Intrinsic predictors of prolonged length of stay in a colorectal enhanced recovery pathway: a prospective cohort study and multivariate analysis.

AIM: This was a prospective cohort study to determine the intrinsic non-modifiable factors influencing length of stay (LOS) in unselected consecutive patients undergoing elective colorectal surgery within an enhanced recovery pathway. METHODS: This study interrogated a prospective database of consecutive elective procedures from October 2006 to April 2011 at a tertiary referral academic hospital in the UK to identify independent predictors of prolonged length of stay (pLOS). pLOS was defined as longer than median length of stay (mLOS). Differences in determinants were identified in three groups of increasing operative complexity. RESULTS: In all, 872 procedures were identified and ranged from a simple ileostomy reversal to complex total pelvic exenteration. Preoperative anaemia and American Society of Anesthesiologists (ASA) Grade III+ predicted pLOS in stoma reversal surgery patients (n = 191, mLOS 4 days). In colonic and small bowel surgery (n = 444, mLOS 8 days), an open procedure, new stoma formation, planned critical care admission and ASA III+ predicted pLOS. New stoma formation and planned critical care admission predicted pLOS in patients undergoing pelvic rectal surgery (n = 237, mLOS 11 days). pLOS was associated with significantly higher morbidity across Dindo-Clavien grades and a longer time to postoperative functional recovery and discharge. CONCLUSIONS: Operative complexity is associated with longer LOS even with an established enhanced recovery pathway in place. Intrinsic non-modifiable predictors of pLOS differ with operative complexity, and this should be taken into account when planning benchmarking and research across units.

An established abdominal wall multidisciplinary team improves patient care and aids surgical decision making with complex ventral hernia patients.

INTRODUCTION: Abdominal wall reconstruction (AWR) is an emerging subspecialty within general surgery. The practice of multidisciplinary team (MDT) meetings to aid decision making and improve patient care has been demonstrated, with widespread acceptance. This study presents our initial experience of over 150 cases of complex hernia patients discussed in a newly established MDT setting. METHODS: From February 2020 to July 2022 (30-month period), abdominal wall MDTs were held bimonthly. Key stakeholders included upper and lower gastrointestinal surgeons, a gastrointestinal specialist radiologist, a plastic surgeon, a high-risk anaesthetist and two junior doctors integrated into the AWR clinical team. Meetings were held online, where patient history, past medical and surgical history, hernia characteristics and up-to-date computed tomography scans were discussed. RESULTS: Some 156 patients were discussed over 18 meetings within the above period. Ninety-five (61%) patients were recommended for surgery, and 61 (39%) patients were recommended for conservative management or referred elsewhere. Seventy-eight (82%) patients were directly waitlisted, whereas seventeen (18%) required preoperative optimisation: three (18%) for smoking cessation, eleven (65%) for weight-loss management and three (18%) for specialist diabetic assessment and management. In total, 92 (59%) patients (including operative and nonoperative management) have been discharged to primary care. DISCUSSION: A multidisciplinary forum for complex abdominal wall patients is a safe process that facilitates decision making, promotes education and improves patient care. As the AWR subspecialty evolves, our view is that the "complex hernia MDT" will become commonplace. We present our experience and share advice for others planning to establish an AWR centre.

Financial and clinical governance implications of clinical coding accuracy in neurosurgery: a multidisciplinary audit.

Clinical coding is the translation of documented clinical activities during an admission to a codified language. Healthcare Resource Groupings (HRGs) are derived from coding data and are used to calculate payment to hospitals in England, Wales and Scotland and to conduct national audit and benchmarking exercises. Coding is an error-prone process and an understanding of its accuracy within neurosurgery is critical for financial, organizational and clinical governance purposes. We undertook a multidisciplinary audit of neurosurgical clinical coding accuracy. Neurosurgeons trained in coding assessed the accuracy of 386 patient episodes. Where clinicians felt a coding error was present, the case was discussed with an experienced clinical coder. Concordance between the initial coder-only clinical coding and the final clinician-coder multidisciplinary coding was assessed. At least one coding error occurred in 71/386 patients (18.4%). There were 36 diagnosis and 93 procedure errors and in 40 cases, the initial HRG changed (10.4%). Financially, this translated to pound111 revenue-loss per patient episode and projected to pound171,452 of annual loss to the department. 85% of all coding errors were due to accumulation of coding changes that occurred only once in the whole data set. Neurosurgical clinical coding is error-prone. This is financially disadvantageous and with the coding data being the source of comparisons within and between departments, coding inaccuracies paint a distorted picture of departmental activity and subspecialism in audit and benchmarking. Clinical engagement improves accuracy and is encouraged within a clinical governance framework.

