Natural History of Iatrogenic Pediatric Femoral Artery Injury

Autologous and synthetic pediatric iliofemoral reconstruction: a novel technique for pediatric iliofemoral artery reconstruction

Pediatric lower extremity arterial catheterization-related injuries can result in significant long-term morbidity. Revascularization is challenging due to concerns for long-term patency and growth accommodation with synthetic grafts. We describe a novel technique for iliofemoral revascularization using common iliac artery transposition and bridging polytetrafluoroethylene grafts. We treated two children who underwent femoral catheterization resulting in lifestyle-limiting claudication. Both patients experienced immediate resolution of symptoms. Postoperative imaging demonstrated widely patent vasculature. ASPIRE (autologous and synthetic pediatric iliofemoral reconstruction) is a method of pediatric iliofemoral artery revascularization that allows for an autologous artery to span the hip joint, reducing graft thrombosis risk and accommodating patient growth.

Review of surgical treatment of iatrogenic iliofemoral artery injury in the pediatric population after catheterization

Trauma is the leading cause of death in the pediatric population. Although vascular trauma has an incidence of 6% in civilian population, iatrogenic injuries are the leading cause, and the most frequent injured vessel is the iliofemoral sector. However, little information is available and there are no guidelines about its treatment. Therefore, this review aimed to describe the information available concerning pediatric iatrogenic arterial trauma, focusing on the iliofemoral segment and present 3 cases. We described 11 articles with 171 patients, of whom 61% underwent surgery to treat iatrogenic trauma. Mean age was 3.28 years (standard deviation of 3.5 years), and 54% were female. Most iliofemoral injuries occurred after arterial catheterization for hemodynamic monitorization and therapeutic or diagnostic cardiac catheterization (due to congenital heart diseases, including septal defects, tetralogy of Fallot, aortic coarctation, and patent ductus arteriosus). For acute complications, arterial thrombosis was the leading injury, followed by pseudoaneurysm, hematoma, dissection, transection, avulsion, eversion, and combined lesions.

Practice patterns in the management of pediatric iliofemoral arterial thrombosis

BACKGROUND

Acute arterial thrombosis can be life- and limb-threatening. Most pediatric patients with iliofemoral arterial thrombosis are treated successfully with medical therapy; however, expert consensus is limited, and many recommendations are based on the extrapolation of adult data. We aim to understand treatment patterns and long-term outcomes after pediatric acute iliofemoral arterial thrombosis, from which management recommendations can be informed.

METHODS

A single-institution retrospective study of pediatric patients diagnosed with iliofemoral arterial thrombosis from 2009 to 2018 was performed. Multiple parameters of management and follow-up were evaluated. Children anticoagulated for ≤28 days versus >28 days were compared. Data analysis used Fisher exact and Mann-Whitney U tests.

RESULTS

Two hundred thirty-six children were included. Median age at diagnosis was 65 days (interquartile range 17-163), with 207 diagnosed as infants, 15 diagnosed between 1 to 2 years, and 14 diagnosed between 2 to 16 years. The median treatment duration was 28 days (interquartile range 13-42); patients treated for >28 days had a longer time for thrombus resolution, and more follow-up ultrasounds were performed. Limb length discrepancy did not differ between the groups (1.0% vs 6.3%, P = .06), and no patients were documented to have developed peripheral arterial disease over a median 6.5-year follow-up. Multiple treatment strategies were employed, the most common being heparin bridged to enoxaparin (25.0%) and enoxaparin monotherapy (21.6%). Eight patients (3.4%) underwent surgical intervention.

CONCLUSION

Pediatric iliofemoral arterial thrombosis is primarily a disease of infants treated adequately with heparin or enoxaparin, infrequently requires surgical intervention, and is rarely associated with long-term complications. When guided by thrombus resolution on ultrasound, a four-week or shorter course of anticoagulation does not increase the need for surgical intervention or long-term complications.

Iatrogenic vascular trauma and complications of vascular access in children

Vascular access is frequently a critical component of the diagnostic and therapeutic procedures required to manage childhood illnesses, including many emergent conditions and critical illnesses. Vascular access in the pediatric population presents unique challenges, and many clinical and technical factors must be considered to avoid complications that can occur with vascular access procedures. This article reviews various aspects of vascular access and associated iatrogenic trauma in children, including risk factors, management of complications, and preventive measures to avoid complications. It is only with a comprehensive understanding of the topic that vascular access in children can be performed safely, effectively, and efficiently.

