Selective preoperative assessment before early laparoscopic cholecystectomy: A narrative review

Abstract

Early laparoscopic cholecystectomy is recommended for symptomatic gallstone disease, acute cholecystitis and mild gallstone pancreatitis because it reduces recurrent biliary events and avoidable readmission. Formal preoperative assessment remains essential when comorbidity, frailty, medication complexity or anaesthetic concerns require investigation or optimization. Whether every low-risk patient needs a separate clinic-based appointment before early surgery is less certain. This narrative evaluates the evidence relevant to selective preoperative assessment, drawing on guidelines, routine-testing studies, perioperative risk literature and an illustrative five-year United Kingdom Hot Gallbladder Pathway service evaluation involving 511 patients. Current guidance supports individualized investigation but does not define criteria for omitting preassessment. Indirect evidence suggests that structured screening, review of recent clinical information and same-day anaesthetic confirmation may provide a feasible pathway for carefully selected American Society of Anesthesiologists I-II patients without red flags. The United Kingdom service evaluation reported no identified anaesthetic-related adverse event and one non-anaesthetic cancellation, but its retrospective single-trust design cannot establish equivalence, rare-event safety or cost-effectiveness. Selective assessment should therefore be regarded as a governed service model rather than an established standard. Prospective multicentre studies should compare cancellation, perioperative complications, unplanned admission, time to surgery, patient experience, resource use and cost-effectiveness.

Key Words: Laparoscopic cholecystectomy; Preoperative assessment; Anaesthetic assessment; American Society of Anesthesiologists classification; Risk stratification; Perioperative medicine; Hot Gallbladder Pathway; Narrative review

Core Tip: Preoperative assessment is a clinical function. For early laparoscopic cholecystectomy, selected low-risk patients may be suitable for structured screening and same-day anaesthetic confirmation, while patients with American Society of Anesthesiologists III-IV status, frailty, unstable disease, complex medication needs or anaesthetic concerns require formal optimisation. The supporting evidence is mainly indirect. A 511-patient United Kingdom service evaluation demonstrates feasibility but cannot establish safety equivalence or cost-effectiveness. Selective assessment should therefore be introduced only with explicit criteria, anaesthetic governance and prospective audit.

INTRODUCTION

Gallstone disease is a frequent cause of emergency surgical admission, and laparoscopic cholecystectomy is the definitive treatment for symptomatic gallstone disease, acute cholecystitis and mild gallstone pancreatitis. Randomized trials, systematic reviews and international guidance[1-5] support early surgery because it shortens total hospital stay and reduces recurrent biliary events during the waiting period[6,7]. The present review does not re-examine the effectiveness of cholecystectomy; instead, it addresses how preoperative assessment may be organized when early surgery is planned.

Preoperative assessment was developed to prevent patients from reaching the operating theatre with unrecognized or inadequately optimized disease. Its functions include (1) Reviewing comorbidity, medication and previous anaesthetic problems[8-11]; (2) Selecting investigations[12-15]; (3) Assessing functional capacity, frailty and airway risk[16-18]; (4) Planning postoperative care[19-21]; and (5) Communicating with the patient and multidisciplinary team[22-24]. These functions remain indispensable for patients with significant systemic disease or clinical uncertainty.

The delivery model has nevertheless changed. Earlier pathways relied on routine investigations and universal face-to-face attendance. Contemporary perioperative practice favours selective testing and targeted optimization according to the patient and procedure. NICE NG45, for example, recommends that investigations are chosen according to surgical grade and comorbidity rather than applied as a fixed battery[25]. Evidence from routine-testing studies[23,26-29] shows a low clinical yield from indiscriminate investigation in healthy or asymptomatic patients and a risk of false-positive results and further delay[30-32].

This shift raises a narrower question: Whether every patient undergoing early laparoscopic cholecystectomy needs a separate clinic-based anaesthetic appointment when recent emergency-admission information is available. Selective preoperative assessment, as used in this review, means that formal clinic assessment is reserved for patients with risk factors, while low-risk patients undergo documented structured screening and anaesthetic confirmation before induction. It does not mean absence of assessment or removal of anaesthetic accountability[8,9,25].

Direct comparisons of universal and selective clinic attendance before early laparoscopic cholecystectomy are limited. The evidence must therefore be interpreted from perioperative testing, risk stratification and service-evaluation literature. This narrative review summarizes that evidence, presents objective data from a United Kingdom Hot Gallbladder Pathway as an illustrative model, and identifies requirements for safe implementation and future research.

