsp90). It is a candidate gene for human pathology. We present two unrelated patients with biallelic variants in NUDCD2. Their phenotypes comprise similar dysmorphic facies, midline brain hypoplasia, hypothyroidism, pulmonary and aortic valve stenosis, severe dysfunction of the liver and kidneys, profound hypotonia, and early death. The cellular analysis demonstrates the absence of the NUDCD2 protein in fibroblasts of one patient with biallelic loss-of-function variants. The data suggest that NUDCD2 deficiency causes this recognizable syndrome that has features of a ciliopathy with additional complications.

Diagnostic challenge of Creutzfeldt-Jakob disease in a patient with multimorbidity: a case-report.

BACKGROUND: Creutzfeldt-Jakob disease (CJD) is a rapidly progressive and ultimately fatal neurodegenerative condition caused by prions. The clinical symptoms of CJD vary with its subtype, and may include dementia, visual hallucinations, myoclonus, ataxia, (extra)pyramidal signs and akinetic mutism. In the early course of disease however, several clinical symptoms of CJD may mimic those of co-existing morbidities. CASE PRESENTATION: We report a male in his 60s with a history of situs inversus totalis and Churg Strauss syndrome, who presented with speech fluency disturbances, neuropsychiatric symptoms and allodynia, a few months after becoming a widower. Initially presumed a bereavement disorder along with a flare-up of Churg Strauss, his symptoms gradually worsened with apraxia, myoclonic jerks and eventually, akinetic mutism. MRI revealed hyperintensities at the caudate nucleus and thalami, while the cerebrospinal fluid was positive for the 14-3-3 protein and the real-time quick test, making the diagnosis of CJD highly probable. This case illustrates the complexities that may arise in diagnosing CJD when pre-existing multimorbidity may cloud the clinical presentation. We also discuss the potential mechanisms underlying the co-occurrence of three rare conditions (situs inversus totalis, Churg Strauss syndrome, CJD) in one patient, taking into consideration the possibility of coincidence as well as common underlying factors. CONCLUSIONS: The diagnosis of CJD may be easily missed when its clinical symptoms are obscured by those of pre-existing (rare) multimorbidity. This case highlights that when the multimorbidity has neurological manifestations, an extensive evaluation remains crucial to establish the diagnosis, minimize the risk of prion-transmission and provide appropriate guidance to patients and their caregivers.

Robotic magnetic navigation-guided pulmonary vein isolation in an atrial fibrillation patient with dextrocardia situs inversus: techniques and potential advantages.

BACKGROUND: Dextrocardia with situs inversus (DSI) is a very rare congenital anomaly. Catheter manipulation and ablation of atrial fibrillation (AF) in patients with this anatomical variant is challenging for the operators. This case report presents a safe and effective AF ablation guided by the robotic magnetic navigation (RMN) system in combination with intracardiac echocardiograhy (ICE) in a patient with DSI. CASE PRESENTATION: A 64-year-old male with DSI was referred for catheter ablation of symptomatic, drug-refractory paroxysmal AF. One transseptal access was achieved via the left femoral vein under the guidance of ICE. The three-dimensional reconstruction of the left atrium and the pulmonary veins (PVs) were performed by the magnetic catheter using the CARTO and the RMN system. Then, the electroanatomic map and pre-acquired CT images were merged. Finally, bilateral circumferential ablation lines were delivered around the ipsilateral PV ostia to achieve complete PV isolation (PVI). CONCLUSIONS: This case demonstrates that AF catheter ablation under the guidance of the RMN system using ICE is feasible and safe in a patient with DSI. Moreover, the combination of these technologies broadly facilitates treatment of patients with complex anatomy, while reducing the risk of complications.

Situs inversus totalis: A challenge for cardiac resynchronization therapy.

