Adjunctive Surgery Research Articles

Doughnut vertebroplasty for circumferential aggressive vertebral hemangiomas

BackgroundTo assess the feasibility, safety and efficacy of a percutaneous doughnut vertebroplasty of circumferential aggressive vertebral hemangiomas (VHs).MethodsWe retrospectively reviewed our prospectively collected database of patients with VHs treated with...

Adjunctive surgery after total arch distalization to optimize esthetics

This case report presents surgically assisted orthodontic treatment for an adult patient due to labial exostosis, prominent malar, and unesthetic chin. Her treatment was total arch distalization with modified C-palatal plate for maxillary arch and miniscrews for mandibular arch. In addition, she was treated with alveoloplasty, malarplasty, and genioplasty to improve the consistency of her profile. The total treatment duration was 28 months.

The Role of Advanced Endoscopic Resection of Diverse Skull Base Malignancies: Technological Analysis during an 8-Year Single Institutional Experience.

Background Resection of skull base malignancies poses complex pathological and treatment-related morbidities. Recent technological advancements of endoscopic endonasal surgery (EES) offer the ability to reexamine traditional treatment paradigms with endoscopic procedures. The utility of EES was quantitatively examined in a longitudinal series with attention to morbidities and postoperative outcomes. Methods A single-center retrospective review was performed of all malignant sinonasal tumors from 2010 to 2018. Patients with purely EES were selected for analysis. Disease features, resection extent, complications, adjuvant treatment, recurrence, and survivability were assessed. Despite the mixed pathological cohort, analysis was performed to identify technical aspects of resection. Results A total of 68 patients (47.6% males and 52.4% females, average age: 60.3 years) were included. A diversity of histotypes included clival chordoma (22.1%), olfactory neuroblastoma (14.7%), squamous cell carcinoma (11.8%), and adenoid cystic carcinoma (11.8%). Gross total resection (GTR) was achieved in 83.8% of cases. Infection (4.4%) and cerebrospinal fluid leak (1.5%) were the most common postoperative complications. Total 46 patients (67.6%) underwent adjuvant treatment. The average time between surgery and initiation of adjunctive surgery was 55.7 days. Conclusion In our 8-year experience, we found that entirely endoscopic resection of mixed pathology of malignant skull base tumors is oncologically feasible and can be accomplished with high GTR rates. There may be a role for EES to reduce operative morbidity and attenuate time in between surgery and adjuvant treatment, which can be augmented through recent mixed reality platforms. Future studies are required to systematically compare the outcomes with those of open surgical approaches.

227 - Adjunctive surgery in postchemotherapy retroperitoneal lymph node dissection (PC-RPLND) - is there always an oncologic benefit?

227 - Adjunctive surgery in postchemotherapy retroperitoneal lymph node dissection (PC-RPLND) - is there always an oncologic benefit?

Efficacy of the EDP-M Scheme Plus Adjunctive Surgery in the Management of Patients with Advanced Adrenocortical Carcinoma: The Brescia Experience.

Etoposide, doxorubicin and cisplatin plus oral mitotane (EDP-M) comprise the reference regimen in the management of patients with adrenocortical carcinoma (ACC). In this paper, we described the outcome of 58 patients with advanced/metastatic ACC consecutively treated with EDP-M in a reference center for this rare disease in Italy. In this series, EDP-M obtained a partial response in 50% of patients; median progression free survival (PFS) and overall survival were 10.1 months (95% Confidence Interval [CI 95%] 8.1–12.8) and 18.7 months (95% CI: 14.6–22.8), respectively. EDP-M was not interrupted in five patients showing disease progression after two cycles without the appearance of new lesions and mitotane levels below the therapeutic range. In two of them, the disease remained stable at further imaging evaluations and the other three obtained a partial response. Twenty-six responding patients underwent surgery of residual disease and 13 of them became disease free. Surgery identified a pathological complete response (pCR) in four patients (7%) and Ki67 expression in post-chemotherapy tumor specimens, inferior to 15% (median value), was associated with better PFS and survival. In the present study, the EDP-M regimen is confirmed to have a limited efficacy. Early disease progression does not mean treatment inefficacy. Surgery of residual disease in partially responding patients allows for the detection of pCR in few of them and this condition is predictive of long-term survival. Ki67 expression of post-chemotherapy residual disease could be an additional prognostic factor that deserves to be studied further.

Evaluation of the oncologic benefit of adjunctive surgery at time of postchemotherapy retroperitoneal lymph node dissection (PC-RPLND).