METHODOLOGY

This article is a narrative review rather than a systematic review or meta-analysis. Literature was identified through focused searches of MEDLINE/PubMed, EMBASE and the Cochrane Library, last updated on February 28, 2026. Search concepts included preoperative or pre-anaesthetic assessment, routine preoperative testing, laparoscopic cholecystectomy, acute gallstone disease, ambulatory or day-case surgery, frailty, perioperative risk, digital assessment and artificial intelligence (AI). English-language guidelines, systematic reviews, randomized trials, observational studies and relevant service evaluations were considered, and reference lists of key publications were reviewed. Evidence was selected for clinical relevance to early laparoscopic cholecystectomy and interpreted according to methodological quality, directness and applicability to pathway redesign. Because this was a narrative synthesis, no PRISMA flow diagram, protocol registration or formal pooled analysis was undertaken.

Because direct comparative studies of universal vs selective clinic attendance are scarce, the review distinguishes direct evidence from indirect evidence and local service experience. Selective preoperative assessment is defined here as a pathway in which formal clinic-based anaesthetic assessment is reserved for patients with identified risk factors, while low-risk patients undergo structured screening, review of recent clinical information and anaesthetic confirmation before induction. It does not imply absence of assessment, removal of anaesthetic responsibility or automatic day-of-surgery clearance.

CURRENT GUIDELINE POSITION: AGREEMENT, GAPS AND PRACTICAL INTERPRETATION

Guidelines on gallstone disease support early definitive treatment but do not provide an algorithm for bypassing formal anaesthetic clinic attendance. NICE CG188, WSES 2020, Tokyo Guidelines 2018 and AUGIS guidance recommend timely laparoscopic cholecystectomy in appropriate patients[1-4,33]. Their relevance to this review is contextual; unnecessary delay may hinder early treatment, but these documents do not establish the safety of selective preoperative assessment.

Perioperative guidance is more directly relevant. NICE NG45 recommends selective preoperative testing according to age, surgical grade and comorbidity. The American Society of Anesthesiologists (ASA) practice advisory supports evaluation tailored to the individual patient and procedure[8,9,25]. These recommendations justify risk-based investigation and escalation, but they do not equate selective testing with omission of clinical assessment.

The guideline gap is operational. Institutions considering direct-to-surgery pathways must define eligibility, minimum information requirements, anaesthetic review, escalation criteria and audit outcomes. In the absence of comparative guidance, local implementation should be treated as a governed service innovation rather than an established standard (Table 1)[1-5,9-11].

Table 1 Guideline synthesis relevant to selective preoperative assessment.

Guideline/source	Core recommendation	Relevance to selective assessment	Gap
NICE CG188 gallstone disease[1]	Supports definitive management with laparoscopic cholecystectomy and early surgery in acute presentations	Strengthens the argument that avoidable pathway delay matters	Does not specify anaesthetic clinic criteria
NICE NG45 preoperative tests[2]	Recommends selective testing based on surgical grade and comorbidity	Supports risk-based rather than universal investigation	Focuses on tests rather than full clinic attendance
WSES 2020 acute cholecystitis[3]	Supports early laparoscopic cholecystectomy when feasible	Aligns with streamlined access to surgery	Does not define pre-assessment omission criteria
Tokyo Guidelines 2018[4,5]	Provides severity grading and surgical management principles	Emphasises patient selection and safe cholecystectomy	Does not address direct-to-surgery assessment pathways
ASA preanaesthesia evaluation[10,11]	Evaluation should be appropriate to patient and procedure	Supports tailored evaluation and escalation	Requires local implementation detail
AUGIS acute gallstone pathway[9]	Promotes timely management of acute gallstone disease	Relevant to United Kingdom Hot Gallbladder Pathway design	Implementation varies by resources

ASA: American Society of Anesthesiologists.

ASA CLASSIFICATION AND PERIOPERATIVE RISK STRATIFICATION

ASA Physical Status is widely used because it is simple, familiar and clinically meaningful. It communicates systemic disease burden and correlates with perioperative morbidity and mortality at a population level[9-12]. For pathway design, ASA I-II status is a useful initial filter because these patients generally have absent or mild systemic disease, whereas ASA III-IV patients often require more detailed optimization. However, ASA grade alone is insufficient to determine whether formal preoperative assessment can be omitted.