Low profile sheaths in pediatric neurointervention: a multicenter experience

BACKGROUND

Pediatric neurointervention is challenged by the appropriateness of adult catheters and devices. This multicenter report on the smallest groin access sheaths offers technical notes and clinical outcomes in the pediatric neurointerventional population.

METHODS

All pediatric neurointerventional cases from 2019 to 2021 were reviewed for use of a 3.3F Pediavascular or a 4F Merit Prelude Ideal low profile sheath. Hospital records were reviewed for complications and technical notes and compared with arterial groin access with the 4F Terumo Pinnacle in infants less than 1 year old, before the low profile sheaths at one author's institution were introduced.

RESULTS

From January 1, 2019 to March 31, 2021 there were 347 procedures performed at Boston Children's Hospital and University of Wisconsin. Forty-four procedures in 26 patients were identified in which a 3.3F (38 cases, 20 patients) or 4F (6 cases, 6 patients) sheath was used. The average age was 2.2 years (1.5 days to 18 years). Retinoblastoma intra-arterial chemotherapy infusion (18 of 44) was the most common indication. The remaining procedures comprised vein of Galen embolization (12), diagnostic cerebral angiography (13), and one preoperative tumor embolization. Morbidity included a groin hematoma and decreased pulses (4.5%). No major groin complications occurred. There was no statistically significant difference compared with the historical cohort (132 procedures), which had seven instances of decreased pulses (5.3%, p>0.05).

CONCLUSION

The 3.3F Pediavascular and 4F Merit Prelude Ideal sheaths are easily incorporated into the pediatric neurointerventionalist's armamentarium for infants and readily accommodate various microcatheters for distal embolization and catheterization.

Ultrasonographic measurements of femoral vessel diameter in neonates weighing less than 2.5 kg

BACKGROUND

Cannulation in low birth weight (LBW) neonates using larger sheaths could increase the risk of vascular injury. This study investigated the relationship between body weight (BW) and diameter of femoral vessels in LBW neonates and whether BW can be used to predict femoral vessel diameter.

METHODS

The cohort included 100 neonates weighing < 2.5 kg (.57-2.42 kg) with a gestational age of 24-39 weeks. Vascular ultrasonography was used to measure diameters of the bilateral femoral arteries (FA) and veins (FV). The cohort was divided into four groups according to weight: group-A, 2-2.49 kg (n = 28); group-B, 1.5-1.99 kg (n = 38); group-C, 1-1.49 kg (n = 21); and group-D, < 1 kg (n = 13); or according to BSA: group-A, BSA > .16 m² (n = 25); group-B, .13-.16 m² (n = 40); group-C, .1-.13 m² (n = 22); and group-D, < .1 m² (n = 13).

RESULTS

The median vessel diameters (mm) in groups A-D according to weight were FA, 1.96, 1.86, 1.78, and 1.53, and FV, 2.30, 2.28, 2.13, and 1.87, respectively. The median vessel diameters (mm) in groups A-D according to BSA were FA, 1.96, 1.86, 1.76, and 1.53, and FV, 2.30, 2.28, 2.05, and 1.87, respectively. There were positive correlations between BW and femoral vessel diameter (correlation coefficient: .56 and .55 between BW and FA and FV, respectively) (p < 0.001), and between BSA and femoral vessel diameter (correlation coefficient: .56 and .55 between BSA and FA and FV, respectively) (p < 0.001).

CONCLUSIONS

BW is a predictor of femoral vessel diameter in LBW newborns. This finding may help to avoid using larger sheath in smaller vessels.

Transradial Neuroendovascular Procedures in Adolescents: Initial Single-Center Experience

BACKGROUND AND PURPOSE

The feasibility and safety of transradial angiography is not established outside the adult literature. The objective of this study was to assess the feasibility and safety of transradial access for neuroangiography in adolescents.

MATERIALS AND METHODS

A retrospective case-control study was performed, comparing transradial neuroendovascular procedures in adolescents (age range, 10-18 years) with an age- and procedure-matched cohort of transfemoral neuroendovascular procedures. Clinical and procedural details, including type of procedure, conversion rate, fluoroscopy time, radiation dose, complications, and readmissions, were reported by descriptive statistics or measures of central tendency and compared using a t test or nonparametric equivalent. A P value < .05 was considered statistically significant.