The uptake of laparoscopic colorectal surgery in Great Britain and Ireland: a questionnaire survey of consultant members of the ACPGBI.

OBJECTIVE: The National Institute for Clinical Excellence (NICE) has recommended laparoscopic resection as an alternative to open surgery for patients with colorectal cancer. The aim of this study was to evaluate the current uptake of laparoscopic colorectal surgery in Great Britain and Ireland. METHOD: A questionnaire was distributed to members of the Association of Coloproctology of Great Britain and Ireland (ACPGBI) regarding their current surgical practice. Results were analysed individually, by region, and nationwide. RESULTS: Information was received on 436 consultants (in 155 replies), of whom 233 (53%) perform laparoscopic colorectal procedures. During the previous year, 25% of colorectal resections were performed laparoscopically by the respondents. However, of those surgeons who were performing laparoscopic resections, only 30% performed more than half of all their resections laparoscopically. Right hemicolectomy, left-sided resections, and rectopexy were the most frequently performed laparoscopic resections. There was an even distribution throughout the country of consultants performing laparoscopic resections (regional IQR 48-60%). The main reason for consultants not performing laparoscopic procedures was a lack of training or funding. CONCLUSION: Laparoscopic colorectal surgery is being performed by more than half (53%) of colorectal consultants nationwide, although only a quarter of all procedures are being undertaken laparoscopically.

Cellular orientation of atrial natriuretic peptide in the human brain.

Many peptide hormones and neurotransmitters have been detected in human neuronal tissue. The localisation of atrial natriuretic peptide (ANP) in the human brain was considered to be both interesting and relevant to the understanding of neurochemistry and brain water-electrolyte homeostasis. This vasoactive peptide hormone has been localised in rat and frog neuronal tissue. In the present study, we report the immunohistochemical localisation of ANP in autopsy samples of human brain tissue employing the avidin-biotin-peroxidase complex technique, using an antibody against a 28 amino acid fragment of human ANP. The most intense staining of immunoreactive ANP was detected in the neurones of preoptic, supraoptic and paraventricular nuclei of the hypothalamus, epithelial cells of the choroid plexus and ventricular ependymal lining cells. Immunoreactive neurones were also observed in the median eminence, lamina terminalis, infundibular and ventromedial nuclei of the hypothalamus, and in neurones of the brain stem, thalamic neurones and some neurones of the caudate nucleus. The network of ANP cells in numerous hypothalamic centres may regulate the salt and water balance in the body through a hypothalamic neuro-endocrine control system. ANP in the brain may also modulate cerebral fluid homeostasis by autocrine and paracrine mechanisms.

Praziquantel (pyrazinoisoquinolone) in active cerebral cysticercosis.

A prospective open therapeutic study on volunteers with active neurocysticercosis using pyrazinoisoquinolone (Praziquantel) has shown that it is a safe and effective drug. Objective assessment of the effect of treatment was by high resolution sequential computed tomographic scanning. Sixty-six patients received the drug. Forty-one records were available for complete analysis at the end of 1 year of follow-up. The concomitant use of steroids reduced side effects significantly. A 98% improvement was achieved.

Penetrating stab wounds to the brain: the timing of angiography in patients presenting with the weapon already removed.

Angiography is always necessary in patients with penetrating stab wounds to the head, to exclude unexpected vascular lesions. The most important, since they are seldom clinically evident, are traumatic aneurysms and arteriovenous fistulae. It has previously been proposed that carotid angiography should be delayed until the start of the second week, to allow for better visualization of these complications. However, traumatic aneurysms can rupture at any time after the injury, and the mortality resulting from a second hemorrhage is unacceptably high. A prospective study was undertaken in which 330 patients with penetrating stab wounds to the head underwent angiography as soon as possible after admission. In 250 of these patients (76%), the weapon had already been removed by the assailant, and there was radiological evidence of penetration of the dura. Of these 250, 130 patients underwent angiography within 7 days of the injury. Another 51 patients, who presented late, underwent angiography more than 7 days after the injury. The timing of angiography did not affect the identification of traumatic aneurysms, the incidence of which was 12% in both groups. Of the patients with cranial stabs and who required urgent evacuation of intracerebral hematomas, 10% had traumatic aneurysms that could be dealt with simultaneously. No patient in this series suffered a secondary hemorrhage. We conclude that it is neither necessary nor safe to delay angiography. In some patients, either because of vasospasm or "cut-off" of a vessel, a second angiogram may be necessary to further elucidate a vascular abnormality that might not have been evident originally.

