Circumferential Constriction Research Articles

A Rare Case Report of Constriction Band Syndrome at the Wrist in a Child (Dhaga Syndrome)

ABSTRACT There are instances when elastic/thread bands are worn on the wrist, especially in infants or children in certain communities for either decorative or religious purposes. In case, it is worn for a long time, it burrows through the skin and soft tissues while going completely un-noticed, causing constriction and resulting in distal edema and loco-regional infection. The rare case discussed here is of a 3 years old female child who presented with circumferential constriction, swelling, and discharging sinuses around the right wrist for 7 months. The case was diagnosed on MRI and subsequently successfully managed surgically. The clinico-radiologic features and details of the case are discussed herein.

A CASE OF HAIR THREAD TOURNIQUET SYNDROME OF THE TOE IN A MALE NEWBORN

Hair-thread Tourniquet Syndrome (HTTS), despite being widely reported, is often not well recognized. It is a rare surgical emergency. This syndrome involves the external, mechanical, circumferential constriction of an appendage by human hair, typically a digit, leading to a condition similar to compartment syndrome. If not treated promptly, it can lead to prolonged ischemia, potentially causing tissue necrosis or autoamputation of the affected digit. Herein, we report a four-day-old newborn from a low socioeconomic background was admitted with fever and feeding refusal. Clinical examination revealed a swollen and red big 4thtoe with a hair-thread tourniquet. No signs of toe ischemia were noted. A diagnosis of maternal-fetal infection with a meningeal focus was made, along with toe tourniquet syndrome. Radiography showed no bone lesion. The patient was treated with antibiotics and a healing cream.

Abstract 415: Standard versus Early Abdominal Counter-Constriction During Circumferential CPR

Introduction: Circumferential constriction CPR (CC-CPR) applied by pneumatic vest may be superior to standard sternal compression, and the addition of alternative pumping modalities may further enhance efficacy. Interposed abdominal counterpulsation (IAC-CPR) CC-CPR is one such modality. Early canine studies of IAC reported greater efficacy when the abdominal counterpulsation was started 30% before the thoracic compression, rather than fully counterphase timing as is used clinically. This may be thought of as “Abdominal Preload” IAC (Pre-CPR). Hypothesis: Addition of IAC-CPR to CC-CPR may be associated with improved perfusion pressures, and Pre-CPR may be even more effective. Methods: We compared CC-CPR to IAC-CPR and Pre-IAC in a porcine model of VF (n=6). In IAC-CPR, the constrictions are fully counterphase. In Pre-IAC, abdominal constriction is initiated 30% before thoracic constriction. Alternating 30 second epochs of each treatment were applied via a circumferential abdominal vest. Aortic (Ao) and Right Atrial (RA) pressures were measured by micromanometer catheters. IAC-CPR and Pre-CPR end-epoch pressures were each compared to preceding CC-CPR end-epoch pressures. Results: Addition of IAC-CPR and Pre-IAC to CC-CPR were both associated with similar, significant increases in CPPs. However, the source of these improvements differed (See Table 1). For IAC-CPR, the increase appeared to result from an Ao increase greater than an associated increase in RA. For Pre-CPR, the increase appeared to be solely due to increased Ao. Limitations: Small sample. Surrogate biomarkers. Non-human model. Conclusions: The addition of pulsatile abdominal counter-constriction to vest CC-CPR may be a promising path to multimodality, regardless of the particulars of cycle timing. We do not confirm earlier observations that Pre-CPR may be superior to IAC-CPR.