RESULTS

Twenty adolescents (mean age, 14.6 [SD, 1.7] years, M/F ratio = 9:11) who underwent transradial neuroangiography were compared against 20 adolescents (mean age, 14.4 [SD, 2.1 ] years, M/F ratio = 12:8) who underwent transfemoral neuroangiography. We found no significant difference in procedural success (0% conversion rate), fluoroscopy times (33.7 [SD, 40.2] minutes versus 23.3 [SD, 26.2] minutes, P = .34) and radiation dose (150.9 [SD, 133.7] Gy×cm² and 122.9 [SD, 79.7] Gy×cm,² P = .43) There were 2 self-limiting postprocedural complications in the transradial group. There were no major hemorrhages, need for further interventions, or readmissions in either group.

CONCLUSIONS

The benefits of transradial angiography described for adults can likely be safely extended to adolescents. These are important data before transitioning to smaller children and should be prospectively evaluated in a larger cohort.

External iliac artery thrombosis: an unusual complication of femoral venous catheterisation in a neonate

We report a neonate who developed external iliac artery thrombosis after insertion of femoral venous catheter, without an apparent arterial puncture during the procedure. The baby developed acute limb ischaemia. As there was no improvement despite heparin infusion for 24 hours, thrombectomy was done. Following surgery, the limb perfusion improved gradually in 1 week. However, pulses did not reappear even after antithrombotic therapy for 3 months. There was residual Doppler abnormality in the form of severe narrowing at the origin of superficial femoral artery with reduced flow velocity in superficial femoral, popliteal and tibial arteries. The baby was kept under regular follow-up, with a plan for clinical assessment and Doppler every 6 months and to perform a vascular reconstructive surgery if he develops any clinical feature of chronic limb ischaemia. The baby is now 1 year of age. He is walking normally and there is no limb length discrepancy.

Femoral Artery Thrombosis After Pediatric Cardiac Catheterization

Femoral artery thrombosis (FAT) is an adverse event post-catheterization. We decided to study the incidence and risk factors of FAT before and after initiation of a pulse loss monitoring program. All cardiac catheterization cases performed using femoral arterial vascular access were retrospectively reviewed. The study period was divided into two eras: before (era 1), and after the initiation of the protocol (era 2). The primary outcome was FAT requiring therapy. Univariable and multivariable logistic regression models were used to identify factors associated with FAT. Receiver operating characteristic curve were generated to predict FAT. Our cohort consisted of 2,388 cases including 467 (19.6%) infants weighing < 10 kg. The overall incidence of FAT was 1.7% (n = 41). The incidence of FAT was 3.5 times higher in era 2 (p < 0.001). Multivariable model showed that era, weight, sheath exchange, and coarctation intervention were significantly associated with FAT. Infants younger than 7.7 months and less than 6.7 kg were found to be at highest risk for FAT. Our study shows that the incidence of FAT may be underestimated without a monitoring program. Small infants and coarctation interventions requiring larger sheaths or sheath exchanges are at highest risk for FAT.

Microsurgical vascular bypass in the setting of pediatric limb length discrepancy

Management of pediatric iatrogenic arterial occlusions can be challenging clinically, leading to chronic complications such as claudication and limb length discrepancy. We report the case of a 6-month-old female patient who had experienced iatrogenic right external iliac and common femoral arterial occlusion. At the age of 8 years, she had developed claudication and a limb length discrepancy of 3.2 cm. She underwent common iliac artery to superficial femoral artery and profunda artery bypass via a branched autologous reverse great saphenous vein using microsurgical techniques for the distal anastomoses. In the present report, we have focused on the musculoskeletal improvements, benefits of microsurgery in pediatric vessels, and maximization of epiphyseal perfusion.

Acute limb ischemia following iatrogenic femoral artery injury during orchiopexy

Orchiopexy for undescended testis is a standard procedure in pediatric patients. Intraoperative complications during orchiopexy are rare. Major complications reported include injury to vas deferens or testicular vessels, leading to testicular atrophy. Damage to the femoral artery has not been described in the literature as a complication during orchiopexy. In this report, we describe a case where injury to the right femoral artery leading to acute limb ischemia occurred while performing orchiopexy.