Cerebellar abscess: the impact of computed tomographic scanning.

Thirty-four cases of cerebellar abscess, diagnosed by computed tomographic (CT) scanning, were managed according to a standard protocol during a 4-year period. Triple high dosage intravenous antibiotics were used, open catheter drainage of the abscess was instituted, and external ventricular drainage was added if obvious hydrocephalus was present. Seventeen patients made a good recovery, and five remained minimally disabled. Ten patients died, and two were left severely disabled. A relationship between the level of consciousness on admission and final outcome was established. In addition, two particular CT scan features (viz. the presence of hydrocephalus and the stage of the abscess) were significant adverse prognostic factors.

Cerebellar abscess: the significance of cerebrospinal fluid diversion.

OBJECTIVE: Cerebellar abscesses that are often ominously silent have a significant mortality. Sudden total occlusion of cerebrospinal fluid (CSF) pathways makes an aggressive surgical approach mandatory. Our neurosurgical unit at Wentworth Hospital, Durban, South Africa, prospectively instituted a protocol for patients with cerebellar abscesses with reference to CSF diversion with the aim of improving outcome. Our 13-year experience with this approach to cerebellar abscesses is presented. METHODS: Since 1983, patients with cerebellar abscesses have been managed according to a standard protocol. In 1987, a policy of aggressive CSF diversion was prospectively instituted. This involved immediate CSF diversion in any patient with over or incipient hydrocephalus, even if fully conscious. The associated hydrocephalus was diagnosed on initial computed tomographic scans. CSF diversion was performed by means of a ventricular drain, inserted in the reception area under local anesthesia. The period from January 1983 to December 1995 was analyzed, and the impact of aggressive CSF diversion on patient outcome was evaluated. RESULTS: Seventy-seven patients with cerebellar abscesses during the 13-year period under review were studied. Thirty-four patients were treated before the introduction of the policy of aggressive CSF diversion. Of these patients, 10 died, resulting in a mortality of 29% and a morbidity of 21%. Forty-three patients were treated after the institution of the new policy of CSF diversion. Of these patients, five died, resulting in a mortality rate of 11.6% and a morbidity rate of 14%. CONCLUSION: Although surgical drainage of a cerebellar abscess and eradication of the primary septic source and appropriate antibiotic coverage are necessary, the management of hydrocephalus, or even incipient hydrocephalus, is of paramount importance.

Invasive mole presenting as a spinal extradural tumor: case report.

The most common sites of metastatic lesions that are caused by an invasive mole are lung, liver, and brain. Spinal spread is very rare. We present a 24-year-old patient with paraparesis that was caused by an extradural spinal invasive mole. Surgery, for decompression and biopsy, and subsequent chemotherapy resulted in complete recovery.

Infratentorial empyema: analysis of 22 cases.

OBJECTIVE: Infratentorial empyema is an uncommon form of intracranial suppuration that is usually secondary to neglected otogenic infection. The diagnosis is frequently delayed and often confused with that of meningitis. The associated mortality is distressingly high, yet it has, as a clinical entity, received scant attention in the literature. We present a 13-year experience of this condition. PATIENTS AND METHODS: From a retrospective analysis of 3865 patients with intracranial suppuration during a 13-year period, 22 patients with infratentorial empyema were identified. The inpatient notes for these patients were analyzed with reference to clinical, radiological, bacteriological, operative, and outcome data. RESULTS: Twenty-two patients with infratentorial empyema accounted for 0.6% of admissions caused by intracranial suppuration during the study period. Of these 22 empyemas, 13 were subdural and 9 epidural. Hydrocephalus was present in 17 (77.3%). Except for two epidural empyemas that did not warrant neurosurgical intervention, all patients underwent standard surgical management (wide posterior fossa craniectomy). Nineteen underwent mastoidectomy because the source of infection was otogenic. Concomitant and persistent hydrocephalus was treated aggressively. Five patients died (mortality rate of 22.7%). All fatalities had subdural empyemas, and all three patients with cerebellopontine angle extension of subdural purulent collections died. CONCLUSION: Although rare, infratentorial empyema, especially when subdural, is a lethal disease. Cerebellopontine angle extension of pus was a particularly ominous sign in our experience. Early surgical drainage via wide posterior fossa craniectomy, aggressive treatment of associated hydrocephalus, eradication of the primary source of sepsis, and, finally, intravenous high dosage of appropriate antibiotics form the mainstay of treatment.

