BACKGROUND: PNS is caused by an infection in the sacrococcygeal area triggered by hair particle accumulation in skin tunnels, resulting in infection. Surgical options range from simple excision to complex flap constructions. Primary wound healing failure and recurrence rates contribute to the burden of PNS. RD2 Ver.02, a novel autologous whole-blood clot product, demonstrated safety and efficacy in treating complex cutaneous wounds and was investigated for the management of PNS.
METHODS: A Phase II open-label, pilot, single-arm prospective study was conducted from May 2021 to May 2023 (Ethics Committee approval #7952-20). Patients with PNS underwent a minimally invasive trephine procedure under local anesthesia followed by RD2 Ver.02 instillation into the cavity. Primary healing was assessed at 3, 6, and 12 months. Secondary outcomes included the collection of adverse events.
RESULTS: Overall, 51 patients participated in the study. At 3 months, 42/51 healed (82.4%), 7/51 (13.7%) were granulating but not completely healed, and 2/51 (3.9%) failed to heal. At 6 and 12 months, 46/51 (90.2%) and 42/51 (82.4%) achieved complete healing, respectively. At 6 months, two PNSs recurred after initial healing and an additional four instances of PNS recurrence observed in 12 months, so a total of recurrence in six patients (11.8%). There were five adverse events (AEs) with no severe adverse events.
CONCLUSIONS: RD2 Ver.02 is a safe and effective treatment of PNS when coupled with a minimally invasive trephine PNS procedure. Further comparative studies are needed to fully assess the role of this novel therapy for PNS.

This technique presents a workflow that designs the custom surgical guide to cover a trephine bur using simple slicer software and three-dimensional (3D) printing to perform the semilunar technique. This method in autogenous bone grafting surgery harvests a thin layer of cortical bone in the donor site with a trephine bur. Its biologically favorable, round shape can be used as a shell to reconstruct the ridge with a 3D contour acceptable for future implant placement. A 78-year-old female patient required vertical and horizontal bone grafting for future implant placement due to the infection caused by the vertically fractured root of a premolar. The patient\'s cone beam computed tomography (CBCT) file was translated into a standard tessellation language (STL) file, and recipient and donor site models were created. Simulated surgery was done using the software first to detect any possible complications during surgery. The trephine bur planned for use in surgery was measured in necessary dimensions, and the values were added to create a guide for surgery in slicer software. Then, it was 3D-printed with a stereolithography (SLA) printer. After testing the fit of the guide, it was further tested on a fused filament fabrication (FFF) printed donor site model to check if the desired shape and size of the plate were acquired after harvest. Then, the plates were used for model surgery on the recipient site model. After no issues from the previous steps, the final patient surgery was approved and completed with success. This technique utilizes the SLA printing method to create the custom surgical guide for a trephine bur without using commercially available products. Moreover, it could be tested on FFF 3D-printed anatomical models to ensure its validity. With this innovative technique, clinicians can efficiently perform a semilunar technique, facilitating the surgery and improving patient care.

OBJECTIVE: Chronic subdural hematoma (CSDH) is one of the most common pathologies in our daily practice. The standard treatment is the evacuation making a burr-hole and placement of a subdural drainage, which has shown to decrease its recurrence. However, this procedure can entail risks such as parenchymal damage, infection, or the onset of seizures, prompting the consideration of subgaleal drainage as an alternative. Our objective is to compare the use of subdural and subgaleal drainage in a cohort of patients undergoing intervention for CSDH, as well as to analyze the differences in complication rates and recurrence between the two groups.
METHODS: A retrospective analytical observational study was conducted, analyzing 152 patients diagnosed with CSDH who underwent intervention at our center from January 2020 to April 2022. Patients in whom drainage was not placed were excluded. In all patients, a burr-hole was performed and the type of drainage was chosen by the neurosurgeon.
RESULTS: Out of the 152 patients, subdural drainage was placed in 80 cases (52.63%), while subgaleal drainage was used in 72 cases (47.37%). There were no significant differences in the recurrence rate (30% in the subdural drainage group vs. 20.83% in the subgaleal drainage group; P = .134) or in the complication rate (7.5% in the subdural drainage group vs. 5.5% in the subgaleal drainage group; P = .749).
CONCLUSIONS: Subgaleal drainage shows similar clinical outcomes with a recurrence and complication rate comparable to subdural drainage, suggesting it as a safe and effective alternative to subdural drainage in the treatment of CSDH.