Comparison of isolated venous approach with the standard approach in children undergoing patent ductus arteriosus device closure

BACKGROUND

Transcatheter device closure is a safe procedure recommended in children with patent ductus arteriosus (PDA). While the standard procedure uses arterial and venous femoral access, it poses risk of vascular complications especially in young infants. Isolated venous approach has been tried in a few studies and was found to be non-inferior to the standard technique. In this prospective observational study, we have compared the two vascular approaches of PDA device closure in pediatric patients and have also studied the feasibility of this approach in young children with weight < 6 kg.

RESULTS

PDA device occlusion was performed with either one of the approaches-venous alone (group I) or standard approach (group II) in a total of 135 children enrolled prospectively. The baseline data, procedural outcomes, vascular complications, and radiation dose were compared between the two groups. Fifty-two and 83 children were included in group I and group II, respectively. A total of 22 children (16%) (13 in group I; 9 in group II) had weight < 6 kg. In group II, 6 children (7.2%) had vascular site complications treated with heparin infusion with two children requiring thrombolysis. Another child in group II developed intravascular hemolysis following residual shunt, requiring surgical device retrieval and closure. No significant differences were observed in mean fluoroscopic time (p = 0.472) and air kerma between the two groups (p = 0.989).

CONCLUSION

Transcatheter PDA device closure without arterial access is a feasible and safe option in children including young infants. This technique avoids the risk of vascular complications although requires careful case selection.

Microsurgical Salvage of Acute Lower Limb Ischemia after Iatrogenic Femoral Injury during Orthopedic Surgery in a Pediatric Patient

Acute lower limb ischemia (ALLI) in the pediatric population is rare but may lead to limb loss and life-long complications. We report the technique and outcomes of microsurgical salvage of ALLI in a preterm newborn after open reduction of congenital hip dysplasia. A 2-month-old girl was born premature at week 36 with congenital bilateral hip dysplasia. The initial management attempted was conservative and entailed placement of bilateral Von Rosen splints. The treatment was successful on the left side, but the patient had recurrent unstable hip dislocation on the right side. Subsequently, 2 attempts at close reduction under general anesthesia were done and both were unsuccessful in maintaining the right hip in the acetabulum. Therefore, an open reduction of the right hip was planned through a medial/obturator approach. During the surgical procedure, the neurovascular femoral bundle (including the superficial femoral artery [SFA], femoral vein [FV], and femoral nerve) was accidently transected with subsequent development of ALLI. Therefore, the FV was harvested distally to the injury site and a 4-cm long healthy segment was obtained. It was reversed, flushed with heparin, spatulated at both extremities, and interposed to the SFA in end-to-end fashion using two 9/0 polypropylene interrupted sutures under microscope. Reperfusion of the limb was noted immediately after releasing the vascular clamps. The final ischemia time at completion of the surgical procedure was 6 hr. Thereby, prophylactic 4-compartment fasciotomies were performed in the right leg. The patient tolerated the procedure well and the postoperative clinical course was free from adverse events. Duplex ultrasound examination at 6 weeks after the intervention confirmed sustained clinical success and showed no signs of venous thromboembolism. At the same time, X-ray examination of the right hip confirmed adequate and stable reduction of the joint in the acetabulum. ALLI due to accidental arterial injury during orthopedic surgical procedures for congenital defects in newborns is a rare but potentially devastating complication. Microsurgical salvage is a safe, feasible, and effective option to restore limb flow. Multidisciplinary expertise and meticulous technique are mandatory in order to achieve satisfactory and durable outcomes.

Dual-layer everted saphenous vein patch for pediatric femoral artery repair following ECMO decannulation

Decannulation from pediatric veno-arterial extracorporeal membrane oxygenation (VA-ECMO) involves the removal of large arterial perfusion cannulas from relatively small lower extremity arteries. While these challenging repairs are frequently performed by general pediatric surgeons, there is little standardization with regard to vascular techniques within the pediatric surgery training paradigm, resulting in variability in the repair of these arteriotomies and potential future consequences for lower extremity perfusion and growth. Herein we present a technique for repair of large common femoral arteriotomies following removal of ECMO perfusion cannulas utilizing a dual-layer patch of ipsilateral saphenous vein harvested via the arterial cutdown incision. This vein segment is everted to maximize endothelial surface area of the patch and dual layered to provide additional support against aneurysmal degeneration. The described technique is an effective repair of arteriotomy following VA-ECMO decannulation, which minimizes vascular complications and is an accessible technique to those without advanced vascular surgical training. LEVEL OF EVIDENCE: Level IV; operative technique description with small case series.