The limitations of ASA classification are well described. Inter-rater variability exists, particularly at the ASA II-III boundary[10-12]. ASA does not directly incorporate frailty, functional capacity, procedure complexity, airway risk, anticoagulation, social support, cognitive impairment, anaemia, obesity-related hypoventilation or patient preference. In older patients, frailty may predict adverse outcomes independently of traditional comorbidity measures[14-18], and contemporary perioperative guidance recommends explicit frailty screening and multidisciplinary planning for older surgical patients[24]. A patient labelled ASA II may still require formal assessment if there is poor exercise tolerance, unstable symptoms, complex medication management or uncertainty about previous anaesthetic complications.

The practical conclusion is that ASA status should be used as a first step, not as a standalone rule. Selective assessment algorithms should combine ASA class with a structured comorbidity checklist, functional capacity, frailty screening for older adults, medication review, airway history, previous anaesthetic history, recent laboratory results and escalation criteria. This is more defensible than assuming that all ASA I-II patients can safely bypass formal preoperative assessment (Table 2).

Table 2 Risk factors that should trigger formal preoperative assessment despite apparently low American Society of Anesthesiologists class.

Domain	Examples	Rationale
Cardiorespiratory symptoms	Exertional chest pain, unexplained dyspnoea, syncope, decompensated heart failure, unstable asthma/COPD	May alter anaesthetic plan, investigation and perioperative monitoring
Functional capacity/frailty	Poor exercise tolerance, falls, unintentional weight loss, cognitive impairment, dependence in activities of daily living	ASA may underrepresent frailty-related risk
Medication complexity	Warfarin/DOACs, antiplatelets, insulin, immunosuppression, high-dose opioids	Requires perioperative planning and possible bridging/adjustment
Airway/anaesthetic history	Previous difficult airway, malignant hyperthermia risk, severe postoperative nausea/vomiting, previous ICU admission	Requires anaesthetic planning and documentation
Obesity and sleep-disordered breathing	Severe obesity, suspected OSA, obesity hypoventilation symptoms	May influence airway, postoperative monitoring and day-case suitability
Abnormal investigations	Unexplained anaemia, renal impairment, electrolyte disturbance, deranged liver function suggesting CBD stones	May require optimisation, ERCP or altered timing
Social/discharge concerns	No adult escort, poor understanding, language barriers, safeguarding concerns	May affect day-case/discharge safety

ASA: American Society of Anesthesiologists; COPD: Chronic obstructive pulmonary disease; DOACs: Direct oral anticoagulants; ICU: Intensive care unit; OSA: Obstructive sleep apnea; CBD: Common bile duct; ERCP: Endoscopic retrograde cholangiopancreatography.

EVIDENCE QUESTIONING UNIVERSAL ASSESSMENT AND ROUTINE TESTING IN LOW-RISK SURGERY

The strongest evidence relevant to selective assessment comes indirectly from the routine preoperative testing literature. The classic studies by Kaplan et al[27], Narr et al[28] and Turnbull and Buck[29], together with the systematic review by Munro et al[26], found limited value in indiscriminate testing among healthy or asymptomatic surgical patients. Subsequent analyses and guideline summaries have reinforced the same principle; tests should be ordered when the result is likely to alter management, not because a patient is entering a surgical pathway[25,30-32]. Procedure-specific Cochrane evidence from cataract surgery is not directly transferable to laparoscopic cholecystectomy, but it provides a high-volume example in which routine preoperative medical testing increased resource use without improving safety[23]. The transferable lesson is not that assessment is unnecessary, but that low-yield routine processes should be replaced by clinically indicated assessment.

The limitation is that evidence against routine testing is not identical to evidence against preoperative assessment. A clinic appointment includes history, education, medication review, consent reinforcement and discharge planning, not just blood tests. Therefore, the critical question is whether these functions can be delivered safely through another pathway. In patients recently assessed during emergency admission, much of the necessary information may already be available. The incremental benefit of a separate clinic is likely highest when information is incomplete or risk is uncertain, and lowest when the patient is young, fit, recently investigated and clinically stable.