388 Background: PC-RPLND for advanced nonseminomatous germ cell tumors aims to resect all remaining metastatic tissue. The resection of adjacent visceral or vascular organs is commonly performed to achieving complete resection of the residual masses. However, the frequency of metastatic involvement of those organs with teratoma or vital cancer is currently unknown. Methods: We reviewed a cohort of 1181 patients who underwent PC-RPLND between 2008 and 2018 as a 2-center study and identified 235 (20%) cases of adjunctive surgery during PC-RPLND. We analysed the pathohistological presence of germ cell tumor elements in the resected organs: viable tumor (V), teratoma (T) or necrosis / fibrosis (N). Surgery associated complications were reported according to the Clavien-Dindo classification. Outcomes of subgroups were compared by using log-rank test. Results: V, T, N was present in 51 (21%), 91 (39%) and 93 (40%) of all patients with adjunct resected organs. In 235 patients, 316 adjunct organs were resected with 64 (27%) of these patients receiving a resection of multiple organs. The kidney was the most often resected organ (n = 74; V: 27% T: 39% N: 34%), followed by V. Cava (n = 66; V: 24% T: 36%, N: 40%) and partial liver resections (n = 48; V: 15%, T: 31%, N: 54%). Intraoperative complications occurred in 21% of patients (VT 32% vs N 17%, p = 0.021). Postoperative complications occurred in 35% of which 22% were Clavien Grad III-V showing no significant differences between VTN p = 0.093. 27% of all patients suffered from a relapse during a median follow-up of 22 months [0-180]. Patients with T or V in the resected specimens had a significantly reduced 5-year RFS compared to patients with only N (39%, 81%, p < 0.001). Conclusions: This study shows for the first time that 40% of all resections of adjunct organs are oncologically unnecessary due to the presence of N only in the pathological specimens. In case of doubt we propose an organ safe procedure with multiple intraoperative frozen section to avoiding oncologically unnecessary adjunctive surgeries especially nephrectomies and vascular resections. Additionally, a more accurate presurgical workup is required to spare patients with N from PC-RPLND.

Validating the surgical indication value of the LTB-S classification system for drug resistant tuberculosis

BackgroundCurrently there is no guideline based on preoperative clinical parameters for assessing the prognosis of the adjunctive surgery for drug-resistant tuberculosis. MethodsWe retrospectively analyzed 138 patients who had undergone surgical resection as a treatment for drug- resistant tuberculosis after 24 months. Four clinical parameters on lesion type, treatment history, body physiological status, and surgery approach were evaluated. Categorical preoperative clinical parameters were analyzed by ordinal logistic regression model when considering postoperative complications as outcomes ordered in terms of severity. Statistically significant parameters were then combined in a single classification system for predicting the outcomes of the adjunctive surgery. FindingsDiffused, progressive bilateral lesions, or active/progressive extra pulmonary tuberculosis (L3), and history of less than 2 months treatment before surgery (T3) were the strongest predicative parameters for postoperative complications and for surgery failure. Classification systems based on the four parameters were found to have a statistically significant effect on postoperative complications and postoperative efficacy. 24- month follow up indicated a high cure rate (above 95.5%) among patients without T3, L3, or severe physiological complications (B3). InterpretationA classification system based on objective clinical parameters showed predicative value for the prognosis of the adjunctive surgery and could guide management of drug-resistant Tuberculosis.

Spinal tuberculosis - Treatment options beyond guidelines

Spinal tuberculosis, a presentation of extrapulmonary tuberculosis, usually presents with chronic back pain or deformity. The diagnosis is often delayed due to the insidious and nonspecific nature of the initial symptoms. The thoracic spine is more commonly affected, but it can affect other segments or be multisegmental. The site and extent of the lesion will determine the resulting neurological deficits which can lead to significant morbidity and functional impairment. Combination chemotherapy for 6 months is recommended, but some experts may recommend therapy for 9 to 12 months depending on the circumstances. Adjunct corticotherapy and surgery are also options in specific cases. Further studies will be needed in order to better understand the role of these therapies in severe tuberculosis, and in particular spinal tuberculosis.