Situs inversus totalis (SIT) is a congenital condition in which the major visceral organs are reversed or in a mirror image from their normal positions that affects one per 10,000 live births. It is associated with dextrocardia (DXC) in which the heart is located on the right side of the chest. We present a challenging cardiac resynchronization therapy (CRT) implantation in a 60-year-old man with SIT-DXC, heart failure, extreme bradycardia, wide QRS, and left ventricular (LV) dysfunction. The procedure was complex due to the mirror-image anatomy and the tortuous origin of the coronary sinus (CS) branches that required a subselection catheter for adequate lead implantation.

Situs inversus with dextrocardia and transposition of great arteries.

Transposition of the great arteries with left ventricle outflow tract obstruction in combination with situs inversus totalis and dextrocardia is a very rare anomaly and carries high morbidity and mortality. Only few cases have been reported with this anomaly. We describe a 21-day of infant girl with transposition of the great arteries and mirror image dextrocardia and pulmonary stenosis who underwent successful neonatal arterial switch operation and left ventricle outflow tract obstruction resection following PDA stent implantation.

Salivary Gland Choristoma in External Auditory Canal: A Case Report.

INTRODUCTION: Salivary gland choristomas have been described in the middle ear but tend not to involve the external auditory canal. CASE PRESENTATION: A 6-year-old boy with situs inversus totalis presented with congenital hearing loss in the left ear due to external auditory canal atresia. High resolution computed tomography of the temporal bone demonstrated a soft tissue obstruction of the external auditory canal with a normal middle ear. Histopathologically, this was a salivary gland choristoma. Post operatively the patient had a facial nerve palsy. CONCLUSION: Salivary gland choristomas of middle ear have been reported, but have not been described with external auditory canal atresia and situs inversus totalis.

Three-dimensional laparoscopic treatment of situs inversus totalis combined with gastric cancer: Case report with review of literature.

Situs inversus totalis (SIT) is a rare congenital disease. Due to the abnormal distribution of blood vessels in the organs of SIT patients, the anatomical structure is different from that of normal people, which increases the difficulty of surgery, especially laparoscopic surgery. However, there are few reports on the treatment of SIT combined with gastric cancer surgery by three-dimensional (3D) laparoscopy. Here, we describe a case of SIT combined with gastric cancer who underwent 3D laparoscopy-assisted distal radical gastrectomy in March 2021 and with a brief review of the literature.

Efficacy and safety of ERCP in patients with situs inversus totalis: multicenter case series and literature review.

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) in patients with situs inversus totalis (SIT) is rarely understood due to its rarity. Patient position and endoscope manipulation were the main concerns in published case reports. The aim of this study was to investigate the efficacy and safety of ERCP in SIT patients. METHODS: Patients with SIT who underwent ERCP were enrolled in nine endoscopic centers in China. ERCP procedural details and complications in SIT patients were retrieved from electronic medical record. The data was retrospectively analyzed. RESULTS: From 2011 to 2021, totally 14 patients with SIT undergoing ERCP were identified. The mean age was 56.8 years old and the male-female ratio was 5:2. The main indication for ERCP was common bile duct stones (13/14, 92.9%). All procedure were performed by experienced endoscopists. 21.4% (3/14) of patients were under regular position (prone), while 78.6% under modified position (supine, left or right lateral). Difficult cannulation was occurred in 71.4% (10/14) of patients. The rate of successful cannulation was 85.7% (12/14). Complication occurred in 3 patients (3/14, 21.4%), including 1 bleeding, 1 pneumonia and 1 acute myocardial infarction. No post-pancreatitis or death happened. Compared to patients in modified position, those in prone position had numerically less successful cannulations (66.7% vs. 90.9%) and higher adverse events (33.3% vs. 18.2%). CONCLUSIONS: ERCP in patient with SIT is challenging even for experienced endoscopists, modified patient positions might have potential benefits concerning more successful cannulations and less complications. More case experiences are need for comprehensive understanding of ERCP in patients with SIT.

Situs inversus totalis with local metastasis of gallbladder carcinoma and variation of the common hepatic artery.