Abstract 169: End Tidal CO2 In Multimodal Vest CPR

Introduction: Circumferential constriction vest CPR is more effective at creating forward blood flow than traditional sternal compression only CPR. Active compression-decompression plus the impedance threshold device CPR (ACD-ITD-CPR) incorporates multiple hemodynamic pump mechanisms and also appears more effective. We have developed a new multimodal CPR that combines vest CPR with additional pump mechanisms, one of which is abdominal counterpulsation. Traditional coronary perfusion pressure (CPP) has not been validated during CPR that incorporates compression modalities applied during the relaxation phase. End tidal carbon dioxide (ET-CO2), however, is an indicator of forward blood flow during CPR that is unaffected by relaxation phase compressions. Hypothesis: Multimodal vest CPR that incorporates multiple pump mechanisms may be more effective than standard alternatives as indicated by ET-CO2. Methods: Utilizing a porcine model of ventricular fibrillation, we measured ET-CO2 in: 1) traditional sternal compression CPR (S-CPR), 2) active compression-decompression plus the impedance threshold device CPR (ACD-ITD-CPR) and 3) a new multimodal CPR comprised of circumferential constriction plus abdominal counterpulsation and active sternal decompression (MM-CPR) . After onset of cardiac arrest, 1 min. epochs of each CPR were randomly performed. Results: Seven experiments were performed with a mean number of epochs per experiment of 7. The mean (M + SD) ET-CO2 for S-CPR was 9 + 3 mmHg, for ACD-ITD-CPR 12 + 6, and for MM-CPR 19+8 (P<.05). Conclusions: Multimodal CPR comprising circumferential constriction plus abdominal counterpulsation and active sternal decompression is a promising new type of non-invasive circulatory support.

Idiopathic focal eosinophilic enteritis associated with ileocaecal and ileal obstruction in a 10‐year‐old warmblood gelding

AbstractA 10‐year‐old, 600‐kg, warmblood gelding was referred due to persistent colic, non‐responsive to medical treatment. Diagnostic evaluation revealed abdominal distention, tachycardia and distended small intestines. Preoperative blood testing revealed an increased packed cell volume and normal total white cell count, whereas an abdominocentesis revealed raised peritoneal fluid lactate. Exploratory laparotomy was performed and revealed a circumferential band of thickened tissue and hyperaemia in the distal jejunum, as well as marked wall thickening of the distal ileum and ileocaecal valve, leading to complete luminal obstruction. Due to financial constraints and complications associated with jejuno‐caecostomy, the owner requested the horse to be humanely euthanased. Postmortem examination findings revealed a circumferential constriction of the distal ileum and ileocaecal valve. Histopathology of the affected segments was characterised by a large population of eosinophils within the mucosa, submucosa and muscularis layers in conjunction with severe submucosal oedema. A diagnosis of idiopathic focal eosinophilic enteritis was made.

Multiple Continuous Y-to-V–Plasties for Excision and Reconstruction of Constriction Band Syndrome: Case Series and Description of Surgical Technique

Many patients with constriction band syndrome will seek treatment to improve limb function and cosmesis. Although several techniques for excision are reported, cosmetic and functional deficits can persist, including hourglass deformity, lymphedema, and inadequate band excision with resultant neurovascular compromise, which may lead to revision surgery, including amputation. The authors present a novel technique that uses multiple continuous opposing Y-to-V-plasties in a single or staged manner to correct extremity constriction bands. Seven patients with 10 involved extremities were included in this retrospective case series. Patient demographics, associated abnormalities, and operative indications were collected from medical records. The primary outcome measures were primary wound healing and release of the constriction band. Secondary outcomes measures were perioperative complications and the need for revision surgery. All patients achieved primary closure with excellent healing in one or two stages. No infections or scar complications occurred, and no revision surgery of the band was required. One patient had mild indentation of scar tissue after their second stage, which improved with scar massage. One patient who had preoperative sciatic compression neuropathy and an insensate foot secondary to band constriction developed chronic calcaneal osteomyelitis requiring a subsequent Syme amputation. Postoperative lymphedema occurred in two patients, which resolved with the use of compression bandages over several weeks. Use of multiple continuous opposing Y-to-V-plasties is a safe and effective technique for adequate constriction band excision without residual hourglass deformity and good functional outcomes for patients with partial or circumferential constriction bands. Therapeutic, IV.

1640 Stridor in An Infant with Double Aortic Arch

Abstract An eleven-month-old infant presented to our casualty with stridor that had been noticed by the parents a few weeks earlier and became increasingly evident lately. They did not recall a specific event when the infant “chocked”, but they denied any recent history of respiratory tract infection. The infant had no relevant medical or surgical history, and he was born full term with normal vaginal delivery. Examination of the infant showed moderate biphasic stridor with both suprasternal and intercostal recessions. Oxygen saturation on room air was 94% and temperature was 37.1°. Chest auscultation revealed bilateral equal air entry, though decreased, with transmitted stridor. No lung crepitations were appreciated. Suspicion of unwitnessed foreign body aspiration arose, and a decision of diagnostic rigid bronchoscopy was taken. Rigid bronchoscopy revealed no foreign body along the tracheobronchial tree, but evident circumferential constriction of the lower trachea was noted with tendency of the tracheal wall to collapse upon withdrawal of the bronchoscope. Following recovery, computed tomography with contrast of the neck and chest was done and a vascular ring, consisting of double aortic arch, was found compressing and narrowing the trachea. Further follow up over the following 6 months showed marked improvement of his distress, and active observation was continued. Conclusions Although foreign body aspiration is the commonest cause of stridor in infants and young children, external compression of the trachea, particularly with vascular rings, should be considered in children with otherwise unexplained stridor.