BACKGROUND: Chronic subdural haematoma is a common surgically treated intracranial emergency. Burr-hole drainage surgery, to evacuate chronic subdural haematoma, involves three elements: creation of a burr hole for access, irrigation of the subdural space, and insertion of a subdural drain. Although the subdural drain has been established as beneficial, the therapeutic effect of subdural irrigation has not been addressed.
METHODS: The FINISH trial was an investigator-initiated, pragmatic, multicentre, nationwide, randomised, controlled, parallel-group, non-inferiority trial in five neurosurgical units in Finland that enrolled adults aged 18 years or older with a chronic subdural haematoma requiring burr-hole drainage. Patients were randomly assigned (1:1) by computer-generated block randomisation with block sizes of four, six, or eight, stratified by site, to burr-hole drainage either with or without subdural irrigation. All patients and staff were masked to treatment assignment apart from the neurosurgeon and operating room staff. A burr hole was drilled at the site of maximum haematoma thickness in both groups, and the subdural space was either irrigated or not irrigated before inserting a subdural drain, which remained in place for 48 h. Reoperations, functional outcome, mortality, and adverse events were recorded for 6 months after surgery. The primary outcome was the reoperation rate within 6 months. The non-inferiority margin was set at 7·5%. Key secondary outcomes that were also required to conclude non-inferiority were the proportion of participants with unfavourable functional outcomes (ie, modified Rankin Scale score of 4-6, where 0 indicates no symptoms and 6 indicates death) and mortality rate at 6 months. The primary and key secondary analyses were done in both the intention-to-treat and per-protocol populations. The trial was registered with ClinicalTrials.gov (NCT04203550) and is completed.
RESULTS: From Jan 1, 2020, to Aug 17, 2022, we assessed 1644 patients for eligibility and 589 (36%) patients were randomly assigned to a treatment group and treated (294 assigned to drainage with irrigation and 295 assigned to drainage without irrigation; 165 [28%] women and 424 [72%] men). The 6-month follow-up period extended until Feb 14, 2023. In the intention-to-treat analysis, 54 (18·3%) of 295 participants required reoperation in the group assigned to receive no irrigation versus 37 (12·6%) of 294 in the group assigned to receive irrigation (difference of 6·0 percentage points, 95% CI 0·2-11·7; p=0·30; adjusted for study site). There were no significant between-group differences in the proportion of people with modified Rankin Scale score of 4-6 (37 [13·1%] of 283 in the no-irrigation group vs 36 [12·6%] of 285 in the irrigation group; p=0·89) or mortality rate (18 [6·1%] of 295 in the no-irrigation group vs 21 [7·1%] of 294 in the irrigation group; p=0·58). The findings of the primary intention-to-treat analysis were not materially altered in the per-protocol analysis. There were no significant between-group differences in the number of adverse events, and the most frequent severe adverse events were systemic infections (26 [8·8%] of 295 participants who did not receive irrigation vs 22 [7·5%] of 294 participants who received irrigation), intracranial haemorrhage (13 [4·4%] vs seven [2·4%]), and epileptic seizures (five [1·7%] vs nine [3·1%]).
CONCLUSIONS: We could not conclude non-inferiority of burr-hole drainage without irrigation. The reoperation rate was 6·0 percentage points higher after burr-hole drainage without subdural irrigation than with subdural irrigation. Considering that there were no differences in functional outcome or mortality between the groups, the trial favours the use of subdural irrigation.
BACKGROUND: State Fund for University Level Health Research (Helsinki University Hospital), Finska Läkaresällskapet, Medicinska Understödsföreningen Liv och Hälsa, and Svenska Kulturfonden.

This study examines the development of cranial surgery in the North Pontic region during the Early and Middle Bronze Age (late 4th and 3rd millennium BC according to the Eastern European chronology). 389 skulls from burials of this period were examined for evidence of surgical intervention. Twenty five such cases were identified and analysed for sex, age, temporal and spatial distribution, size and number of lesions, signs of healing, technique, motivation and complications of the surgery. The study indicates that cranial surgery was a well-developed medical practice in the North Pontic region during the period under consideration. Most of the cases are concentrated in the Dnipro steppe area, suggesting the possibility of outlining another centre of cranial surgery on the map of Europe. The predominant trepanation technique used here was scraping, although alternative methods were also practised. Treatment of traumatic injuries is considered to be one of the main reasons for cranial surgery in our sample. The percentage of individuals who underwent cranial intrusions increased significantly from 1.2% in the first half to 10.4% in the second half of the 3rd millennium BC, indicating a chronological shift in the distribution of cranial surgery. This trend is believed to be related to changes in weaponry during the Middle Bronze Age. The introduction of stone battle axes and maces as common weapons led to a significant increase in the occurrence of blunt force injuries, both depressed and penetrating. Trepanation may have been employed as an effective medical treatment for such traumas.

BACKGROUND: The pathogenesis of chronic subdural hematoma (CSDH) has not been completely understood. However, different mechanisms can result in space-occupying subdural fluid collections, one pathway can be the transformation of an original trauma-induced acute subdural hematoma (ASDH) into a CSDH.
METHODS: All patients with unilateral CSDH, requiring burr hole trephination between 2018 and 2023 were included. The population was distributed into an acute-to-chronic group (group A, n = 41) and into a conventional group (group B, n = 282). Clinical and radiographic parameters were analyzed. In analysis A, changes of parameters after trauma within group A are compared. In analysis B, parameters between the two groups before surgery were correlated.
RESULTS: In group A, volume and midline shift increased significantly during the progression from acute-to-chronic (p < 0.001, resp.). Clinical performance (modified Rankin scale, Glasgow Coma Scale) dropped significantly (p = 0.035, p < 0.001, resp.). Median time between trauma with ASDH and surgery for CSDH was 12 days. Patients treated up to the 12th day presented with larger volume of ASDH (p = 0.012). Before burr hole trephination, patients in group A presented with disturbance of consciousness (DOC) more often (p = 0.002), however less commonly with a new motor deficit (p = 0.014). Despite similar midline shift between the groups (p = 0.8), the maximal hematoma width was greater in group B (p < 0.001).
CONCLUSIONS: If ASDH transforms to CSDH, treatment may become mandatory early due to increase in volume and midline shift. Close monitoring of these patients is crucial since DOC and rapid deterioration is common in this type of SDH.