Laparoscopic Resection of Residual Retroperitoneal Tumor Mass in Advanced Nonseminomatous Testicular Germ Cell Tumors; a Feasible and Safe Oncological Procedure

Ten-year oncological experience of the University Medical Center Groningen with conventional laparotomy (C-RRRTM) and laparoscopy (L-RRRTM) is described concerning resection of residual retroperitoneal tumor masses (RRTM) in a large series of patients with advanced nonseminomatous testicular germ cell tumors (NSTGCT). 150 consecutive patients with disseminated NSTGCT required adjunctive surgery after combination chemotherapy. L-RRRTM was scheduled in 89 and C-RRRTM in 61 patients. Median residual tumor diameter was 20 mm in the L-RRRTM versus 42 mm in the C-RRRTM group (p < 0.001). Conversion rate was 15% in the L-RRRTM group. Perioperative complications occurred in 5 patients (6%) in the L-RRRTM and 7 (12%, NS) in the C-RRRTM group. Median duration of L-RRRTM was 156 minutes vs. 221 minutes for C-RRRTM (p < 0.001). 17/89 patients in the L-RRRTM group had postoperative complications versus 18/61 patients in the C-RRRTM group (NS). Median postoperative stay in the L-RRRTM group was 2 vs. 6 days in the C-RRRTM group (p < 0.001). During a median follow-up of 79 months, 27 patients had recurrences: 8 (9%) in the L-RRRTM group and 19 (31%) in the C-RRRTM group (p < 0.001). Laparoscopic resection of RRTM for advanced NSTGCT is feasible and an oncologically safe option in appropriately selected patients.

Clinical and Radiographic Evaluation of Multilevel Lateral Lumbar Interbody Fusion in Adult Degenerative Scoliosis.

Retrospective review of prospective data. The objective of this study was to describe the clinical, radiographic, and complication-related outcomes through ≥1-year of 27 patients who underwent lateral lumbar interbody fusion (LLIF) with posterior instrumentation to treat ≥3 contiguous levels of degenerative lumbar scoliosis. Multilevel disease has traditionally been treated with open posterior fusion. Literature on multilevel LLIF is limited. We present our experience with utilizing LLIF to treat multilevel degenerative scoliosis. Clinical outcomes were evaluated using VAS, SF-12, and ODI. Radiographic outcomes included pelvic tilt, pelvic incidence, lumbar lordosis, pelvic incidence-lumbar lordosis mismatch, Cobb angle, and cage subsidence. Perioperative and long-term complications through the ≥1-year final-postoperative visit were reviewed; transient neurological disturbances were assessed independently. Demographic, comorbidity, operative, and recovery variables, including opioid use, were explored for association with primary outcomes. Mean time to final-postoperative visit was 22.5 months; levels treated with LLIF per patient, 3.7; age, 66 years; and lateral operative time, 203 minutes. EBL was ≤100 mL in 74% of cases. Clinical outcomes remained significantly improved at ≥1-year. Cobb angle was corrected from 21.1 to 7.9 degrees (P<0.001), lordosis from 47.3 to 52.6 degrees (P<0.001), and mismatch from 11.4 to 6.4 degrees (P=0.003). High-grade subsidence occurred in 3 patients. Subsidence did not significantly impact primary outcomes. In total, 11.1% returned to the operating room for complication-related intervention over nearly 2-years; 37% experienced complications. Experiencing a complication was associated with having an open-posterior portion (P=0.048), but not with number of LLIF levels treated, or with clinical or radiographic outcomes. No patients experienced protracted neurological deficits; psoas weakness was associated with increased lateral operative time (P=0.049) and decreased surgeon experience (P=0.028). Patients who underwent multilevel LLIF with adjunctive posterior surgery had significant clinical and radiographic improvements. Complication rates were similar compared to literature on single-level LLIF. LLIF is a viable treatment for multilevel degenerative scoliosis.

Does NF2 status impact the results of combined surgery and adjunctive Gamma Knife surgery for large vestibular schwannomas?

In order to verify whether neurofibromatosis type 2 (NF2) could influence the oncological and functional outcome in large vestibular schwannoma (VS) surgery, we compared a group of NF2 patients operated with a facial nerve-sparing technique to a group of sporadic VSs of similar volume that underwent the same treatment regimen in the same period. Single-center retrospective cohort study about 12 consecutive NF2 and 69 non-NF2 patients operated on for large VS between September 2006 and November 2016. After resection, patients were allocated to an upfront Gamma Knife surgery policy of the tumor residue. At last follow-up examination, the facial nerve function was good (House-Brackmann grades I or II) in 92% of the NF2 and 83% of the non-NF2 patients (p = .90). The median volume of tumor residue was .92cc in the NF2 group and .54cc in the non-NF2 group (p = .14). Tumor control was achieved in 83% and 81% of cases in the NF2 and the non-NF2 populations, respectively, with a mean follow-up of 73months in both groups. The 1-, 5-, and 7-year progression-free survival were 92%, 83%, and 83% respectively in the NF2 group, and 99%, 83%, and 80% in the non-NF2 group (p = .96). Our analysis of 12 NF2 and 69 non-NF2 patients operated on by the same surgical team with the same treatment regimen did not show any functional or tumor control difference between those groups.

