Foreign body reaction to hemostatic materials mimicking recurrent brain tumor. Report of three cases

Raney clip left behind the titanium mesh after cranial surgery: Case report

RATIONALE

Raney clips are commonly used in neurosurgical procedures to hold the scalp in place and stop bleeding during surgery. The removal of Raney clips is often the last process during cranial surgery prior to the closure of skin incision. Thus, a Raney clip found underneath the titanium mesh resulting in fever is a very rare occurrence.

PATIENT CONCERNS

An 18-year-old male patient underwent cranial surgery due to intracranial abscess in the frontal lobe and subsequently underwent frontal skull repair using titanium mesh during which a Raney clip was unintentional left underneath the titanium mesh resulting in fever.

DIAGNOSIS

A thin-slice computed tomography (CT) scan was used to identify the Raney clip.

INTERVENTION

A third surgery was performed to remove the Raney clip.

OUTCOMES

The patient fever total resolved after the third surgery with no further neurological deficits and 2-years follow-up revealed the patient is well and go about his daily activities.

LESSONS

It is crucial to ensure that all foreign objects are removed after the surgery by counting all instruments used at and after each step during the operation, including all Raney clips. This will help prevent complications and ensure the safety as well as the well-being of the patient.

A contemporary systematic review of the complications associated with SURGICEL

BACKGROUND

This review aims to summarize the findings from recent literature (2010-2022) reporting on complications that resulted from the surgical use of SURGICEL for intraoperative hemostasis.

METHODS

A literature search was conducted using the MEDLINE (OVID), Embase, and Cochrane Central Register of Controlled Trials - CENTRAL (OVID) databases. The studies were sorted into case reports and other study types for data extraction. Covidence was used for data extraction and statistics were descriptive.

RESULTS

Of the total 560 articles screened, 73 papers were selected for a full-text review and 70 studies were included in this review. A total of 7,242 participants were included in the studies (case studies n = 93, others n = 7149). 67/70 of the included studies reported complications when SURGICEL was used intraoperatively. Reported complications included: SURGICEL induced masses (granulomas, abscesses, hematomas, cysts) (n = 25), hemorrhagic complications (n = 12), masses misdiagnosed as tumors, cardiovascular, nervous system, and hepatobiliary complications, pain, and infections. Other complications included: fistulas, erectile dysfunction, chorioamnionitis, swelling, urinary leak, renal failure, and anaphylaxis.

CONCLUSIONS

Publications reporting on complications associated with the use of SURGICEL intraoperatively have continued to emerge. Future studies should compare how the types and rates of complications compare between SURGICEL and alternative hemostatic agents.

An autologous blood-derived patch as a hemostatic agent: evidence from thromboelastography experiments and a porcine liver punch biopsy model

Perioperative bleeding is a common complication in surgeries that increases morbidity, risk of mortality, and leads to increased socioeconomic costs. In this study we investigated a blood-derived autologous combined leukocyte, platelet, and fibrin patch as a new means of activating coagulation and maintaining hemostasis in a surgical setting. We evaluated the effects of an extract derived from the patch on the clotting of human blood in vitro, using thromboelastography (TEG). The autologous blood-derived patch activated hemostasis, seen as a reduced mean activation time compared to both non-activated controls, kaolin-activated samples, and fibrinogen/thrombin-patch-activated samples. The accelerated clotting was reproducible and did not compromise the quality or stability of the resulting blood clot. We also evaluated the patch in vivo in a porcine liver punch biopsy model. In this surgical model we saw 100% effective hemostasis and a significant reduction of the time-to-hemostasis, when compared to controls. These results were comparable to the hemostatic properties of a commercially available, xenogeneic fibrinogen/thrombin patch. Our findings suggest clinical potential for the autologous blood-derived patch as a hemostatic agent.

FDG PET/CT Features of Polysaccharide-Based Hemostatic Agent: Chronic Inflammatory Changes Can Mimic Metastatic Lesions

PURPOSE

To prevent hemorrhagic complications, hemostatic agents (HAs) have been widely used in recent years. The use of HAs can lead to false-positive results on postoperative imaging. There exists only 1 study in the literature evaluating these applications during surgical procedures. Therefore, we aimed to evaluate the postoperative imaging features of polysaccharide-based HAs in thoracic surgery patients who have had 18F-FDG PET/CT scans.

PATIENTS AND METHODS

Two hundred nine consecutive patients who underwent thoracic surgery were enrolled in this study. A topical polysaccharide-based HA was applied to the surgical bed for all of the patients. The patients diagnosed with cancer were followed up with subsequent thoracic CT scans, and 42 of these patients were also imaged with 18F-FDG PET/CT, which then comprised the main study group. Due to suspicion of metastasis, 19/42 patients were reoperated or rebiopsied. The latest histopathological findings were accepted as criterion standard, and previous FDG PET/CT images were retrospectively reevaluated.

RESULTS

Polysaccharide-based HAs that appear as amorphous basophilic material were identified in histopathological samples of 11/19 patients. Lymphocytes, plasma cells, and histiocytes, which formed foreign body reaction and/or foreign body granuloma, indicating the presence of chronic inflammation, were seen in all of the samples. 18F-FDG PET/CT showed increased FDG uptake in all of these lesions.