Cranial extradural empyema in the era of computed tomography: a review of 82 cases.

OBJECTIVE: Intracranial suppurative disorders (abscesses and empyemas) continue to be common neurosurgical emergencies in South Africa. Cranial extradural empyema (EDE) occurs less frequently than its subdural counterpart but remains a potentially devastating disease process. We present our 15-year experience with this condition in the era of computed tomography. METHODS: Of the 4623 patients with intracranial sepsis who were admitted to the neurosurgical unit at Wentworth Hospital (Durban, South Africa) during a 15-year period (1983-1997), 76 patients with EDEs were identified. An additional six patients who were identified from our outpatient records were treated nonsurgically. Analyses were performed with respect to clinical, radiological, bacteriological, surgical, and outcome data. All information for this study was obtained from the computerized databank for the unit. Statistical analyses of the related pre- and postoperative clinical data were performed. RESULTS: The 76 patients with EDEs accounted for 1.6% of the total number of patients admitted for treatment of intracranial sepsis during the study period. Thirteen patients (15.8%) had infratentorial pus collections. Male patients predominated by a ratio of 2:1, and 66 patients were between the ages of 6 and 20 years (mean age, 16.56+/-9.87 yr). The origins of the sepsis were paranasal sinusitis for 53 patients (64.6%), mastoiditis for 16 patients, trauma for 5 patients, dental caries for 1 patient, and miscellaneous causes for 7 patients. The most common clinical presenting features were fever, neck stiffness, and periorbital edema. Surgery was performed in the form of burrholes for 21 patients, small craniectomies for 39 patients, and craniotomies for 5 patients. The additional five patients, while having drainage of their infected paranasal sinuses, had simultaneous drainage of their extradural pus collections by the ear, nose, and throat surgeon. The majority of patients (81 patients) experienced good outcomes (Glasgow Outcome Scale scores of 4 or 5). A single patient died after surgery (mortality rate, 1.22%). CONCLUSION: EDEs occur less frequently than subdural empyemas and are associated with better prognoses. Surgical drainage (burrholes), simultaneous eradication of the source of sepsis, and high-dose intravenous antibiotic therapy remain the mainstays of treatment. Selective nonsurgical management of small EDEs is possible, provided the source of sepsis is surgically eradicated. It is our opinion that EDE is a disease that should be managed without morbidity or death.

Intracranial subdural empyemas in the era of computed tomography: a review of 699 cases.

OBJECTIVE: Intracranial empyemas are the most common form of intracranial suppuration seen in our unit and, despite modern antibiotic therapy and advanced neurosurgical and imaging facilities, these pus collections remain a formidable challenge, often resulting in significant morbidity and death. We present an analysis of our 15-year experience with this condition in the era of computed tomography. METHODS: A retrospective analysis of 4623 patients admitted with intracranial sepsis during a 15-year period (1983-1997) identified 699 patients with intracranial subdural empyemas. The inpatient notes for these patients were analyzed with respect to clinical, radiological, bacteriological, surgical, and outcome data. Statistical analyses were performed. RESULTS: The 699 intracranial subdural empyemas accounted for 15% of all admissions for intracranial sepsis during the study period. Young male patients in the second or third decade of life were most commonly affected (62%), and the mean age was 14.65+/-12.2 years. Almost all patients (96%) underwent surgery. Eighty-two percent of patients experienced good outcomes (Glasgow Outcome Scale scores of 4 or 5). A morbidity rate of 25.9% (including postoperative seizures) was noted, and 85 patients died (mortality rate, 12.2%). CONCLUSION: Intracranial subdural empyema, which is a neurosurgical emergency, is rapidly fatal if not recognized early and managed promptly. Early surgical drainage, simultaneous eradication of the primary source of sepsis, and intravenous administration of high doses of appropriate antibiotic agents represent the mainstays of treatment.

Craniotomy improves outcomes for cranial subdural empyemas: computed tomography-era experience with 699 patients.