DIRECT EVIDENCE AND AN ILLUSTRATIVE HOT GALLBLADDER PATHWAY DATA

Direct comparative evidence evaluating universal vs selective clinic-based anaesthetic assessment before early laparoscopic cholecystectomy is limited. To provide objective data relevant to selective preoperative assessment, we present findings from a five-year United Kingdom Hot Gallbladder Pathway service evaluation. Although observational and non-comparative, these data provide real-world information on cancellation, recorded anaesthetic outcomes and operational feasibility. Routine-testing studies[23,25-28] support clinically indicated investigation, but testing is only one component of preoperative assessment[29-32]. Consequently, claims regarding cancellation, safety or cost-effectiveness should be based on objective pathway data rather than extrapolation alone.

A five-year service evaluation at North Tees and Hartlepool NHS Foundation Trust included 511 adults undergoing laparoscopic cholecystectomy through a Hot Gallbladder Pathway between January 2020 and January 2025. Of these, 401 patients (78.5%) were classified as ASA I-II and 110 (21.5%) as ASA III-IV. Overall, 334 patients (65.4%) proceeded without formal clinic-based anaesthetic pre-assessment, whereas 177 (34.6%) underwent formal assessment. All ASA III-IV patients were formally assessed. No anaesthetic-related adverse event was identified among the 511 patients. One cancellation occurred (0.2%); it involved an ASA I-II patient and was unrelated to an anaesthetic reason.

These data indicate that selective assessment was operationally feasible in this service. They do not establish equivalence with universal assessment. The evaluation was retrospective, conducted within a single trust and based on clinician selection. It was underpowered to evaluate rare adverse events. ASA grading may have varied between clinicians, and lower-risk patients were preferentially selected to bypass clinic assessment. Waiting time, recurrent admissions attributable to the assessment model, patient-reported outcomes and cost-effectiveness were not measured.

The dataset should therefore be interpreted as an illustrative service-evaluation finding rather than definitive comparative evidence. Its principal contribution is to define a testable pathway. Selected ASA I-II patients without red flags may proceed after structured screening and same-day anaesthetic review, whereas ASA III-IV patients and those with clinical complexity undergo formal assessment. Prospective multicentre comparison is required before this model can be recommended as routine care[34,35]. Selective assessment changes the timing and intensity of assessment so that patients with greater complexity receive formal optimization, while low-risk patients avoid duplicate clinic attendance only when adequate recent information and escalation mechanisms are available.

To our knowledge, no published prospective study has directly compared universal with selective preoperative assessment before early laparoscopic cholecystectomy with respect to day-of-surgery cancellation, perioperative complications or cost-effectiveness. This absence of comparative evidence highlights the need for prospective multicentre evaluation.

HEALTH-ECONOMIC IMPLICATIONS

Selective assessment may alter clinic workload, investigation of use, patient travel and administrative cost, but these effects cannot be assumed. A streamlined pathway could also transfer work to the day of surgery or increase cancellation if screening is inadequate. The relevant economic question is therefore the net cost of the complete pathway, including assessment, investigations, cancellations, unplanned admission and patient-borne costs.

No formal cost-effectiveness analysis was undertaken in the illustrative United Kingdom service evaluation, and direct economic comparisons in this setting are sparse. Future evaluations should adopt a health-system and patient perspective and include pre-assessment clinic contacts, investigations, staff time, patient travel and time costs, cancellations, theatre utilization, unplanned admission, recurrent biliary admission, critical-care use and total pathway cost. Environmental consequences, including avoidable travel and duplicated appointments, may be reported as secondary outcomes but should not be assumed to favour either pathway without measurement.

DIGITAL, TELEPHONE AND AI-SUPPORTED PREOPERATIVE ASSESSMENT

Digital triage, telephone clinics and AI-supported risk prediction may allow perioperative services to capture structured information without requiring every patient to attend a clinic. Electronic questionnaires can screen comorbidity, functional capacity, medication use, allergies, previous anaesthetic history, airway concerns and social support. Integration with electronic patient records can reduce duplication by importing recent blood tests, imaging and admission notes. Telephone or video review can then be reserved for patients with incomplete information or moderate risk. In this model, digital assessment does not replace anaesthetic judgement; rather, it provides an information architecture that may support more consistent, auditable and scalable risk stratification[36-39].