BACKGROUND: Situs inversus totalis (SIT) is a rare congenital anomaly characterized by a complete transposition of all the viscera. SIT cases were usually reported because of the presence of tumors, leading to false association between them. Therefore, any research that advances our understanding on SIT is highly required. This study firstly describes a very rare case of SIT with "jumping" metastasis to pancreas of gallbladder carcinoma. CASE PRESENTATION: A 69-year-old female patient presented at our hospital with complaints of one month of epigastric pain was studied. She had not sought for treatment prior the visit. Imaging examinations of this patient revealed SIT and a variation of the common hepatic artery with concomitant tumors of gallbladder and pancreas. However, there was no evidence of distant metastases beyond the abdominal cavity. She underwent a combination of radical cholecystectomy, total pancreatectomy, splenectomy and hepatic artery-splenic artery reconstruction. Histological analyses revealed metastasis of the gallbladder carcinoma in to the pancreas. Although the patient opted against chemotherapy, she survived without tumor for 16 months following the surgery. A review of the current literature on association with SIT and tumor occurrence was presented. CONCLUSIONS: It is a great surgical challenge for the resection of multicenter hepatobiliary and pancreatic tumors in such rare SIT anatomical abnormalities with vascular variants. A reliable surgical plan based on detailed preoperative imaging and intraoperative anatomical exploration is crucial to achieving radical resection.

A rare cause of syncope in patients with situs inversus totalis and corrected transposition of the great arteries: Very late lead perforation.

Situs inversus c-TGA refers to a complex anatomical malformation. The risk of developing AV block increases by 2% per year. Pacemaker lead perforation is a rare but serious complication after pacemaker implantation and that develops more than 1 month is defined as late lead perforation. Here, we presented a case of very late lead perforation that occurred 5 years later after pacemaker implantation in a patient with congenital heart disease who had pacemaker due to AV block. Even in the late period, this complication should be kept in mind in patients with a pacemaker who present with syncope.

The Prenatal Origins of Human Brain Asymmetry: Lessons Learned from a Cohort of Fetuses with Body Lateralization Defects.

Knowledge about structural brain asymmetries of human fetuses with body lateralization defects-congenital diseases in which visceral organs are partially or completely incorrectly positioned-can improve our understanding of the developmental origins of hemispheric brain asymmetry. This study investigated structural brain asymmetry in 21 fetuses, which were diagnosed with different types of lateralization defects; 5 fetuses with ciliopathies and 26 age-matched healthy control cases, between 22 and 34 gestational weeks of age. For this purpose, a database of 4007 fetal magnetic resonance imagings (MRIs) was accessed and searched for the corresponding diagnoses. Specific temporal lobe brain asymmetry indices were quantified using in vivo, super-resolution-processed MR brain imaging data. Results revealed that the perisylvian fetal structural brain lateralization patterns and asymmetry indices did not differ between cases with lateralization defects, ciliopathies, and normal controls. Molecular mechanisms involved in the definition of the right/left body axis-including cilium-dependent lateralization processes-appear to occur independently from those involved in the early establishment of structural human brain asymmetries. Atypically inverted early structural brain asymmetries are similarly rare in individuals with lateralization defects and may have a complex, multifactorial, and neurodevelopmental background with currently unknown postnatal functional consequences.

Rare spontaneous monochorionic dizygotic twins: a case report and a systematic review.

BACKGROUND: Monochorionic dizygotic twins are a rare condition, mostly related to assisted reproductive technology. This type of twinning is burdened by the same risk of pregnancy complications found in monochorionic monozygotic pregnancies. CASE PRESENTATION: We report a case of spontaneous monochorionic dizygotic twins sharing situs inversus abdominalis and isolated levocardia, with only one twin affected by biliary atresia with splenic malformation syndrome. We also conducted a literature review of the 14 available documented monochorionic dizygotic twin gestations spontaneously conceived. CONCLUSIONS: It is still unclear how this unusual type of twinning can occur in spontaneous conception. The evidence so far suggest the importance to timely diagnose the chorionicity, in order to adequately manage the typical complications associated with monochorionicity.