OBJECTIVE: Uncertainty regarding the best surgical management for subdural empyemas (SDEs) continues. Our unit has considered craniotomy the preferred method of surgical drainage for all cranial SDEs since 1988. We performed an analysis of our previously published, computed tomography-era, experience with 699 patients. METHODS: Two analyses of the database (1983-1997) were performed. First, analysis of the periods from 1983 to 1987 and from 1988 to 1997 was performed. Second, analysis of the composite database was performed. Outcomes were compared for possible outcome predictors by univariate analysis. Multivariate analysis was used to identify variables that contributed independently to outcomes, using stepwise discriminant analysis. RESULTS: Significant correlations between the analyzed periods with respect to outcome and type of surgery (P = 0.001) were noted. Analysis of the entire database (1983-1997) revealed a significant relationship between outcome and surgery type (P = 0.05). Pairwise comparison of limited procedures such as burr holes or craniectomies with wide-exposure surgical procedures such as primary craniotomies or procedures proceeding to full craniotomies indicated significant correlation with outcomes (P = 0.027). Reoperation and morbidity rates were increased with limited procedures. Stepwise discriminant analyses revealed that the type of surgery was correlated with outcomes (P = 0.0008, partial r(2) = 0.034). CONCLUSION: Craniotomy was determined to be the surgical procedure of choice for treatment of cranial SDEs, allowing complete evacuation of the pus and, more importantly, decompressing the underlying cerebral hemisphere. Limited procedures such as burr holes or craniectomies may be performed for patients in septic shock, for patients with parafalcine empyemas, or for children with SDEs secondary to meningitis.

Nonoperative management of extradural hematoma.

Extradural hematomas (EDHs) do not always require surgical evacuation. We report a subgroup of conscious patients harboring EDHs who were referred for computed tomographic (CT) scanning several days after head injury with neurological signs that were static or improving. Twelve patients with EDHs 12 to 38 ml in volume were offered nonsurgical management and were followed by serial CT scanning. All patients made a complete neurological recovery and showed resolution of the hematoma on CT scanning over a period of 3 to 15 weeks. The features that may make an extradural hematoma suitable for conservative treatment are discussed.

Role of cerebrospinal fluid shunting for human immunodeficiency virus-positive patients with tuberculous meningitis and hydrocephalus.

OBJECTIVE: Tuberculous meningitis (TBM) and its complications continue to have devastating neurological consequences for patients. Budgetary constraints, especially in developing countries, have made it necessary to select patients for shunting who are likely to experience good recoveries. To date, the value of cerebrospinal fluid shunting for human immunodeficiency virus (HIV)-positive patients with TBM has not been clearly established. METHODS: Thirty patients with TBM and hydrocephalus were prospectively evaluated. Coincidentally, one-half of the patients were HIV-positive. All patients underwent uniform treatment, including ventriculoperitoneal shunt placement and antituberculosis treatment. CD4 counts were measured for all patients. Outcomes were assessed at 1 month. RESULTS: No complications related to shunt insertion were noted. The HIV-positive group fared poorly (death, 66.7%; poor outcome, 64.7%), compared with the HIV-negative group (death, 26.7%; poor outcome, 30.8%). Despite cerebrospinal fluid shunting, no patient in the HIV-positive group experienced a good recovery (Glasgow Outcome Scale score of 5). This is in contrast to the six patients (40%) in the HIV-negative group who, with the same treatment, experienced good recoveries (Glasgow Outcome Scale scores of 5) at discharge (P<0.14). No patient (either HIV-positive or HIV-negative) who presented in TBM Grade 4 survived, whereas no HIV-positive patient who presented in TBM Grade 3 survived. A significant relationship was noted between CD4 counts and patient outcomes (P<0.031). CONCLUSION: In the absence of obvious clinical benefit, HIV-positive patients with TBM should undergo a trial of ventricular or lumbar cerebrospinal fluid drainage, and only those who exhibit significant neurological improvement should proceed to shunt surgery.

Hyponatremic natriuretic syndrome in tuberculous meningitis: the probable role of atrial natriuretic peptide.

Hyponatremia has been reported in up to one third of patients with intracranial disease and has frequently been associated with tuberculous meningitis, often complicated by hydrocephalus. The lowered plasma sodium levels were previously attributed to the syndrome of inappropriate secretion of antidiuretic hormone. A controlled prospective study of 24 patients with tuberculous meningitis and hydrocephalus was carried out. Analyses of serum electrolytes and cerebrospinal fluid were performed. Plasma and cerebrospinal fluid levels of atrial natriuretic peptide (ANP) and antidiuretic hormone (ADH) were measured by radioimmunoassay. Fifteen patients were found to be hyponatremic (plasma sodium < 130 mmol/L) and ANP levels of 12 to 1,488 pg/ml were present (median, 26 pg/ml). The remaining 9 patients had normal plasma sodium values between 130 and 145 mmol/L, and in these, plasma ANP values varied between 12 and 21.7 pg/ml (median, 12 pg/ml). The difference between these two groups was not statistically significant. (Control values from patients undergoing myelography were established to range between 12 and 40 pg/ml; median, 14.4 pg/ml.) ANP levels were undetectable in the cerebrospinal fluid in all. Plasma ADH levels in the hyponatremic group were between 7 and 159 pg/ml (median, 40 pg/ml). In the normonatremic group, plasma ADH levels of 25 to 250 pg/ml (median, 29 pg/ml) were obtained. (The controls ranged between 3.6 and 35 pg/ml; median, 10.4 pg/ml). In the hyponatremic group, there was a moderate negative correlation (r = -0.683) between plasma ANP and plasma sodium (P = 0.02). No correlation between plasma ADH and plasma sodium was found (r = -0.168; P = 0.62).(ABSTRACT TRUNCATED AT 250 WORDS)