AI and machine-learning models[34,39-41] have shown promise in perioperative risk prediction, including prediction of postoperative mortality and complications[42-45]. However, AI is not a substitute for clinical responsibility. Prediction models may be poorly calibrated outside their development setting, may encode bias and may fail when data are missing or inaccurately entered. Although AI has demonstrated promising predictive performance in perioperative risk stratification, implementation studies showing improvements in patient outcomes, workflow efficiency or cost-effectiveness remain limited. Recent perioperative AI reviews emphasize the same challenge: Predictive performance alone is insufficient unless models are externally validated, transparent, clinically usable and evaluated for real-world impact[34,39,44,45]. AI may therefore support selective assessment by flagging risk or missing information, but it should not autonomously determine whether a patient receives anaesthetic review.

A practical near-term model is digital-first but clinician-led. Electronic screening identifies low-risk, moderate-risk and high-risk patients. Clinicians review exceptions and red flags, anaesthetists retain the final authority and outcome dashboards monitor safety. This model is more realistic and safer than full automation (Table 3).

Table 3 Objective findings and limitations of the illustrative United Kingdom Hot Gallbladder Pathway service evaluation.

Aspect	Objective finding or interpretation
Cohort	511 adults undergoing laparoscopic cholecystectomy, January 2020-January 2025
Risk distribution	401 ASA I-II (78.5%); 110 ASA III-IV (21.5%)
Assessment pathway	334 (65.4%) without formal clinic-based pre-assessment; 177 (34.6%) with formal assessment; all ASA III-IV patients formally assessed
Recorded outcomes	No anaesthetic-related adverse event identified; one cancellation (0.2%), unrelated to anaesthetic factors
Interpretation	Supports feasibility in a selected cohort; does not establish equivalence or safety for rare events
Unmeasured outcomes	Waiting time, attributable recurrent admission, patient-reported outcomes and cost-effectiveness
Key limitations	Retrospective, single-trust, clinician-selected, potential ASA misclassification and rare-event underpowering

ASA: American Society of Anesthesiologists.

PROPOSED RISK-STRATIFIED PATHWAY

A practical pathway should begin at surgical review. Patients with symptomatic gallstone disease requiring early laparoscopic cholecystectomy should undergo structured assessment of diagnosis, severity, comorbidity, medication, previous anaesthetic history, functional capacity, frailty and recent investigations. Patients without red flags, typically those classified as ASA I-II, may be listed directly with documented eligibility and same-day anaesthetic confirmation. Patients with any red flag should undergo formal preoperative assessment before listing. ASA III-IV patients should generally undergo formal multidisciplinary assessment and optimization. The proposed pathway is summarized in Figure 1.

Figure 1 Proposed risk-stratified pathway for selective preoperative assessment before early laparoscopic cholecystectomy. ASA: American Society of Anesthesiologists.

The pathway should include a safety valve. If the anaesthetist identifies a new concern on the day of surgery, postponement should be accepted as appropriate risk management rather than pathway failure. Equally, if cancellations become frequent, the eligibility criteria should be revised and continuous audit undertaken.

IMPLEMENTATION AND GOVERNANCE

Safe implementation depends on organizational readiness as much as patient selection. Surgical, anaesthetic, nursing and administrative teams should agree the pathway, minimum dataset, exclusion criteria, documentation standard and escalation route before direct listing begins. Responsibility for reviewing recent investigations and medication changes must be explicit. Patients should receive clear instructions about fasting, medicines, transport, discharge support and the possibility that surgery may be postponed if new concerns arise.

Implementation should begin as a defined quality-improvement program with a limited eligibility group and prospective monitoring. Early review should examine cancellations, unexpected anaesthetic findings, unplanned admission, postoperative complications, complaints and recurrent biliary admission while awaiting surgery. A multidisciplinary governance group should review adverse events and near misses, revise eligibility criteria when necessary and ensure that pressure to improve throughput does not override clinical judgement (Table 4).

Table 4 Suggested eligibility criteria for direct listing without routine clinic-based pre-assessment.

Criterion	Direct listing suitable when	Formal assessment required when
ASA status	ASA I-II with stable or absent comorbidity	ASA III-IV or uncertain classification
Functional capacity	Good exercise tolerance and no unexplained symptoms	Poor functional capacity, dyspnoea, chest pain, syncope
Medication	Simple medication profile, no complex anticoagulation	Warfarin/DOAC complexity, antiplatelet uncertainty, insulin complexity
Investigations	Recent blood tests reviewed and acceptable	Unexplained anaemia, renal impairment, electrolyte abnormality, suspected CBD stones
Anaesthetic history	No previous difficult airway or major anaesthetic complication	Previous difficult airway, malignant hyperthermia risk, severe postoperative complication
Frailty/social factors	Independent, adequate discharge support	Frailty, cognitive impairment, safeguarding or discharge concerns

ASA: American Society of Anesthesiologists; DOAC: Direct oral anticoagulant; CBD: Common bile duct.