BACKGROUND: A lack of brain expansion is considered a risk factor for recurrence after evacuation of a chronic subdural hematoma (CSDH). To the best of our knowledge, no studies have reported on objective measurement of brain expansion after evacuation of a CSDH.
METHODS: We performed a retrospective analysis of prospectively collected data of patients undergoing 2 burr hole evacuation of a CSDH. We measured the depth of the brain surface from the frontal burr hole dural opening after hematoma evacuation using a specially devised measuring tool. Other predictors analyzed for recurrence of hematoma were age, gender, a history of hypertension, the use of anticoagulant and/or antiplatelet agents, Glasgow coma scale score at presentation, unilateral or bilateral hematoma, computed tomography appearance, and hematoma thickness.
RESULTS: Among 88 patients who underwent hematoma evacuation, 3 (3.4%) underwent surgery for recurrence. The significant factors associated with recurrence were the presence of bilateral hematoma (P = 0.001), hematoma width >2.3 cm (P = 0.04), gradation type of hematoma on the computed tomography scan (P = 0.03), and the depth of the brain after hematoma evacuation (P = 0.02). The brain expanded less in those with recurrence, with a mean depth of the brain of 18 ± 6 mm versus 7.27 ± 7.8 mm in those without recurrence.
CONCLUSIONS: Evacuation of a CSDH through 2 burr holes, along with copious irrigation and bed rest for 3 days, resulted in a very low recurrence rate without the use of a drain. A lack of brain expansion might be a predictor of recurrence. To the best of our knowledge, this is the first study to quantitatively measure the depth of the brain at surgery in patients undergoing surgery for CSDH.

The period begins with the work of Richard Wiseman who was associated with royalists in the English Civil War. A little later Dionis was the first to note a relationship between a disturbance of consciousness and extravasation of blood. This notion was continued and expanded by Le Dran, Pott, and Benjamin Bell, with Pott providing a pathophysiological explanation of the phenomenon. Daniel Turner commented on how confusing Galenic teaching was on the topic of consciousness. Heister further emphasized the relationship between clinical disturbance and the extravasation of blood. Le Dran stated that symptoms following cranial trauma related to cerebral injury, an opinion supported by Pott and never subsequently challenged. Latta noted the importance of meningeal arteries in the development of hematomas. Benjamin Bell considered trepanation only appropriate for a clinical deterioration consistent with hemorrhagic extravasation. The two Irish surgeons made it clear that the presence of periosteal separation was not in fact a reliable indicator of an extravasation. The most striking change of instruments was disappearance of simple straight trepans with non-perforating tips for making small holes safely. The use of scrapers gradually declined as did that of lenticulars. There was a great debate about the value of a conical rather than a cylindrical crown. The former was said to be safer. But this opinion faded and the cylindrical crown became preferred. Another improvement in technique involved the use of constant probing to check the depth of the drilled groove.

The authors of the texts described in this chapter will have had access to the anatomy of Vesalius; a marked step forward. However, there was no equivalent advance in physiology. Harvey\'s book on the circulation of the blood was published in 1628 but it took many years for its contents to be accepted as standard teaching. The century saw the development of instruments some of which look more like instruments a modern surgeon would recognize. The two major technical advances were the acceptance of a single-handed trephine and the design of crown trepans with a conical shape and blades extending up the sides. Moreover, the crown trepan had once again become the favored instrument for gaining access to the interior of the cranium. In terms of technique there was a worrying trend that surgeons could feel when they had penetrated the inner table of the skull without the need to probe. All the way back to Hippocrates, it had been customary to use probes to assess depth while trepanning. Thus, the abandonment of this safety measure if it was real, is cause for concern. However, it is not impossible that probing was continued and simply not mentioned as it was so obviously necessary as not to require comment. The lenticular illustrated remains of the triangular shape first illustrated by Vidius. It is important to note that it was not used to incise the skull but to smooth of rough edges and spicules.

This chapter is limited to the text of Della Cruce, which contains the most comprehensive account of the instruments used in cranial surgery at the time. Of particular importance is Della Cruce\'s attitude to what he called non-perforating straight trepans, which in general he disliked. It may be noted that his text was the last to describe this sort of instrument. In the succeeding centuries, changes to penetrating instruments were all variations on the shape of different kinds of crown trepan. Like Berengario, Della Cruce described brace and bit trepans with interchangeable bits. Various methods were employed to prevent them penetrating too deeply.