CONCLUSIONS

Despite the inconsistency of the literature, polysaccharide-based HAs can be demonstrated in human surgical specimens as amorphous basophilic materials even after a long time from the initial surgical procedure. These agents almost always cause chronic inflammatory changes. In addition, these agents may mimic "false-positive" findings on postoperative FDG PET/CT scans.

PLGA Nanoparticle Rapamycin- or Necrostatin-1-Coated Sutures Inhibit Inflammatory Reactions after Arterial Closure in Rats

Background: The inflammatory reaction of sutures and oozing after arterial closure depends on the suture material and the amount of oozing surrounding the sutures. Anti-inflammation coatings have been proven to be an effective strategy to decrease this reaction. The aim of this study was to establish an arterial closure oozing model in rats and to test the effect of poly (lactic-co-glycolic acid) (PLGA) nanoparticle (NP) rapamycin- or necrostatin-1(NEC-1)-coated sutures on the inflammatory reaction after arterial closure. Methods and Materials: A 10 mm arteriotomy was carried out on the carotid artery of Sprague-Dawley rats and closed using 11-0 sutures. PLGA NP-rapamycin and NEC-1 were made. The 11/0 nylon sutures were coated with PLGA NP-rapamycin and NEC-1. Sutures were examined by scanning electron microscopy, hemolysis test, and cumulative release. The carotid arteriotomy was closed using uncoated PLGA NP-rapamycin- and NP-NEC-1-coated sutures. The carotid artery was harvested on day 7. Tissues were examined by histology and immunohistochemistry. Results: There were severe inflammatory reactions in the oozing arteries compared to the normal healing arteries (P = 0.0192). PLGA NP-rapamycin- and NEC -1-coated sutures reduced foreign body reaction compared to the uncoated sutures. There were significantly smaller number of CD3 (P = 0.0068), CD45 (P = 0.0300), and CD68 (P = 0.0011) cells in the PLGA NP-rapamycin- and NP-NEC-1-coated groups compared to the uncoated group. There was a smaller number of p-mTOR (P = 0.0198)-positive cells in the PLGA NP-rapamycin-coated group compared to the uncoated group. There was a smaller number of TNFα (P = 0.0198)-positive cells in the PLGA NP-NEC-1-coated group compared to the uncoated group. Conclusions: In this rat carotid artery oozing model, PLGA NP-rapamycin- or NP-NEC-1-coated sutures can inhibit inflammatory reaction and foreign body reaction. Although this was a small rodent animal experiment, this coated suture may have a potential clinical application in the future.

Multimodality imaging of Surgicel®, an important mimic of post-operative complication in the thorax

Absorbable hemostatic agents such as Surgicel are hemostatic materials composed of an oxidized cellulose polymer used to control post-surgical bleeding and cause coagulation. This material is sometimes purposefully left in situ where it slowly degrades over time and can produce an imaging appearance that mimics serious post-operative complications such as gangrenous infections and anastomotic leaks as well as potentially mimicking disease recurrence in later stages. In this article, we review the multimodality imaging appearance of this material in situ longitudinally in the range of post-operative settings, in order to promote awareness of this entity when interpreting post-operative imaging. We present this as a pictorial review focusing primarily but not exclusively on the chest noting that the thoracic imaging appearance of Surgicel^® is less well reported in the published literature. An understanding of this entity may help to minimize erroneous diagnosis of a postoperative complication leading to unnecessary interventions.

Variants of Oxidized Regenerated Cellulose and Their Distinct Effects on Neuronal Tissue

Based on oxidized regenerated cellulose (ORC), several hemostyptic materials, such as Tabotamp^®, Equicel^® and Equitamp^®, have been developed to approach challenging hemostasis in neurosurgery. The present study compares ORC that differ in terms of compositions and properties, regarding their structure, solubility, pH values and effects on neuronal tissue. Cytotoxicity was detected via DNA-binding fluorescence dye in Schwann cells, astrocytes, and neuronal cells. Additionally, organotypic hippocampal slice cultures (OHSC) were analyzed, using propidium iodide, hematoxylin-eosin, and isolectin B₄ staining to investigate the cellular damage, cytoarchitecture, and microglia activation. Whereas Equicel^® led to a neutral pH, Tabotamp^® (pH 2.8) and Equitamp^® (pH 4.8) caused a significant reduction of pH (p < 0.001). Equicel^® and Tabotamp^® increased cytotoxicity significantly in several cell lines (p < 0.01). On OHSC, Tabotamp^® and Equicel^® led to a stronger and deeper damage to the neuronal tissue than Equitamp^® or gauze (p < 0.01). Equicel^® increased strongly the number of microglia cells after 24 h (p < 0.001). Microglia cells were not detectable after Tabotamp^® treatment, presumably due to an artifact caused by strong pH reduction. In summary, our data imply the use of Equicel^®, Tabotamp^® or Equitamp^® for specific applications in distinct clinical settings depending on their localization or tissue properties.