613 Microsurgical Salvage of Neonatal Upper Limb Ischaemia Subsequent to Intrauterine Brachial Vessel Constriction

Abstract Introduction We report a case of limb salvage due to intra uterine brachial artery thrombosis. Treatment modalities include medical, endovascular, and surgical. Early recognition, prompt institution of appropriate treatment and monitoring is vital to achieve successful revascularisation and prevention of lifelong morbidity. Description A male baby at (36 + 6week) gestation was born to a nulliparous mother with gestational diabetes via uncomplicated elective caesarean section. The child was noted to have a ‘flail’ ischeamic limb post-delivery. There were no palpable pulses in the limb and ultrasonography confirmed thrombosis of the proximal brachial artery. Aetiology was due to dense fibrotic circumferential constriction of the brachial vessels and plexus. Successful revascularisation was achieved with a contralateral interposition reversed great saphenous vein graft. Discussion Neonatal limb ischaemia is a rare disease entity with devastating morbidity- including compartment syndrome, tissue loss, limb loss, reduced limb growth, irreparable neuropathies and Volkmann’s syndrome. The initial diagnosis is based on the characteristic sequelae of ischaemia. Therapy should be individualised based on the clinical presentation. Early recognition, prompt institution of appropriate treatment and monitoring is vital to achieve successful revascularisation and prevention of lifelong morbidity.

Clubfeet and congenital constriction band syndrome

BackgroundClubfeet and constriction band syndrome is a very rare non-idiopathic condition. Treatment is often difficult and the recurrence deformity rate is high. The purpose of this study was to assess the effectiveness of Ponseti method in the treatment of congenital constriction band syndrome accompanied by clubfoot deformity and lymphedema.Case presentationWe are presenting an interesting case of bilateral clubfeet and congenital circumferential constriction band syndrome in the lower limb. Ponseti method of correcting the congenital clubfoot deformity was applied. Constriction band release is accomplished by two stages completely excising the fibrous band and multiple two-stage Z-plasties on the right calf.ConclusionThe results of this study indicate that the Ponseti method of gentle, systematic manipulation and weekly cast changes is an effective treatment of non-idiopathic clubfoot distal to congenital amniotic constriction band.

Circumferential constriction ischaemic syndrome (CCIS): A potentially reversible ischaemic condition of lower limb

Circumferential constriction in limb will lead to distal limb ischaemia. This is a potentially reversible condition but it has a drastic consequence if undiagnosed. We described a patient with underlying diabetes mellitus presented with persistent lower limb linear circumferential ulcer and developing subacute limb ischaemia distal to the ulcer. During further wound dressing, a rubber band was detected in the wound. Surgical exploration removed the rubber band and its circumferential constriction effect. As a result, the ulcer healed uneventfully and the distal limb perfusion improved clinically. A scoring index consisted of contributing risk factors was proposed to facilitate the diagnosis. A flow chart was proposed to serve as a treatment protocol to ensure logical and comprehensive management. We hope the proposal of the new term and flow chart can help improve the threshold of recognition and for salvage of potentially devastating limb ischaemia.