Levels of catecholamine in plasma and cerebrospinal fluid in aneurysmal subarachnoid hemorrhage.

Despite intensive investigation into the cause of cerebral vasospasm (focal ischemic deficit) after subarachnoid hemorrhage, the morbidity and mortality associated with this condition remain high. Various studies have shown levels of catecholamine in plasma and cerebrospinal fluid (CSF) to be increased in subarachnoid hemorrhage, and it is possible that these vasoactive substances play an important role in the subsequent vasospasm. In an attempt to elucidate this possibility, the study presented here was undertaken to investigate the relationship between catecholamine levels in plasma and CSF and focal ischemic deficit (FID); the rupture of aneurysms on blood vessels supplying the hypothalamus as compared with the rupture of aneurysms on blood vessels supplying other areas of the brain; and the clinical outcome of the patients. Concentrations of adrenaline and noradrenaline in plasma and CSF samples obtained from 21 patients who had suffered aneurysmal subarachnoid hemorrhage were determined by a radioenzymatic technique. Significantly higher levels of adrenaline were found at the time of surgery in the CSF of patients with FID. A similar trend, though not statistically significant, was also observed for plasma. Patients with a rupture of aneurysms on blood vessels supplying the hypothalamus showed a tendency towards higher catecholamine levels in plasma and CSF. Subjects with a bad clinical outcome (i.e., those who were severely disabled or had died) had significantly higher levels of catecholamine in plasma than did those with a good clinical outcome (i.e., those with moderate or no disability). Further detailed analysis of the interrelationships showed that, within the group of patients with FID, those with rupture of aneurysms on blood vessels supplying the hypothalamus had significantly higher catecholamine levels in plasma than did those with rupture of aneurysms on other cerebral vessels. Furthermore, in the group of patients with rupture of aneurysms on blood vessels supplying the hypothalamus, those with a bad clinical outcome had significantly higher catecholamine levels in plasma than did those with a good clinical outcome. These findings lend support to the possibility that damage to the hypothalamus and subsequent elevations in catecholamine levels may be associated with FID and poor clinical outcome.

Operative sepsis in neurosurgery: a method of classifying surgical cases.

Neurosurgical operations have traditionally been classified along the lines of general surgical procedures. A prospective study, during an 18-month period, was undertaken in 2249 patients undergoing neurosurgical procedures to establish and evaluate a method of classifying surgical cases by the use of specific neurosurgical criteria. Patients were placed in one of five categories according to the level and type of contamination at the time of surgery. Infection included all abnormal wounds and was documented as deep when infection occurred beneath the galea (subgaleal pus, osteitis, abscess/empyema, ventriculomeningitis) and as superficial if only the scalp (including wound erythema) was involved. A statistically significant difference in the sepsis rate was found in the different categories (P < 0.0001). Of the 342 "dirty cases," 9.1% of patients developed further wound sepsis. Concomitant cerebrospinal fluid fistulae (44%), second operations (11.8%), and patients with penetrating injuries (9.2%) were the major factors implicated in sepsis in the "contaminated" category (9.7%). In the "clean contaminated" category, a sepsis rate of 6.8% was found. Prolonged surgery (longer than 4 hours) was also implicated in higher infection rates (13.4%). This study strongly supports the separation of patients who have foreign materials implanted (sepsis rate = 6.0%) from "clean" patients, essentially cases categorized as having no known risk factors that may affect sepsis, in whom a sepsis rate of 0.8% was found (P < 0.001). Importantly, surgery for the repair of so-called "clean" neural tube defects in neonates requires separate consideration. An infection rate of 14.8% existed in this subgroup. A uniform system of reporting wound abnormalities is also proposed.