Photoacoustic imaging as a highly efficient and precise imaging strategy for the evaluation of brain diseases

Photoacoustic imaging (PAI) is an emerging imaging strategy with a unique combination of rich optical contrasts, high ultrasound spatial resolution, and deep penetration depth without ionizing radiation. Taking advantage of the features mentioned above, PAI has been widely applied to preclinical studies in diverse fields, such as vascular biology, cardiology, neurology, ophthalmology, dermatology, gastroenterology, and oncology. Among various biomedical applications, photoacoustic brain imaging has great importance due to the brain's complex anatomy and the variability of brain disease. In this review, we aimed to introduce a novel and effective imaging modality for diagnosing brain diseases. Firstly, a brief overview of two major types of PAI system was provided. Then, PAI's major preclinical applications in brain diseases were introduced, including early diagnosis of brain tumors, subtle changes in the chemotherapy response, epileptic activity and brain injury, foreign body, and brain plaque. Finally, a perspective of the remaining challenges of PAI was given for future advancements.

Intracranial Foreign Body Granuloma Mimicking Brain Tumor Recurrence: A Case Series

BACKGROUND

Intracranial foreign body granuloma (FBG) is a rare inflammatory reaction to retained foreign material, manifesting acutely or months to years following neurosurgical procedures. Radiographically, FBG can mimic tumor progression, and tissue biopsy may be required to guide management.

MATERIALS AND METHODS

In this retrospective case series, we present unique clinico-radiographic and histopathological features of six neuro-oncological patients diagnosed with FBG between 2007 and 2019.

RESULTS

All six patients (4 women and 2 men, aged 29-54 [median, 30.5] years) had undergone surgical resection of a low- (n = 4) or high-grade (n = 2) glioma. FBG manifestation postsurgery ranged from 1 day to 4 years and was predominantly asymptomatic (n = 5/6). Magnetic resonance imaging universally demonstrated one or multiple peripherally enhancing lesion(s) adjacent to the resection cavity. Histopathology in all (n = 4/4) resected specimens demonstrated an inflammatory reaction to foreign material, confirming FBG.

CONCLUSION

Intracranial FBG constitutes a rare but challenging treatment-related condition effectively managed by surgery, with important therapeutic implications in neuro-oncology.

Surgicel mimicking recurrent pelvic neuroblastoma in a 3-year-old boy

INTRODUCTION

Surgicel is a hemostatic agent that consists of oxidized regenerated cellulose and used in surgical procedures as an aid to bleeding control. It is left in the operation site for hemostasis, could cause an operation by mimicking the recurrence of tumor, as in our patient.

PATIENTS AND METHODS

A 3-year-old boy was operated by us at the age of 40 days and 2.5 years, respectively, due to pelvic neuroblastoma. He was re-operated for mimicking recurrence or residue tumor secondary to the prior placement of Surgicel within the peritoneal cavity.

RESULTS

Re-laparotomy was performed and the mass approximately 2.8 × 2×1 cm in size in front of the right ureter and iliac vessels and behind the bladder was removed by blunt and sharp dissection without damaging these organs. While gelatinous content was evacuated from this mass, there was no apparent tumor appearance. Pathology report was reported as fibrotic tissue characterized by foreign body and foreign body giant cells. The postoperative period was uneventful and he was discharged on the 2nd postoperative day.

CONCLUSIONS

In the light of our case, the use of hemostatic agents should be kept to a minimum and should not be left in the body unless it is difficult. Thus, unnecessary examination or recurrent surgery can be avoided.

Radiological pseudoprogression post-radiotherapy in a child with pineal germ cell tumour

Little is known about pseudoprogression in brain tumours other than gliomas. A 9-year-old male child with a pineal teratoma/germinoma underwent surgical resection followed by adjuvant chemo-radiotherapy. The magnetic resonance imaging scan 4 months post-radiotherapy showed a contrast-enhancing lesion within the surgical cavity suspicious of recurrence. These radiological findings subsequently resolved without any specific intervention. The child continues in remission 2 years post-treatment. This case illustrates the occurrence of pseudoprogression post-radiotherapy in intracranial GCT and highlights an unmet need for greater implementation of functional imaging techniques in paediatric neuro-oncology to avoid undue discontinuation of effective treatments or inappropriate enrolment in clinical trials.

Postoperative Textiloma Mimicking Intracranial Rebleeding in a Patient with Spontaneous Hemorrhage: Case Report and Review of the Literature

During craniotomy, hemostatic materials such as oxidized cellulose and cotton pads, commonly used to control bleeding, may cause a granulomatous reaction that may produce space-occupying mass lesions termed textiloma (or gossypiboma). We present a 46-year-old female who underwent a right frontotemporal craniotomy and surgical removal of intraparenchymal cerebral hemorrhage, and who developed a textiloma during the postoperative period causing seizures. Granulomatous reactions due to hemostatic agents have been reported experimentally, as well as after cranial and spinal operations. We emphasize that although it is rare, an adverse reaction such as a postoperative textiloma due to hemostatic material and subsequent granuloma formation can result in a false image of rebleeding, tumor recurrence, radiation necrosis, or postoperative abscess, depending on the particular clinical history of each patient.