S12-04 SESSION 12: FACIOCRANIOSYNOSTOSIS – PART II INFLUENCE OF MONOBLOC/LEFORT III DISTRACTION ON THE DEVELOPING POSTERIOR MAXILLARY DENTITION AND ITS RESULTANT EFFECT ON ORTHOGNATHIC SURGERY.

Introduction: Patients with syndromic craniosynostosis often undergo midface advancements with distraction, such as a Lefort III or Monobloc, while posterior maxillary dental formation is ongoing which may indirectly damage developing tooth buds. The purpose of this study is to evaluate the dental development of the posterior maxilla after monobloc or lefort III and its clinical implications on orthognathic surgery. Methods: We evaluated the medical records and imaging (CT +/- Panorex) of all syndromic craniosynostosis patients treated at our institution from 1999–2018. Those patients without at least 1 year follow-up, incomplete medical records, or incomplete imaging were excluded from the study. Those patients who also underwent orthognathic surgery between 2014–2018 were also reviewed. Statistical comparisons of demographic, procedural, dental status and imaging data were performed. Results: 90 patients underwent midface advancement during the study period and 32 met the inclusion criteria. Average age of surgery was 7.2years. 65% (21/32) had radiographic evidence of posterior maxillary dental pathology. Increased age at time of surgery was significantly correlated with a decreased risk of dental injury (p=0.034, OR=0.55) (see attached graph). Damage to either second or third maxillary molar was significantly associated with a younger age at time of surgery (p=0.021 and p=0.034), and surgery at age seven and above trended towards being protective of the posterior maxillary dentition (Fischer exact p=0.074). There was no significant age relationship with time of surgery and injury to the first molar (p=0.173). 5 patients, average age of 17 years old, who had a previous monobloc/lefort III distraction underwent orthognathic surgery between 2014–2018. All needed adjunctive oral surgery procedures involving posterior maxillary teeth (extractions, dental exposure, anchorage of maxillary molars), and all have at least one quadrant with only first molar or no molar occlusion. Pre-orthognathic surgery orthodontics averaged 38.6 months. Conclusion: Monobloc and Lefort 3 distraction for syndromic craniofacial patients has obvious functional benefits. Early intervention is significantly associated with injury to the growing posterior maxillary dentition, and waiting until at least age 7 trends towards being protective. Damage to developing permanent maxillary molars may affect timing of orthodontic management and treatment planning for orthognathic surgery.

Condylectomy as the treatment for active unilateral condylar hyperplasia of the mandible and severe facial asymmetry: retrospective review over 18 years

Unilateral condylar hyperplasia (UCH) of the mandible is a disorder affecting the condyle size, resulting in facial asymmetry. This study was a retrospective review of 27 patients with UCH who underwent condylectomy between 2000 and 2017 at Yonsei University Dental Hospital. Patient demographic characteristics were summarized. UCH was divided into three subtypes: hemimandibular elongation (HE, n=15), hemimandibular hyperplasia (HH, n=4), and osteochondroma (OC, n=8). Of the 27 patients, only one with the HE type and five (18.5%) with the OC type complained of joint pain. Bone scans of all patients showed higher uptake on the UCH side. Lip and maxillary canting was prominent in the HH and HE types. Five patients (18.5%) underwent condylectomy alone, 13 (48.1%) underwent condylectomy with orthodontic treatment, and nine (33.3%) underwent adjunctive jaw surgery with orthodontic treatment. The treatment modalities varied according to the subtype. In all OC type patients, removal of the hyperplastic condyle treated the facial asymmetry. Additional post-surgical orthodontic treatment was necessary in only three cases (37.5%). All HH type patients required mandibuloplasty. All patients showed a stable occlusal outcome without relapse and an improvement in subjective symptoms, despite a decrease in mouth opening of 2.2mm. These findings might be useful in treatment planning for UCH patients.

Treatment of relapsed, residual and neglected clubfoot: adjunctive surgery.