Natural history of acute pediatric iliofemoral artery thrombosis treated with anticoagulation

OBJECTIVE

Acute iliofemoral artery thrombosis (IFAT) can occur in critically ill neonates and infants who require indwelling arterial cannulas for monitoring or as a consequence of cardiac catheterization. Guidelines suggest treatment with anticoagulation, but evidence supporting the optimal duration of therapy and the role of surveillance ultrasound is limited. The objectives of this study were to characterize the kinetics of thrombus resolution and to define an appropriate duration of anticoagulation and interval for surveillance ultrasound.

METHODS

This was a single-center retrospective cohort study of pediatric patients with acute IFAT from 2011 to 2019. Medical records and vascular laboratory studies were reviewed. Patients with one or more surveillance ultrasound examinations were included. Thrombus resolution was defined as multiphasic flow throughout the index limb without evidence of echogenic intraluminal material by ultrasound. Time to resolution of thrombus was assessed using Kaplan-Meier analysis.

RESULTS

Fifty-four limbs in 50 patients were identified with acute IFAT. The median age was 9.9 weeks (interquartile range, 3.1-21.7 weeks), with a median weight of 4.2 kg (interquartile range, 3.3-5.5 kg). The majority of limbs (65%) with acute IFAT presented with a diminished pedal Doppler signal, commonly after cardiac catheterization (55%). Forty-eight (89%) limbs had complete arterial occlusion on index ultrasound, and flow could not be detected below the ankle in 48%. The median number of ultrasound examinations per limb was three (range, two to seven), and 61% of limbs had a surveillance ultrasound within 7 days of diagnosis. At 14 and 30 days, 33% and 64% of patients, respectively, treated with anticoagulation had an estimated complete resolution of thrombus. Nine (17%) patients did not receive anticoagulation, and only two of these patients experienced IFAT resolution. At the time of diagnosis, one patient underwent open thrombectomy because of a contraindication to anticoagulation, and one patient was treated with thrombolysis. There were no instances of tissue loss or amputation CONCLUSIONS: Management of IFAT with anticoagulation resulted in successful short-term outcomes. Based on the observed rate of resolution, management should start with anticoagulation, followed by surveillance ultrasound at 2-week intervals. With treatment by anticoagulation, resolution can be expected to occur in one-third of patients every 2 weeks.

[Ultrasound-guided cannulation or by pulse palpation in the intensive care unit]

INTRODUCTION

Ultrasound (US) guidance increases the success rate and decreases complications during central venous catheterisation (CVC). The benefits of US guidance in arterial catheterisation are less clear. The aim of this study is to compare the outcomes of US-guided arterial catheterisation with the traditional landmark (LM) technique in critically ill children.

METHODS

A prospective multicentre study was carried out in 18 Paediatric Intensive Care units in Spain during a 6-months period. Ultrasound guided and landmark techniques were compared in terms of cannulation technical success and immediate mechanical complications.

RESULTS

A total of 161 procedures were performed on 128 patients (78 procedures in the US group and 83 in the LM groups). The median (interquartile range) age and weight of the cohort was 11months (2-52), and 10kg (4-17), respectively. More than half (59.6%) were male. US was used mainly in big (number of beds 11 [8-16] vs 6 [4-10], p < 0,001) and high complexity intensive care units (cardiac surgery program 76.9% vs. 25.6%, P<.001) as well as in smaller children [weight 5.7kg (3.8-13) vs 11.5kg (4.9-22.7), P<.001]. Almost half (49.7%) of the procedures were performed by an inexperienced operator (paediatric resident, or staff with less than 5years of clinical experience in the PICU), and only 24.4% had performed more than 50 US-guided vascular access procedures before the study. There were no significant differences between US and LM techniques in terms of first-attempt success (35.8% vs 33.7%, P=.773), overall success (75.6% vs 71.1%, P=.514), number of puncture attempts [2 (1-4) vs 2 (1-3), P=.667] and complications (16.6% vs 25.6%, P=.243). Adjustment by potential confounders using multivariate regression models did not modify these results. Subgroup analyses showed that US outperformed LM technique in terms of overall success (83.7% vs 62.7%, P=.036) and complications (10,8% vs 32.5%, P=.020) only when procedures where performed by less-experienced operators.