Reactive gliosis mimicking tumor recurrence - a case series documenting MRI abnormalities and neuropathological correlates

Abstract. The aim of this study is to identify, in our center, all cases of foreign-body reactions to hemostatic agents or other prostheses resulting in a radiological suspicion of tumor recurrence. We interrogated our internal database to identify all such cases and systematically evaluated the MRI brain scans of patients: (i) at the time of initial tumor diagnosis, (ii) postoperatively, (iii) and at the time of suspected tumor recurrence. In addition, we reviewed each patient’s operative notes and reviewed the histology of all cases following a second surgical intervention. In total, we identified 8 patients, 7 of whom had a WHO grade II glioma at initial surgery. We did not identify any distinguishing radiological abnormalities from the initial diagnostic brain scan to the suspected recurrence, and histologically all cases were characterized by extensive gliosis; with both macrophages and reactive astrocytes present throughout. The cause of gliosis was identified as being relating to hemostatic agents in 4 cases; in the other 4 cases, the foreign-body reaction was presumed to be caused be materials used in a craniotomy or cranioplasty. This study highlights the difficulty in radiologically diagnosing a foreign-body reaction and also identifies that such a gliotic reaction may occur as a consequence of exogenous materials used in a craniotomy or cranioplasty.

Modified Arachnoid Plasty Reduces Chronic Subdural Hematoma after Unruptured Aneurysm Clipping : Technical Note

Objective

Chronic subdural hematoma (CSDH) is a rare complication of unruptured intracranial aneurysm (UIA) clipping surgery. To prevent postoperative CSDH by reducing subdural fluid collection, we applied the modified arachnoid plasty (MAP) during the UIA clipping surgery to seal the dissected arachnoid plane.

Methods

This retrospective study included 286 patients enrolled from July 2012 to May 2015. We performed arachnoid plasty in all patients, with MAP used after June 17, 2014. Patients were divided into two groups (non-MAP vs. MAP), and by using uni- and multivariate analyses, baseline characteristics, and relationships with postoperative CSDH between the two groups were analyzed. The degree of preoperative brain atrophy was estimated using the bicaudate ratio (BCR) index.

Results

Ten patients (3.5%) among 286 patients had postoperative CSDH after clipping. Nine (3.1%) were in the non-MAP group, and one (0.9%) was in the MAP group. The higher BCR index showed statistical significance with occurrence of postoperative CSDH in both uni- (p=0.018) and multivariate (p=0.012; odds ratio [OR], 8.547; 95% confidence interval [CI], 1.616–45.455) analyses. MAP was associated with a lower risk of postoperative CSDH (p=0.022; OR, 0.068; 95% CI, 0.007–0.683).

Conclusion

This study shows that the degree of preoperative brain atrophy is associated with an increased occurrence of CSDH after clipping and that MAP could help reduce the risk of postoperative CSDH after unruptured aneurysm clipping via a lateral supraorbital approach.

Gauzoma in A Scleroderma Patient Following Open Heart Surgery: A Case Report

INTRODUCTION

Gauzoma is an iatrogenic complication which occurs rarely due to surgical team negligence. Depending on the sterility of the retained tissue, it can lead to life threatening surgical complications or may remain asymptomatic for many years and be detected incidentally in imaging studies. It may be mistaken as tumors or aneurysms. Thus, high clinical suspicion is needed to diagnose them in patients with past history of operation. Reporting Case: A 35 years old woman, a known case of scleroderma underwent open-heart surgery 20 years before being diagnosed as scleroderma, presented by dyspnea especially on activity. The High Resolution CT (HRCT) for evaluating the interestial lung disease was done which detected a 7 cm (in greatest diameter) inflammatory mass in posterior aspect of left hemi thorax with a radiopaque thread in its center. True cut biopsy was done and sent for pathology, which revealed fragments of foreign body materials probably gauze pad fibers with cell debris and blood.

CONCLUSION

Here, we highlighted the details in clinical history, CT findings, and pathology report of gauzoma in thorax of a scleroderma patient following previous open-heart surgery. It can be guidance for clinician to consider this diagnosis in patients with past history of operation.

[Granulomatous inflammation in the bed of resected cerebral cavernoma in a child, caused by a hemostatic agent]

OBJECTIVE

The study presents a clinical observation of foreign body granuloma, which is rare productive inflammation, developed on treatment with a hemostatic material upon removal of cerebral cavernoma.

MATERIAL AND METHODS

A 4-year-old boy operated on for left parietal lobe cavernoma was diagnosed with a mass lesion during a follow-up MRI examination 4 months after surgery. The patient was re-operated in connection with suspected abscess formation. The pathological tissue was subjected to the histological and immunohistochemical examination.

RESULTS

Inflammation was accompanied by the formation of foreign body granulomas, and, in some areas, had immune nature with signs of focal destructive vasculitis, delayed maturation of the granulation tissue, and disturbance of the current organization and encapsulation processes. It is worth noting that granulomatous inflammation around a hemostatic material in the brain has no specific features during introscopy and mimics an abscess or tumor recurrence.

CONCLUSION

The use of hemostatic materials upon resection of cerebral cavernous malformations may cause formation of granuloma mimicking disease relapse or abscess in the long term period. To prevent granulomatous inflammation, removal of a hemostatic material, if possible, from the surgical field is recommended when reliable hemostasis is achieved.