CLINICAL IMPLICATIONS AND PRACTICAL RECOMMENDATIONS

Use ASA I-II status as a starting point, not a complete rule. Require a structured red-flag screen before direct listing. Retain same-day anaesthetic confirmation before surgery. Reserve formal multidisciplinary assessment for ASA III-IV patients and all patients with frailty, unstable disease or complex medication issues. Audit cancellations, anaesthetic adverse events, unplanned admissions, recurrent biliary admissions, waiting time, patient experience and costs. Introduce digital triage gradually, with clinician oversight and regular safety review.

LIMITATIONS OF THE EVIDENCE BASE AND THIS REVIEW

The principal limitation is the lack of prospective comparative evidence specifically evaluating selective vs universal clinic-based assessment before early laparoscopic cholecystectomy. Much of the supporting literature concerns routine preoperative testing, ambulatory surgery or general perioperative risk and is therefore indirect. Definitions of preoperative assessment differ between services, and organisational variation in staffing, electronic records, anaesthetic capacity and access to optimization limits transferability. Rare anaesthetic events require substantially larger cohorts than those currently available, so an absence of observed events cannot establish safety.

The illustrative Hot Gallbladder Pathway data are retrospective, derived from a single NHS trust and vulnerable to selection, classification and documentation bias. Waiting time, patient-reported experience, resource use and cost-effectiveness were not prospectively measured. This narrative review did not use protocol registration, duplicate study selection, formal risk-of-bias assessment or quantitative synthesis; relevant studies may therefore have been missed, and the weighting of evidence necessarily involved author judgement. These limitations support cautious interpretation and prospective multicentre validation rather than immediate generalization (Table 5).

Table 5 Practical recommendations and evidence of strength.

Recommendation	Suggested approach	Strength of rationale
Direct listing for selected low-risk patients	ASA I-II, no red flags, recent investigations reviewed, same-day anaesthetic confirmation	Moderate; supported by indirect evidence and service experience
Formal assessment for higher-risk patients	ASA III-IV, frailty, unstable systemic disease, complex medications or airway concerns	Strong; consistent with perioperative medicine principles
Do not rely on ASA alone	Add comorbidity, frailty, functional capacity and medication review	Strong; ASA limitations are well documented
Prospective audit	Track clinical, operational, economic and patient-reported outcomes	Essential for governance and generalisability
Digital triage with oversight	Use electronic questionnaires and EPR integration; retain clinician review	Emerging; promising but requires validation

ASA: American Society of Anesthesiologists; EPR: Enterprise resource planning.

RESEARCH PRIORITIES

Prospective multicentre studies should compare selective and universal assessment using agreed eligibility criteria and standardized endpoints. Core outcomes should include day-of-surgery cancellation, anaesthetic and surgical complications, unplanned admission, critical-care use, time to surgery, recurrent biliary admission, patient-reported experience, staff workload, investigation use and total pathway cost. Studies should be powered or linked to larger datasets to examine uncommon adverse events. Digital questionnaires and prediction tools require external validation, assessment of missing data and bias, transparent clinician override and evaluation within real clinical workflows. A pragmatic cluster-randomized or stepped-wedge design may be suitable where individual randomization is difficult.

CONCLUSION

Formal preoperative assessment remains essential when patients require investigation, optimization or complex perioperative planning. Current guidance supports individualized testing and evaluation, but it does not establish that every low-risk patient benefits from a separate clinic-based appointment before early laparoscopic cholecystectomy. The available evidence suggests that selective clinic attendance may be feasible for carefully screened patients when recent clinical information is available, same-day anaesthetic authority is retained and escalation is straightforward. The 511-patient United Kingdom service evaluation provides a reassuring feasibility signal but cannot establish equivalence, rare-event safety or economic benefit. Selective assessment should therefore be introduced only as a governed, auditable service model. Prospective multicentre comparative studies are required before it can be recommended as standard practice.