Growth and Resorption of Chronic Subdural Hematomas: Gardner, Weir, and the Osmotic Hypothesis Revisited.

BACKGROUND: To explain why some chronic subdural hematomas (CSDHs) grow and/or resorb, a physically decreasing outer membrane (OM) surface area (SA) to CSDH volume (V) ratio has been reexplored, and a critical CSDH size inferred (OM SA ≈ V). Gardner showed that since CSDH protein exceeded cerebrospinal fluid (CSF) protein, CSF→CSDH osmosis occurred across a semipermeable inner membrane (n = 1). By contrast, Zollinger and Gross demonstrated that serum→CSDH osmosis could also occur across the OM (n = 1). Notably, Weir refuted Zollinger and Gross by finding equal CSDH and serum total protein (n = 20); however, Weir did not refute Gardner. Although all extant mechanisms, especially rehemorrhages, explain CSDH growth, only OM SA ≥ V simultaneously permits resorption. We aimed to reevaluate the osmotic hypothesis. METHODS: Paired serum and CSDH samples were measured in a prospective cohort. RESULTS: Results were consecutively obtained in 116 patients (87 men; mean age, 73 ± 13 years). Serum osmolality and CSDH osmolality were similar (285.70 ± 7.99 vs. 283.85 ± 7.52 mmol/kg, respectively; P = 0.11) and significantly correlated (r = 0.75, P < 0.0001). Serum total protein significantly exceeded CSDH total protein (66.6 ± 6.8 vs. 43.68 ± 20.24 g/L, P < 0.0001) as did serum albumin (35.62 ± 4.46 vs. 30.85 ± 8.5 g/L, P < 0.0001) and serum total globulins (31.5 ± 6 vs. 18.6 ± 11.4 g/L, P < 0.0001). Serum and CSDH proteins were not correlated (total protein: r = 0.003; albumin: r = 0.08; globulins: r = 0.21). CONCLUSIONS: Only crystalloids equilibrated. CSDH colloids were significantly decreased. CSDH dilution or colloidal flocculation is implied. CSDH dilution (by CSF→CSDH inner membrane [IM] osmosis or OM transudation/exudation) could favor CSDH growth, as would repeated OM hemorrhages. Contrariwise, isolated colloidal flocculation could favor CSDH shrinkage by OM CSDH→serum osmosis. The latter may result in OM SA ≥ V favorable for ultimate resolution. Our results refute Weir and Zollinger and Gross, but not Gardner. Osmotic gradients simultaneously exist for both CSDH growth and resorption. Each equilibrium could depend on each gradient relative to each IM/OM semipermeability.

S-100ß in chronic subdural haematoma: Prospective cohort study.

Chronic subdural haematoma (CSDH) is invariably classified as 'neurotrauma'. However, whilst a history of trauma/fall is frequent, it is usually distant, mild or even absent. Serum S-100ß > 1.38 µg/L is associated with a 100% specificity for mortality/poor outcome acutely after moderate-severe neurotrauma. Serum S-100ß > 0.10 µg/L is used to screen mild neurotrauma cases for emergent neuro-imaging. Serum S-100 in controls is 0.057 µg/L. S-100ß in serum or CSDH fluid (CSDHf) has not been studied. No normal 'subdural fluid' exists to compare CSDHf. We measured serum and CSDHf S-100ß at surgical drainage in a novel prospective single-centre cohort. Of n = 86/86 (100%, M65, age 73 ±â€¯13yrs), n = 66 (76%) reported mild trauma/fall 31 ±â€¯23 days previously. N = 54 (63%) presented with good clinical Markwalder Grade (MG: 0-1). Paired serum and CSDHf S-100ß samples were obtained in n = 45. CSDHf S-100ß (n = 80) was elevated (0.9 ±â€¯0.6 µg/L), was significantly higher than serum S-100ß (n = 51) (0.33 ±â€¯0.05 µg/L, P = 0.002), and was significantly correlated with midline-shift (r = 0.43, P = 0.005) and CSDH volume (r = 0.225, P = 0.046). CSDHf S-100ß was not significantly associated with any demographic factor, co-morbidity or outcome measure. CONCLUSIONS: Despite expectations, S-100ß was elevated in serum CSDH, but was significantly higher in CSDHf. Indeed, CSDHf S-100ß approached serum levels associated with a poor prognosis after acute-neurotrauma. However, CSDHf S-100ß did not represent a biomarker for trauma nor functional outcome. Whilst the non-traumatic source for on-going S-100ß release could not be determined, prolonged compression of an atrophic brain, subsequent CSF leakage, or 'subdural-space' meningeal disruption/proliferation, represent theoretical possibilities. Elevated S-100ß may therefore not be specific for mild-moderate-severe acute neurotrauma. Alternative non-traumatic intra-cranial mechanisms evidently also exist.

Early Postoperative Morbidity After Chronic Subdural Hematoma: Predictive Usefulness of the Physiological and Operative Severity Score for Enumeration of Mortality and Morbidity, American College of Surgeons National Surgical Quality Improvement Program, and American Society of Anesthesiologists Grade in a Prospective Cohort.