Foamy Macrophage Deposition in Lymph Nodes Mimicking Lung Cancer Recurrence Diagnosed via Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration

The radiological finding of mediastinal lymph node enlargement following surgery for lung cancer often signifies locoregional recurrence. The use of oxidised cellulose haemostatic agents (OCHAs) during staging mediastinoscopy is common. We report a case of 18-fluorodeoxyglucose-avid subcarinal lymphadenopathy in a patient in whom OCHAs had been used at mediastinoscopy 5 months earlier. Histopathological examination of suspected nodal recurrence is facilitated by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). The technique is particularly useful after previous mediastinoscopy, when repeat surgical exploration can be challenging. EBUS-TBNA samples showed extensive foamy macrophage deposition, with no evidence of malignancy. The association between the use of OCHAs and subsequent intranodal foamy macrophage deposition is new. Clinicians should consider this possibility in the differential diagnosis of mediastinal lymphadenopathy after surgical exploration, where OCHAs have been left in situ; it remains important to resample the lymph nodes before assuming disease recurrence to prevent unnecessary treatment.

Enhancing brain lesions after endovascular treatment of aneurysms

Complications of endovascular therapy of aneurysms mainly include aneurysm rupture and thromboembolic events. The widespread use of MR imaging for follow-up of these patients revealed various nonvascular complications such as aseptic meningitis, hydrocephalus, and perianeurysmal brain edema. We present 7 patients from 5 different institutions that developed MR imaging-enhancing brain lesions after endovascular therapy of aneurysms, detected after a median time of 63 days. The number of lesions ranged from 4-46 (median of 10.5), sized 2-20 mm, and were mostly in the same vascular territory used for access. Three patients presented with symptoms attributable to these lesions. After a median follow-up of 21.5 months, the number of lesions increased in 2, was stable in 1, decreased in 3, and disappeared in 1. The imaging and clinical characteristics suggested a foreign body reaction. We could find no correlation to a specific device, but a possible source may be the generic hydrophilic coating.

Surgicel application in intracranial hemorrhage surgery contributed to giant-cell granuloma in a patient with hypertension: case report and review of the literature

BACKGROUND

Surgicel is an oxidized cellulose preparation that is widely applied in neurosurgery due to its hemostatic effect and good tissue compatibility. Tumor-like lesions induced by Surgicel application in cerebral surgery have been rarely reported, especially for intracranial hemorrhage debridement surgery in patients with hypertension.

CASE PRESENTATION

This case report describes a rare case in which Surgicel application led to a foreign body reaction, contributing to the development of an intracranial giant-cell granuloma. A 49-year-old female hypertensive patient was diagnosed with intracranial hemorrhage. She was treated with debridement surgery that employed Surgicel application. Although a satisfactory hemostatic effect was achieved, the patient was diagnosed with epilepsy 6 months later. Subsequent magnetic resonance imaging revealed an intracranial space-occupying lesion. After undergoing en bloc resection of the lesion, the patient was diagnosed with a Surgicel-related intracranial giant-cell granuloma by histopathology.

CONCLUSIONS

Application of Surgicel during intracranial hemorrhage debridement surgery may be associated with a risk of granuloma development due to formation of a tumor-like space-occupying lesion in the surgery bed. Even a low risk of tumor development implies a need for caution when applying Surgicel, especially when solely used to achieve a hemostatic effect.

Posthemispherectomy hydrocephalus: results of a comprehensive, multiinstitutional review

PURPOSE

Hemispherectomy surgery for medically intractable epilepsy is known to cause hydrocephalus in a subset of patients. Existing data regarding the incidence of, and risk factors for, developing posthemispherectomy hydrocephalus have been limited by the relatively small number of cases performed by any single center. Our goal was to better understand this phenomenon and to identify risk factors that may predispose patients to developing hydrocephalus after hemispherectomy surgery.

METHODS

Fifteen pediatric epilepsy centers participated in this study. A retrospective chart review was performed on all available patients who had hemispherectomy surgery. Data collected included surgical techniques, etiology of seizures, prior brain surgery, symptoms and signs of hydrocephalus, timing of shunt placement, and basic demographics.

KEY FINDINGS

Data were collected from 736 patients who underwent hemispherectomy surgery between 1986 and 2011. Forty-six patients had preexisting shunted hydrocephalus and were excluded from analysis, yielding 690 patients for this study. One hundred sixty-two patients (23%) required hydrocephalus treatment. The timing of hydrocephalus ranged from the immediate postoperative period to 8.5 years after surgery, with 43 patients (27%) receiving shunts >90 days after surgery. Multivariate regression analysis revealed anatomic hemispherectomies (odds ratio [OR] 4.1, p < 0.0001) and previous brain surgery (OR 1.7, p = 0.04) as independent significant risk factors for developing hydrocephalus. There was a trend toward significance for the use of hemostatic agents (OR 2.2, p = 0.07) and the involvement of basal ganglia or thalamus in the resection (OR 2.2, p = 0.08) as risk factors.

SIGNIFICANCE

Hydrocephalus is a common sequela of hemispherectomy surgery. Surgical technique and prior brain surgery influence the occurrence of posthemispherectomy hydrocephalus. A significant portion of patients develop hydrocephalus on a delayed basis, indicating the need for long-term surveillance.