One stage release of circumferential constriction band in upper limb with multiple Z-plasty technique: a case report

INTRODUCTION: Congenital constriction band is an uncommon congenital abnormality with multiple disfiguring and disabling manifestations. The widely known management for the correction of congenital constriction band especially in circumferential constriction band is done in a multistage release of constriction band to eluding vascular and lymphatic embarrassment. The purpose of this case report was to present the outcome of one-stage release in terms of safety and aesthetic appearance. CASE DESCRIPTION:Women 28 year old came to outpatient plastic surgery clinic presented with circumferential constriction with no functional disability in her right arm since birth. Excision based on design of multiple Z-Plasty is started 2 cm proximal and distal from constricted band. The multiple Z- Plasty flaps are transposed around each other, changing the direction of the constriction band. Postoperatively, the extremity circulation was normal, and no edema was observed. The range of motion is within normal limits and aesthetically acceptable for the patient. DISCUSSION: Patterson classified constriction ring syndrome into four types, and type II is the most common. In type II Paterson , there are normal full-layer skin structures and no important nerve or blood vessel was affected so an incision completely encircling an extremity would not interfere with distal circulation and provided strong evidence that one-stage resection of constriction band could be performed. Using multiple Z-Plasty for constriction band release leads to improvement of functional and cosmetic appearance of the defect. CONCLUSION: A one-stage release of circumferential constriction band in the upper limb using multiple Z-Plasty is considered as a safe treatment with an aesthetically acceptable result for the patient

Ring depressions in cattle horncores as indicators of traction use – a cautionary note

In this short communication we call attention to the discovery of a ring depression (a circumferential constriction) in the horncore of a feral bull. This discovery casts doubt on the attribution of similar lesions in archaeological deposits as conclusive evidence of ‘cord impressions’ resulting from yoking or reining cattle for traction. Drawing upon evidence of horncore depressions in other species, we suggest that they reflect metabolic problems following horn development; additional research is required to test this hypothesis.

V1-07 CLAMPO-TRACTOR. A NOVEL SELF RETAINING CLAMP RETRACTOR FOR PENILE URETHRAL RECONSTRUCTION: IMPROVING SURGEON ERGONOMICS

You have accessJournal of UrologyReconstruction Lower Tract (I)1 Apr 2017V1-07 CLAMPO-TRACTOR. A NOVEL SELF RETAINING CLAMP RETRACTOR FOR PENILE URETHRAL RECONSTRUCTION: IMPROVING SURGEON ERGONOMICS Pankaj Joshi and Sanjay Kulkarni Pankaj JoshiPankaj Joshi More articles by this author and Sanjay KulkarniSanjay Kulkarni More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.239AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Constant, steady retraction and exposure are important for penile surgery - including hypospadias repair, urethral reconstruction, and correction of penile curvature. We set out to develop a retractor that would improve surgeon and assistant ergonomics and provide compression at the base of the penis to reduce blood loss. We describe this novel self-retaining penile retractor and our initial experience in its use. METHODS This retractor is made of medical grade stainless steel. It has three components – a fixed hemostatic clamp attached to a scale, with also houses an artery forceps. This forceps moves along the scale to adjust the traction on the penis. The clamp is flat and compressive. The arms are non-traumatic and do not cause circumferential constriction. A stay suture taken through the glans is engaged by the artery forceps, and the height adjusted according to the penile length. The retractor has been used by reconstructive urologists in India, Turkey, Australia, Kuwait, Indonesia, and the United States of America. RESULTS A total of 37 reconstructive cases were performed using this penile retractor (23 redo hypospadias repairs, 7 complex penile urethroplasties, 4 penile urethrocutaneous fistula repairs, and 3 surgeries for correction of Peyronie's disease). For each case, surgeons were asked to score the retractor on a 4 point scale: 1. Extremely Non satisfactory, 2. Not Satisfactory, 3. Satisfactory, 4. Extremely Satisfactory. The average score was 3.65. Advantages noted were ease of application, reduction of assistant fatigue, stable operative exposure and non-traumatic tissue compression conferring a bloodless field. There were no complications attributable to the device. The main limitation is that it cannot be used for hypospadias proximal to the penoscrotal junction. This retractor is inexpensive, durable and easy to sterilize and can be used on adult and pediatric patients alike. CONCLUSIONS In our experience this retractor has high utility in reconstruction of the penis and penile urethra. It affords improved ergonomics for the surgeon and assistant, which results in shorter operative times and reduced blood loss while avoiding tissue damage. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e69-e70 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Pankaj Joshi More articles by this author Sanjay Kulkarni More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Functional Morphology of the Arm Spine Joint and Adjacent Structures of the Brittlestar Ophiocomina nigra (Echinodermata: Ophiuroidea).