Over the past two decades, the Ponseti ‘conservative’ (non-surgical) method of clubfoot treatment has been almost universally adopted worldwide. As a result, the need for operative treatment for clubfoot has decreased dramatically. However, even Ponseti himself routinely used surgery for certain patients: at least 90% of feet need percutaneous tenotomy, and 15% to 40% may require tibialis anterior tendon transfer. Additionally, relapses are common, sometimes necessitating further surgical intervention. Relapses are recurrent deformities in previously well corrected feet. Residual deformities may be defined as persistent deformities in incompletely corrected feet. In addition, in many parts of the developing world, neglected clubfoot is still a major challenge. Many neglected feet can be treated with Ponseti principles, particularly in younger children. However, in older children and adults, surgical approaches are more likely to be needed. Major reasons for relapsed/residual clubfoot include incomplete application of the Ponseti principles, inability to adhere to the foot abduction brace protocol, failure to recommend a complete course of bracing and inadequate follow-up. Sometimes, despite excellent treatment, and perfect adherence to the bracing protocols, there are still relapses, related to intrinsic muscle imbalance. We describe several solutions that include reinstitution of Ponseti casting and ‘á la carte’ operative treatment. As an alternative for particularly stubborn cases, application of a hexapod external fixator can be a powerful tool. In order to be a full-service clubfoot specialist, and not only a Ponseti practitioner, one must have in their toolbox the full gamut of adjunctive surgical options.Level of Evidence:V

Difference in Degrees of Satisfaction with Orthognathic Surgery and Orthodontic Treatment between Skeletal Class III and Cleft Patients.

The aim of this study was to compare the degrees of satisfaction with orthognathic surgery and orthodontic treatment between skeletal Class III and cleft patients. The samples consisted of Class III group (N = 25) and Cleft group (N = 16). The Modified Orthognathic Quality of Life Questionnaires, which had 5 domains (oral function [OF], awareness of dentofacial deformity [ADD], social relationship [SR], facial esthetics [FE], and nose/lip esthetics [NLE]), were evaluated with 5 rates (0 [very satisfactory] to 4 [very unsatisfactory]) at initial visit (T1), just before surgery (T2), 3 to 6 months after surgery (T3), and at debonding or 1 year after surgery (T4). The scores at each stage, amount of change between stages, and effect size (ES) in the 5 domains were investigated. Compared to Class III group, Cleft group exhibited lower satisfaction scores of NLE domain during all stages (all P < 0.001) and of SR domain and total domains at T4 stage (P < 0.05, P < 0.01). Cleft group showed significant improvement of satisfaction scores in FE domain during T1-T2 (P < 0.01), in SR, FE, NLE, and total domains during T2-T3 (all P < 0.01), in OF, SR, and total domains during T3-T4 (P < 0.05, P < 0.01, P < 0.01), and in all domains during T1-T4 (ADD, P < 0.05; OF, SR, and NLE, P < 0.01; FE and total, P < 0.001). Cleft group exhibited large improvement of ES only at SR and FE domains during T2-T3 (-0.81 and -1.09, respectively). Owing to lower satisfaction of NLE domain at all stages in cleft patients, clinicians should recommend adjunctive cosmetic surgery for nose and lip after completion of treatment.

Do alveolar corticotomy or piezocision affect TAD stability? A preliminary study

The aim of this study was to evaluate the occurrence of interradicular temporary anchorage devices (TAD) loss installed to anchor canine retraction performed in association to alveolar corticotomy (AC) versus piezocision (PZ) surgeries. One hundred maxillary self-drilling TAD were installed in 50 patients who needed first maxillary premolars extractions. One week later, AC or PZ surgeries were performed surrounding the canine and the extraction sites. A group without any adjunct surgery to accelerate tooth movement was used as control. TAD stability was evaluated throughout the 6 months of canine retraction. A total of 7, 8 and 9 TAD were lost in the AC, PZ and control groups, respectively. No significant difference in TAD stability among the groups was observed (p > 0.05). Despite the increased inflammatory response due to AC or PZ, TAD stability was not compromised.