CONCLUSIONS

In this prospective observational multicentre study, US did not improve arterial cannulation outcomes compared to the traditional LM technique in critically ill children. US-guided arterial cannulation may offer advantages when cannulation is performed by inexperienced operators.

Updates in Pediatric Extracorporeal Membrane Oxygenation

Extracorporeal membrane oxygenation is an increasingly used mode of life support for patients with cardiac and/or respiratory failure refractory to conventional therapy. This review provides a synopsis of the evolution of extracorporeal life support in neonates, infants, and children and offers a framework for areas in need of research. Specific aspects addressed are the changing epidemiology; technologic advancements in extracorporeal membrane oxygenation circuitry; the current status and future direction of anticoagulation management; sedative and analgesic strategies; and outcomes, with special attention to the lessons learned from neonatal survivors.

Pediatric Replantation and Revascularization

Replantation and revascularization in the pediatric extremity has unique challenges that provide a fertile field of research and clinical experience. Children regenerate peripheral nerves rapidly, resulting in good sensory and motor function. They adapt well to functional deficits and mismatch errors of reinnervation. The technical aspects of microsurgical care in children can be challenging because the structures are small. Additional technical challenges include preservation of growth centers, prevention of vasospasm, protection of the reconstruction, and psychosocial care. Despite these challenges, children show excellent functional outcomes with minimal complications.

Arterial reconstructions for chronic lower extremity ischemia in preadolescent and adolescent children

OBJECTIVE

Chronic lower extremity ischemia in pediatric patients is uncommon. The intent of this study was to better define the arterial reconstructive options and their long-term durability in preadolescent and adolescent children having clinically relevant arterial occlusions affecting the lower extremity.

METHODS

The medical records of 33 consecutive pediatric patients who underwent lower extremity revascularization for chronic ischemia at the University of Michigan from 1974 to 2016 were reviewed. Patients were categorized by age, clinical manifestation, surgical intervention undertaken, and outcomes.

RESULTS

Operative treatments involved 26 preadolescent children (mean age, 6.1 years; range, 3-9 years) and 7 adolescent children (mean age, 13.9 years; range, 10-17 years). Occlusions were due to earlier injury related to catheter (14), cannula (2), or both catheter and cannula (14); penetrating trauma (2); and vasculitis (1). Preoperative manifestations included symptomatic extremity ischemia (25), growth retardation manifested by documented limb length discrepancies (21), and scoliosis (5). Primary arterial reconstructions were delayed after the precipitating vascular event an average of 5.3 and 11.2 years in the preadolescent and adolescent children, respectively. Primary procedures involved revascularizations of 36 extremities (in preadolescents and adolescents) including autologous vein (26/5), polyethylene terephthalate (Dacron; 1/0), and expanded polytetrafluoroethylene (0/3) bypasses and vein patch angioplasty (0/1). Vein grafts traversing the abdominal cavity (15) were wrapped with a synthetic mesh. Excluding one early graft occlusion, there were no major early postoperative complications after the primary procedures. Secondary operations followed 31% of the primary operations, being performed an average of 8.8 and 6.7 years later (in 8 preadolescent and 3 adolescent children, respectively) for late graft occlusions (6), graft stenoses (3), aneurysmal vein grafts (2), and anastomotic pseudoaneurysm (1). The unassisted primary graft patency rate was 69%, and the assisted secondary graft patency rate was 94%. Symptomatic ischemia resolved in all but two children. Mean postoperative ankle-brachial indices improved to 1.08 from 0.76 preoperatively. Among children having postoperative documentation of limb lengths, the limb length discrepancies became less (11), were unchanged (1), or progressed (3). Follow-up averaged 8.0 years. There was no operative mortality in this experience.

CONCLUSIONS

Primary lower extremity arterial reconstructions in children with chronic lower extremity ischemia can be successfully undertaken with excellent results. Nevertheless, the potential for late primary graft failures, evident in nearly a third of this experience, mandates careful long-term follow-up and may necessitate secondary interventions to maintain satisfactory outcomes.