BACKGROUND: Although chronic subdural hematoma (CSDH) is generally benign, long-term survival (LTS) after CSDH is poor in a significant subgroup. This dichotomy has been compared to fractured neck of femur. However, although early postoperative mortality (within 30 days of CSDH) is well recorded with CSDH and similar to fractured neck of femur (4%-8%), scant accurate data exist regarding early postoperative morbidity (POMB). POMB, which prolongs length of stay (LOS) after major nonneurosurgery, is associated with decreased LTS. One recent CSDH study suggested a POMB standard of 10% i.e., notably less than with fractured neck of femur (45%). METHODS: POMB was recorded in a novel prospective single-center cohort after CSDH. The POSSUM (Physiological and Operative Severity Score for Enumeration of Mortality and Morbidity), American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) score, and American Society of Anesthesiologists (ASA) grade were assessed as tools for potentially predicting POMB. Receiver operating characteristic (ROC) curves were calculated. RESULTS: Early postoperative mortality (within 30 days of CSDH) occurred in 3 of 114 patients (3%). Seventy-one POMB events occurred in 54 of 114 patients (47%), with 27 of 54 (50%) having a Clavien-Dindo grade ≥2. Most POMB was neurologic (n = 47/71, 66%). Age (P = 0.01), Glasgow Coma Scale (GCS) score (P = 0.001), Markwalder grade (P = 0.01), hypertension (P = 0.047), and/or ≥1 preexistent comorbidity (P = 0.041) were predictive. LOS (P = 0.01) and discharge modified Rankin Scale score (P < 0.001) were significantly associated. Predicted and observed POMB with POSSUM were significantly disparate (χ2 = 15.23; P = 0.001): POSSUM area under ROC (AUROC = 0.611) was also nondiscriminatory. ACS-NSQIP (χ2 = 18.51; P < 0.001; AUROC = 0.629) and ASA grades (P = 0.25) were also nonpredictive. CONCLUSIONS: POMB was frequently disabling, mostly neurologic, and as frequent and diverse as with fractured neck of femur. POMB was significantly correlated with LOS and discharge modified Rankin Scale score. Surprisingly, POSSUM, ACS-NSQIP, and ASA grades were not predictive and would not aid consent. Simple parameters (age, Glasgow Coma Scale, Markwalder grade, hypertension, and/or ≥1 other comorbidity) were instead predictive. Longitudinal follow-up will determine whether POMB affects LTS. CSDH, like fractured neck of femur, is distinct.

Mathematical formulae to estimate chronic subdural haematoma volume. Flawed assumption regarding ellipsoid morphology.

Mathematical formulae are commonly used to estimate intra-cranial haematoma volume. Such formulae tacitly assume an ellipsoid geometrical morphology. Recently, the 'XYZ/2' formula has been validated and recommended for chronic subdural haematoma (CSDH) volumetric estimation. We aimed to assess the precision and accuracy of mathematical formulae specifically in estimating CSDH volume, and to determine typical CSDH 3-D morphology. Three extant formulae ('XYZ/2', 'π/6·XYZ' and '2/3S·h') were compared against computer-assisted 3D volumetric analysis as Gold standard in CTs where CSDH sufficiently contrasted with brain. Scatter-plots (n=45) indicated that, in contrast to prior reports, all formulae most commonly over-estimated CSDH volume against 3-D Gold standard ('2/3S·h': 44.4%, 'XYZ/2': 48.84% and 'π/6·XYZ': 55.6%). With all formulae, imprecision increased with increased CSDH volume: in particular, with clinically-relevant CSDH volumes (i.e. >50ml). Deviations >10% of equivalence were observed in 60% of estimates for 2/3S·h, 77.8% for 'XYZ/2' and 84.4% for 'π/6·XYZ'. The maximum error for 'XYZ/2' was 142.3% of a clinically-relevant volume. Three-D simulations revealed that only 4/45 (9%) CSDH remotely conformed to ellipsoid geometrical morphology. Most (41/45, 91%) demonstrated highly irregular morphology neither recognisable as ellipsoid, nor as any other regular/non-regular geometric solid. CONCLUSIONS: Mathematical formulae, including 'XYZ/2', most commonly proved inaccurate and imprecise when applied to CSDH. In contrast to prior studies, all most commonly over-estimated CSDH volume. Imprecision increased with CSDH volume, and was maximal with clinically-relevant CSDH volumes. Errors most commonly related to a flawed assumption regarding ellipsoid 3-D CSDH morphology. The validity of mean comparisons, or correlation analyses, used in prior studies is questioned.

Simultaneous multisystem surgery: An important capability for the civilian trauma hospital.

Head injury commonly presents in association with torso or limb injuries, especially in blunt trauma mechanisms. Stopping life-threatening thoraco-abdominal hemorrhage and preventing secondary brain injury are time critical priorities. Although simultaneous operative management by multiple teams has been common practice in the recent wars in Iraq and Afghanistan, simultaneous surgery is rare in most civilian settings. Nevertheless, situations arise whereby simultaneous craniotomy and chest or abdominal surgery is necessary to prevent mortality or reduce severe morbidity. We discuss two recent cases at our level one trauma centre, the challenges that surgeons and the operating room staff face and propose that with appropriate planning this surgical capability can be integrated into the systems of contemporary advanced trauma units.