The skeletal morphology of the arm spine joint of the brittlestar Ophiocomina nigra was examined by scanning electron microscopy and the associated epidermis, connective tissue structures, juxtaligamental system and muscle by optical and transmission electron microscopy. The behaviour of spines in living animals was observed and two experiments were conducted to establish if the spine ligament is mutable collagenous tissue: these determined (1) if animals could detach spines to which plastic tags had been attached and (2) if the extension under constant load of isolated joint preparations was affected by high potassium stimulation. The articulation normally operates as a flexible joint in which the articular surfaces are separated by compliant connective tissue. The articular surfaces comprise a reniform apposition and peg-in-socket mechanical stop, and function primarily to stabilise spines in the erect position. Erect spines can be completely immobilised, which depends on the ligament having mutable tensile properties, as was inferred from the ability of animals to detach tagged spines and the responsiveness of isolated joint preparations to high potassium. The epidermis surrounding the joint has circumferential constrictions that facilitate compression folding and unfolding when the spine is inclined. The interarticular connective tissue is an acellular meshwork of collagen fibril bundles and may serve to reduce frictional forces between the articular surfaces. The ligament consists of parallel bundles of collagen fibrils and 7–14 nm microfibrils. Its passive elastic recoil contributes to the re-erection of inclined spines. The ligament is permeated by cell processes containing large dense-core vesicles, which belong to two types of juxtaligamental cells, one of which is probably peptidergic. The spine muscle consists of obliquely striated myocytes that are linked to the skeleton by extensions of their basement membranes. Muscle contraction may serve mainly to complete the process of spine erection by ensuring close contact between the articular surfaces.

Traumatic Sciatic Nerve Injury and Effectiveness of Spinal Cord Stimulation

Submit Manuscript | http://medcraveonline.com needle injury, neuritis, circumferential constriction around nerve fibre by scar tissue, direct nerve fibre damage by neurotoxic agents injected [4]. We had 2 patients with sciatic nerve injury following intramuscular injection. Patients had been injected analgesic intramuscularly to the left buttock region. They were admitted to our clinic with pain, paresthesia and burning sensation along the sciatic distribution and motor weakness at the left leg and also had a drop foot with loss of dorsiflexion of left foot. Patients’ electromygraphy was analysed on left lower extremity, there was nearly complete and complete axonal denervation on common peroneal and posterior tibial division of sciatic nerve respectively. VAS values were recorded 10 and 9 respectively. After the examination sacral 2-3-4 nerve block on left side was performed with fluoroscopy. Dexamethasone and lidocaine were used for block. Eker et al. performed the block to five patients with sciatic nerve injury following intramuscular injection without fluoroscopy. They observed significiant reduction in pain [5]. But we didn’t see any difference on visual analog scale (VAS) values. Anticonvulsant, antidepressant and analgesic agents were addedd to treatment. Despite the invasive procedure and medical treatments, pain persisted. Then it was decided to perform spinal cord stimulation (SCS) as an alternative treatment. SCS was applied between T8-T10 levels. Prior the procedure VAS values were recorded as 10 and 9. They were recorded 3 and 1, after performing SCS trial respectively. There were many clinical studies, reviews and case reports about sciatic nerve injury due to intramuscular injection. Most of them are about the management, surgical and conservative therapies, results of sciatic injection injury. When we checked out the literature, we could’t find any case report like this. Our cases may be first applied SCS for sciatic neuropathy following intramuscular injection. In this case report we present 2 cases who had neuropathic pain due to intramuscular injection which is resistant to invasive and medical theraphies. We observed that the SCS treatment was effective to relieve pain due to sciatic neuropathy. We did not observe any side effects and infection associated with SCS procedure. SCS should be considered as an alternative treatment method that can be used safely for sciatic neuropathy which has immediate response.

Meatal Occlusive Disease in Adult Males: Are There Any Clinical Variations?