Postoperative aseptic intracranial granuloma: the possible influence of fluid hemostatics

Background. Numerous reports have demonstrated how postoperative intracranial granulomas can often mimic neoplasm clinically, radiologically, and even macroscopically. Herein we present an unusual case of postsurgical intracranial aseptic granuloma secondary to a chronic inflammatory reaction without any identifiable retained foreign body. Case Description. A 71-year-old patient started complaining of severe headache seven months after surgical excision of WHO Grade I right frontal falx meningioma. CT and MRI scans disclosed a contrast-enhanced lesion with diffuse mass effect in the previous surgical site. The lesion was resected; intraoperative finding and histological specimens led to the diagnosis of postoperative granuloma, likely expression of a glial reaction to the fluid absorbable hemostatics applied in the surgical site after meningioma excision. The possible granuloma-inducing materials and the timing of granuloma formation are discussed. Conclusion. A comprehensive analysis of clinical and neuroradiological data, as well as results of blood tests including positive and negative acute phase proteins, is mandatory to raise the suspicion of postoperative granuloma. The treatment options should be evaluated on a case-by-case basis, with a conservative attitude being the one of choice only for patients without progressive neurological deficit. Alternatively, aggressive surgical treatment and histopathological examination should be advocated.

Microfibrillar collagen hemostat-induced necrotizing granulomatous inflammation developing after craniotomy: a pediatric case series

OBJECT

Microfibrillar collagen hemostat (MCH; trade name Avitene) is a partially water-insoluble acid salt of purified bovine corium collagen. This agent has been widely used to control hemorrhage at surgery, and especially during pediatric neurosurgeries at the authors' institution. Despite its effectiveness, rare case reports detailing adverse inflammatory reactions to MCH have been documented. Based primarily on MR imaging, postoperative reactions have most commonly elicited clinical differential diagnoses of tumor recurrence or abscess. According to the literature, MCH induces a very characteristic mixed inflammatory response that is rich in eosinophils; in light of these observations, many authors have suggested an allergy-based pathogenesis.

METHODS

The authors retrospectively reviewed 3 pediatric neurosurgical cases treated at their institution, wherein a common histomorphological inflammatory reaction to MCH was elicited at the site of prior craniotomy.

RESULTS

Case 1 is that of a 10-year-old girl whose diagnosis was a right temporal lobe ganglioglioma, classified as WHO Grade I. Case 2 is that of a 9-year-old boy whose diagnosis was a left parietal lobe anaplastic ependymoma, classified as WHO Grade III. Finally, Case 3 is that of a 15-year-old girl whose diagnosis was focal cortical dysplasia Type IIA affecting the left occipital lobe. Each patient presented with new or recurrent seizures 5–6 weeks after the initial resection. The postsurgical reactions incited by MCH mimicked the radiological appearance of either an abscess (Cases 2 and 3) or recurrent tumor (Case 1). Histologically, the mixed inflammatory infiltrate was typified by the presence of MCH-centric necrotizing granulomas that were surrounded by a palisade of macrophages and often several eosinophils.

CONCLUSIONS

The findings are in keeping with previous case reports describing the clinicopathological features of adverse reactions occurring due to MCH. Based on the authors' observations, the possibility of an idiopathic inflammatory reaction to MCH should be considered when either seizures, a typical radiological appearance (that is, consistent with tumor recurrence or abscess formation), or both arise shortly after initial surgery. A conservative treatment approach to this type of inflammatory lesion appears to be the most appropriate management strategy.

MR spectroscopy and perfusion MR imaging findings of intracranial foreign body granuloma: a case report

We report a case of intracranial foreign body granuloma that showed features of a high grade tumor on magnetic resonance (MR) imaging. However, the relative cerebral blood volume was not increased in the enhancing mass on perfusion MRI and the choline/creatine ratio only slightly increased on MR spectroscopy. The results suggest that the lesion is benign in nature. Perfusion MRI and MR spectroscopy may be helpful to differentiate a foreign body granuloma from a neoplastic condition.

Foreign body granulomatous change from absorbable gelatin sponge and microcoil embolization after a guidewire-induced perforation in the distal coronary artery

We report an autopsy case of treatment by absorbable gelatin sponge and microcoil embolization after perforation of the distal coronary artery by guidewire. Histological examination revealed a foreign body granuloma in the coronary artery with embolization. Foreign body reaction to absorbable gelatin sponge seemed to be stronger than that to the microcoil.

Retained surgical sponges after craniotomies: imaging appearances and complications

Imaging within 24 to 48 hours after most neurosurgical procedures is a routine practice. Nonresorbable surgical sponges have radiopaque filaments readily visible on CT scans and plain film radiographs. However, the proton-poor barium sulfate responsible for this radio-opacity is generally not detectable on MR imaging in the immediate post-operative period. Findings on MR imaging become more evident with elapsing time and when a foreign-body reaction to the sponge manifests as a mass lesion, which can mimic residual or recurrent intracranial tumor or abscess. Although preventive measures by our surgical colleagues to ensure accurate and correct sponge counts before and after wound closure is paramount, even the most fastidious efforts may rarely result in an inadvertently retained surgical sponge. The role of the radiologist is to recognize the imaging findings of this entity and its potential complications so that appropriate and prompt management can be initiated.