Endoscopic cyclophotocoagulation (ECP) for childhood glaucoma: a large single-center cohort experience

To assess the factors associated with successful outcomes in the management of childhood glaucoma treated with endoscopic cyclophotocoagulation (ECP) as both primary and adjunctive surgery. The medical records of consecutive children with glaucoma treated by a single surgeon at a single center over a 17-year period using ECP procedures were reviewed retrospectively. Treatment failure was defined as (1) intraocular pressure (IOP) >24mm Hg at two consecutive examinations despite maximal medical treatment, (2) any additional glaucoma surgery, (3) sight-threatening complications, or (4) progression to no light perception visual acuity. Success was defined as the absence of treatment failure. A total of 107 ECP procedures on 80 eyes of 70 children were included. Glaucoma diagnoses included: following-cataract-surgery (60%), anterior segment dysgenesis (13%), primary congenital (9%), and other (19%). Most eyes (67 [84%]) had prior glaucoma surgery, and 73 (91%) were aphakic or pseudophakic at first ECP. Median follow-up was 2.2years (IQR, 1.1-3.5) after initial ECP; mean number of ECP treatments per eye was 1.3 (range, 1-3). Success for a single ECP treatment at 1, 3, and 5years (Kaplan-Meier analysis) was 64% (95% CI, 54-76), 36% (26-50), and 16% (7-37), respectively. Cumulative success (≥1 ECP) at 5years was 34% (23-50). In multivariable analysis, of many risk factors considered, only a preoperative IOP of <32mm Hg was significantly associated with treatment success. ECP represents a modestly effective long-term therapy for childhood glaucoma and may be most successful in patients with preoperative IOP of <32mm Hg.

Pulmonary function and respiratory health after successful treatment of drug-resistant tuberculosis

BackgroundPost-treatment morbidity among subjects with drug-resistant tuberculosis (DR-TB) is unclear. MethodsThis was a cross-sectional study of patients from Tbilisi, Georgia with cavitary DR-TB and an outcome of cure. Participants had a chest X-ray (CXR), St. George Respiratory Quality (SGRQ) survey, and pulmonary function tests (PFTs) performed. Correlations between SGRQ and PFT results and factors associated with pulmonary impairment were examined. ResultsAmong 58 subjects (median age 31 years), 40% used tobacco, 59% had prior TB, and 47% underwent adjunctive surgical resection. The median follow-up time was 41 months. Follow-up CXR revealed fibrosis in 30 subjects (52%) and bronchiectasis in seven (12%). The median forced expiratory volume (FEV1)/forced vital capacity (FVC) ratio was 0.72, with 24 subjects (41%) having a ratio of ≤0.70. Significant correlations existed between PFT measures and overall and component SGRQ scores. In linear regression, age, prior TB, and CXR fibrosis or bronchiectasis were significantly associated with decreased pulmonary function. Adjunctive surgery was significantly associated with a higher percent predicted FEV1 and FVC. ConclusionsA high proportion of DR-TB subjects had residual pulmonary impairment, particularly with recurrent TB and severe radiological disease. The association of surgical resection with improved lung function deserves further study. PFTs and SGRQ may both be useful to evaluate lung health.

621 - Higher frequence of adjunctive surgery after salvage chemotherapy in patients with testicular cancer

621 - Higher frequence of adjunctive surgery after salvage chemotherapy in patients with testicular cancer

In Reply to the Letter to the Editor Regarding “Adjunctive Gamma Knife Surgery or Wait and Scan Policy After Optimal Resection of Large Vestibular Schwannomas: Clinical and Radiologic Outcomes”

The use of image guidance (IG) in neurosurgery is ubiquitous, even though evidence from patient outcome data has remained limited to smaller, mostly observational, studies. Ommaya reservoir insertion (ORI) has been available as a treatment option for targeted intraventricular pharmacotherapy since the 1960s, far preceding the modern neuronavigation era. We conducted a systematic review and meta-analysis investigating the impact of IG on surgical outcome from ORI.A systematic database search of MEDLINE and EMBASE was performed to identify studies on operative outcomes from ORI. Only studies reporting patient demographics and perioperative outcomes (hemorrhage, infection, malposition, malfunction, and mortality) were included. Study quality was assessed via MINORS criteria.Of the 3560 records screened, 43 studies met study inclusion criteria, for a total of 1995 ORI procedures. Pooled rates of outcome for IG compared with non-IG were 6.4% versus 14.1% for overall complications; 2.0% compared with 2.8% for catheter malfunction; 2.3% compared with 3.3% for catheter malposition; 0.7% compared with 4.5% for early infection; and 0.6% compared with 1.4% for mortality. Postoperative hemorrhage was increased at 3.4% compared with 2.4%. Subgroup analysis revealed a difference in early infection rate between frameless and frame-based IG at 0.0% versus 1.9%. Meta-regression revealed a relationship between publication date and all operative outcomes except for catheter malposition and hemorrhage.This study offers a historical context on the evolution of the practice of ORI and comprises the largest observational analysis of operative outcomes providing objective support for the use of IG in neurosurgery.