Objective: The study aimed to document the types of meatal occlusive disease (MOD) in adult males in terms of its clinical presentation, management and prognosis. Material and Methods: Eighty-six adult males with MOD were assessed during the study period. The patients were divided into Group 1, having meatal opening that was occluded by flimsy adhesions (meatal synechia/adhesive type MOD), and Group 2 that included patients who had circumferential constriction of the meatus (meatal stenosis/constrictive type MOD). All patients underwent meatal dilatation up to 18 Fr followed by self-dilatation for 3 months with topical clobetasol for 4 weeks. Degree of discomfort during self-dilation, improvement in flow rate, International Prostate Symptom Score (IPSS score) and recurrences were recorded at pre-determined intervals. Results: Twenty-eight patients had meatal synechia (Group 1) and 48 had meatal stenosis (Group 2). Discomfort during self-dilatation in Group 1 patients was significantly less; there was improvement in IPSS and peak flow rate (mean follow-up 26.8 months) as compared to Group 2. With dilation alone, no recurrence was noted in Group 1; however, Group 2 showed 62.8% recurrence indicating poor outcome in this subset of patients. Conclusion: MOD in adult males consists of 2 separate clinical entities with different therapeutic outcomes.

A review on the safety of one-stage circumferential ring constriction release.

The study was undertaken to investigate the use of one-stage circumferential ring-constriction release with Z-plasties regarding the safety, aesthetic appearance, and limb function. A thorough review was conducted on all English publications in PubMed during the period of 2001 through 2011. Titles and abstracts were identified using online search engine from National Library of Medicine's PubMed database under the keywords "limb constriction ring," "limb constriction band," "amniotic band," "annular constriction," and "circumferential constriction." We used Boolean operator and field of title. Evaluation was done to search indications, timing of the first surgical intervention, time interval between surgeries, patients' gender, anatomic location of the ring, wound healing problems, and scar quality. Fourteen publications met the criteria. There were 17 patients with 25 ring constrictions in total. Sixteen ring constrictions (64%) were circumferential; nine (36%) were semi-circumferential. Mean age of 14 patients treated with one-stage release was 4.8 years. Six articles mentioned about normal development of postoperative limb function. Mean age of three patients treated with staged release was 10.5 months. Two articles mentioned regained distal muscle function postoperatively. It is confirmed that surgeons may continue the practice to release circumferential CRS in one stage.

Hair tourniquet syndrome: revisited.

Hair tourniquet syndrome is a rare condition. It is an important emergency condition where urgent attention is needed. In this condition, body appendages are strangulated by hair that acts like a tourniquet. A strand or strands of hair act like a circumferential constriction band and subsequently strangulate the body appendages. Commonly affected sites include fingers, toes or even genitals. Failure to identify and release the acute constriction may result in amputation of affected body part. We report two cases of hair tourniquet syndrome of the thumb and toe that were successfully released without complications.

Hair-thread tourniquet syndrome: a case report and review of treatment

Hair-thread tourniquet syndrome (HTTS) is caused by circumferential constriction of an appendage, usually by hair or thread, leading to obstruction of circulation and ischemia. Although not rare, this entity is not discussed extensively in the Dermatology literature. We present a case of HTTS and discuss the demographics and etiology, and review the most current treatment methods.

Babesia divergens and Neospora caninum apical membrane antigen 1 structures reveal selectivity and plasticity in apicomplexan parasite host cell invasion

Host cell invasion by the obligate intracellular apicomplexan parasites, including Plasmodium (malaria) and Toxoplasma (toxoplasmosis), requires a step-wise mechanism unique among known host-pathogen interactions. A key step is the formation of the moving junction (MJ) complex, a circumferential constriction between the apical tip of the parasite and the host cell membrane that traverses in a posterior direction to enclose the parasite in a protective vacuole essential for intracellular survival. The leading model of MJ assembly proposes that Rhoptry Neck Protein 2 (RON2) is secreted into the host cell and integrated into the membrane where it serves as the receptor for apical membrane antigen 1 (AMA1) on the parasite surface. We have previously demonstrated that the AMA1-RON2 interaction is an effective target for inhibiting apicomplexan invasion. To better understand the AMA1-dependant molecular recognition events that promote invasion, including the significant AMA1-RON2 interaction, we present the structural characterization of AMA1 from the apicomplexan parasites Babesia divergens (BdAMA1) and Neospora caninum (NcAMA1) by X-ray crystallography. These studies offer intriguing structural insight into the RON2-binding surface groove in the AMA1 apical domain, which shows clear evidence for receptor-ligand co-evolution, and the hyper variability of the membrane proximal domain, which in Plasmodium is responsible for direct binding to erythrocytes. By incorporating the structural analysis of BdAMA1 and NcAMA1 with existing AMA1 structures and complexes we were able to define conserved pockets in the AMA1 apical groove that could be targeted for the design of broadly reactive therapeutics.