Topical haemostatic agents

BACKGROUND

A variety of local haemostatic agents is now available to stop troublesome bleeding. These agents are indicated for use during surgical interventions where conventional methods of haemostasis are not applicable because of the site of surgery or the degree of bleeding.

METHOD

A literature search using the PubMed and ISI Web of Knowledge databases identified relevant studies on topical haemostatic agents. Manufacturers' recommendations were also sought through commercial websites.

RESULTS AND CONCLUSION

A significant body of evidence now exists to support the use of topical haemostatic agents in a wide variety of clinical situations. The advantages and disadvantages of many of these agents are highlighted.

Postoperative hemicerebellar inflammation mimicking recurrent tumor after resection of a medulloblastoma. Case report

The authors present the case of a 4-year-old boy in whom a medulloblastoma in the left cerebellar hemisphere was successfully resected with no signs of residual tumor on the postoperative magnetic resonance (MR) images. A second MR imaging study performed 1 month after surgery demonstrated an extensive, contrast-enhancing lesion in the left cerebellar hemisphere, which simulated massive recurrent tumor, and repeated surgery was considered. A third postoperative MR imaging study, performed for evaluation of the craniospinal axis 10 days after the second postoperative study, still showed some contrast enhancement in the left cerebellar hemisphere, but the lesion had almost disappeared. Postoperative hemicerebellar inflammation seemed to be the most likely explanation. This case illustrates that early postoperative inflammation can mimic recurrent tumor on MR images obtained after resection of a medulloblastoma and caution should be taken in interpreting such images. Clinical history, neurological examination, laboratory findings, and repeated MR imaging studies can be helpful in evaluating the patient accurately.

Infection rates and healing using bone wax and a soluble polymer material

The effects of using a newly available water-soluble polymer bone hemostatic material in a contaminated environment were assessed in a rabbit tibial defect model. Infection rates and healing of polymer-treated bone were compared with the infection and healing of bone wax-treated bone and untreated controls after a bacterial challenge. Defects created in 24 rabbit tibias were treated with the polymer or bone wax, or left without a hemostatic agent. The defects were inoculated with Staphylococcus aureus ATCC-29213 (2.5 x 10(4) colony-forming units). After 4 weeks, all defects treated with bone wax were infected and osteomyelitis had developed, and none had evidence of bone healing. In the polymer and control groups, two defects in each group (25%) had osteomyelitis develop. The remaining six defects in each group (75%) showed no osteomyelitis and exhibited normal bone healing. The polymer-treated defects had a considerably lower rate of osteomyelitis and positive bone cultures compared with the bone wax-treated group. There were no differences between the polymer-treated and control groups in the rates of osteomyelitis, positive cultures, or bone healing. The use of a soluble polymer as an alternative to bone wax may decrease the rates of postoperative bone infections.

Aortic rings stimulate inflammatory angiogenesis in a subcutaneous implant in vivo model

Rat or mouse aortic rings produce angiogenic outgrowths in vitro through endogenous production of growth factors and inflammatory cytokines. To further investigate this process in vivo, collagen-Gelfoam constructs containing aortic rings were implanted subcutaneously in syngeneic animals. Aortic rings stimulated a prominent angiogenic response characterized by peri- and intra-aortic accumulation of florid granulation tissue. Conversely, implants without rings elicited a non-specific inflammatory reaction without significant angiogenesis. The angiogenic response to the rings peaked at day 14 and was followed by regression of neovessels, which were mostly reabsorbed by day 28. Gene expression studies showed upregulated expression of angiogenic growth factors and cytokines in implants with rings. Tracking experiments with LacZ expressing ROSA26 transgenic mice demonstrated that both the aorta and the host contributed to the angiogenic response. These studies show that the angiogenic properties of the rodent aorta can be studied in the live animal under conditions that can be monitored and quantified. This in vivo assay can be used to study the molecular mechanisms by which the arterial wall and its proangiogenic cytokines regulate formation of granulation tissue during wound healing.

Hydrogel-induced cervicomedullary compression after posterior fossa decompression for Chiari malformation. Case report

The use of an absorbable hydrogel dural sealant has been approved for neurosurgical applications with no published reports of complications to date. The authors present the case of a 13-year-old girl with syringomyelia and quadriparesis who underwent posterior fossa decompression and dural augmentation for Chiari malformation Type I. Dural closure was performed with a dural substitute patch, hydrogel dural sealant, and gelatin sponge. Magnetic resonance imaging, performed after initial postoperative improvement in the patient's quadriparesis deteriorated, demonstrated an expanding epidural mass collection causing cervicomedullary compression. Exploration on postoperative Day 15 revealed an expanded layer of hydrogel underlying a layer of gelatin sponge. The authors conclude that hydrogel dural sealants should be used cautiously in spaces that cannot tolerate significant mass effect.

Risk reduction of subdural collections following endoscopic third ventriculostomy

OBJECT

To evaluate the efficacy and safety using fibrin glue and absorbable hemostats for packing the endoscopic tract in a pediatric population in the prevention of subdural fluid collections after endoscopic third ventriculostomy.

MATERIALS AND METHODS

Twenty-one endoscopic third ventriculostomies were performed in 20 hydrocephalic children with a mean age of 22 months over a 4-year period using uniformly this technique. Six children, with age ranged 6 days to 22 months (mean 9 months), had severe ventriculomegaly with thin brain mantle less than 10 mm. There was no mortality and no permanent morbidity related to the endoscopic procedure. One child developed an asymptomatic collection, which could be managed conservatively and was most likely attributed to the young age of the child and the assumed poor cerebrospinal fluid absorption ability. Lost compliance of the brain parenchyma may play an additional role, which was not related to the thickness of the brain mantle. No adverse effects regarding the material used for sealing were observed over a mean follow-up of 23 months.

CONCLUSIONS

Subdural fluid collections could be prevented in 20 out of 21 procedures by using this technique regardless of the thickness of the brain mantle, the application of mixture of fibrin glue and hemostatic agents seems to be safe, and we consider this technique effective in reducing the risk of this potential complication.

Radiculopathy due to microfibrillar collagen hemostat mimicking recurrence of disc herniation

Microfibrillar collagen hemostat (Avitene) is an absorbable topical hemostatic agent prepared from purified bovine corium collagen. A 65-year-old woman presented with left buttock and lower extremity radicular pain. The patient underwent a disc excision in which Avitene was used to control venous bleeding from the epidural space. Leg pain decreased postoperatively, but she developed radicular pain when she started walking 3 days after the operation. Magnetic resonance imaging (MRI) performed post-operatively showed there was a mass lesion located between the dural sac and L5 nerve root. The lesion exhibited high signal intensity on T1-weighted images and higher signal intensity at the rim of the mass on T2-weighted images. A second operation performed 10 days later revealed that the nerve root was adherent to an extradural granulomatous mass associated with Avitene. Macroscopically, the resected mass was found to be composed mainly of microfibrillar collagen hemostat materials. Hemostat agents may produce a clinically symptomatic, radiologically apparent mass lesion. When considering a mass lesion arising after spine surgery, the differential diagnosis should include foreign body granuloma along with recurrent disc herniation and peridural scar formation.

Histological analysis of human diced cartilage grafts

BACKGROUND

Grafting the radix and dorsum of the nose has been controversial and the plastic surgery community has recently revisited diced cartilage grafts. Previous articles by the authors reported clinical failures of diced cartilage-Surgicel-wrapped grafts and the successful implementation of diced cartilage-fascia-wrapped grafts for rhinoplasty procedures. This article investigates four means of radix and dorsum augmentation, including banked and fresh septum.

METHODS

Twenty-seven human specimens were taken from rhinoplasty patients: six failed diced cartilage-Surgicel-wrapped grafts, eight diced cartilage-fascia-wrapped grafts, and 13 specimens of fresh cartilage or previously placed cartilage grafts. All were stained with hematoxylin and eosin, Masson's trichrome, safranin-O, glial fibrillary acidic protein, and Evans' van Gieson stains and analyzed for chondrocyte viability, matrix proteins, and regenerative potential of the cartilage.

RESULTS

The diced cartilage-Surgicel-wrapped grafts showed disorganized fibrosis, loss of nuclei in chondrocyte lacunae, and negative glial fibrillary acidic protein staining. All specimens contained remnants of Surgicel and evidence of foreign body reaction. The diced cartilage-fascia-wrapped grafts showed normal histologic characteristics, healthy cartilage pieces with viable chondrocytes in their lacunae, positive glial fibrillary acidic protein staining, and organized capsule of fibrosis surrounding the cartilage pieces. The fascia was viable and showed an organized architecture distinctly different from the disorganized scar tissue of the diced cartilage-Surgicel-wrapped grafts.

CONCLUSIONS

Given the histologic findings, diced cartilage-Surgicel-wrapped grafts absorbed due to foreign body reaction. Diced cartilage-fascia wrapped grafts survived and demonstrated normal cartilage viability. According to the clinical performance and analysis of these grafts, diced cartilage-fascia is the most reliable way to augment the nasal dorsum and radix with autologous diced cartilage.

Radiculopathy after lumbar discectomy due to intraspinal retained Surgicel: clinical and magnetic resonance imaging evaluation

BACKGROUND CONTEXT

Lumbar radiculopathy after lumbar spine surgery is an alerting sign usually caused by either a recurrent disc herniation or epidural hematoma. However, pressure on a spinal nerve root may also be exerted by a retained piece of Surgicel used to achieve hemostasis during lumbar spine surgical procedures.

PURPOSE

To describe a case of lumbar radiculopathy that was caused by a piece of Surgicel left in the spinal canal after operation for lumbar disc herniation.

STUDY SETTING

A case report of a retained piece of Surgicel being the cause of S1 radiculopathy.

METHODS

Patient interview, medical records, imaging studies, and literature review.

RESULTS

A 29-year-old man developed acute left S1 radiculopathy after a successful hemilaminectomy and discectomy operation for a L5-S1 disc herniation. In the magnetic resonance imaging studies that were performed, a postoperative hematoma could not be excluded and a reoperation revealed compression from Surgicel that was used for hemostasis. The patient was free of symptoms after reoperation.

CONCLUSIONS

This case depicts the difficulty in distinguishing-by means of magnetic resonance imaging-nerve root compression caused by a postoperative hematoma and a recurrent disc herniation, from that caused by a retained Surgicel. Therefore, hemostatic agents should be meticulously used in spine surgery.