Neurosurgery and pituitary tumors: surgical indications and outcome

TWO MAIN FEATURE: Indication for surgery in patients with pituitary tumors depends first on the anatomical situation: the enclosed or invasive nature of the tumor. Total resection of an enclosed tumor, even if it is a huge one, can be expected to be successful. For invasive tumors, surgery will be subtotal unless the invasion is very limited. The second consideration is the efficacy and limitations of medical treatment. At present, only secreting pituitary adenomas are accessible to medical therapy. Other pituitary tumors, and non-functioning pituitary adenomas are not suitable for valid medical treatment and may warrant a surgical strategy. CHOICE OF THE OPERATIVE APPROACH: Anatomical and radiological considerations are determining. For secreting pituitary adenomas, first intention surgery via a transphenoidal access is advocated when surgery can be expected to achieve complete tumor resection without damaging the normal gland. For other cases, medical treatment has to be instituted prior to surgery which will be discussed in case of failure, intolerance or for tumor reduction. Transphenoidal surgery is strongly advocated in case of a pituitary incidentaloma with a visual danger, even in old patients. OUTCOME: Visual symptoms are often improved after neurosurgery for pituitary tumors. Hormone cure is frequent in microsecreting pituitary adenomas, rarely in invasive tumors.     

Endoscopic augmented reality navigation system for endonasal transsphenoidal surgery to treat pituitary tumors: technical note

OBJECTIVE: Endoscopes have been commonly used in transsphenoidal surgery to treat pituitary tumors, to compensate for the narrow surgical field. Although many navigation systems have been introduced for neurosurgical procedures, there have been few reports of navigation systems for endoscopic operations. This report presents our recently developed, endoscopic, augmented reality (AR) navigation system. METHODS: The technology is based on the principles of AR environment technology. The system consisted of a rigid endoscope with light-emitting diodes, an optical tracking system, and a controller. The operation of the optical tracking system was based on two sets of infrared light-emitting diodes, which measured the position and orientation of the endoscope relative to the patient's head. We used the system during endonasal transsphenoidal operations to treat pituitary tumors in 12 recent cases. RESULTS: Anatomic, "real," three-dimensional, virtual images of the tumor and nearby anatomic structures (including the internal carotid arteries, sphenoid sinuses, and optic nerves) were superimposed on real- time endoscopic live images. The system also indicated the positions and directions of the endoscope and the endoscopic beam in three-dimensional magnetic resonance imaging or computed tomographic planes. Furthermore, the colors of the wire-frame images of the tumor changed according to the distance between the tip of the endoscope and the tumor. These features were superior to those of conventional navigation systems, which are available only for operating microscopes. CONCLUSION: The endoscopic AR navigation system allows surgeons to perform accurate, safe, endoscope-assisted operations to treat pituitary tumors; it is particularly useful for reoperations, in which midline landmarks may be absent. We consider the AR navigation system to be a promising tool for safe, minimally invasive, endonasal, transsphenoidal surgery to treat pituitary tumors.     

Spinal intradural extramedullary tumors: the value of intraoperative neurophysiologic monitoring on surgical outcome

Nerve sheath tumors and meningiomas account for most intradural extramedullary (IDEM) tumors. These tumors are benign and amenable to complete surgical resection. In recent years, these surgeries are performed with intraoperative neurophysiologic monitoring (IONM) in order to minimize neurological injury, but the evidence for the statistical efficacy of this utility is lacking. This paper evaluates IONM benefits in IDEM tumor resection. Data of patients treated surgically for spinal intradural tumors from 1998 to 2003 was previously collected and analyzed. We retrospectively evaluated patients’ charts operated in the years 2011 to 2013. Patients’ medical files were reviewed including radiological examinations and electrophysiological reports. The data was collected and evaluated. Forty-one cases of meningioma or nerve sheath tumor resection surgery were performed in the study period. The surgical results were compared to 70 cases of historical controls. Demographic data was similar in these two groups. Sensitivity, specificity, and positive and negative predicted values of IONM were 75, 100, 100, and 97%, respectively. New neurological deficit rate was evident in 10 and 14% for the study and control groups, respectively (not significant). While IONM predicts neurological deficits with high accuracy level, this study does not suggest that there is a significant global benefit of IONM in these cases. As reported by others, in this series, the rate of new neurological deficits in non-monitored cases is similar to the monitored cases series; hence, IONM role in preventing new neurological deficits has yet to be proven.     

Utility of intraoperative endoscopy: Implications for surgical education

BACKGROUND: The use of intraoperative endoscopy by surgeons can identify pathology and help determine the appropriate procedure to perform. However, residency training in endoscopy is often variable and unstructured. The purpose of this study was to determine the indications for and impact of intraoperative endoscopy performed at the time of general surgical procedures. METHODS: The records of all patients who underwent intraoperative endoscopy from January 1998 to December 1999 were reviewed. The indications for endoscopy, endoscopic findings, the impact of these findings on the operation performed, complications, and whether the patient was spared from undergoing a second procedure on a separate date were noted. RESULTS: A total of 107 intraoperative endoscopic procedures were performed in 103 patients. Excluding breast, endocrine, central line, and peritoneal dialysis catheter cases, endoscopy was utilized in 5.1% of all general surgery procedures performed during this time period. In 91 patients (88%), the endoscopic procedure was planned preoperatively; in 13 (12%), intraoperative findings dictated its use. The most common indications for endoscopy were identification of lesions and determination of extent of resection (n = 27); evaluation of rectal bleeding (n = 21); colonic evaluation in patients with perianal infections (n = 13); evaluation of extent of injury in trauma cases (n = 8); evaluation of pain (n = 6); evaluation of intestinal tract hemorrhage (n = 6); performance of procedures such as placement of a biliary stent, placement of a nasojejunal tube, or polypectomy (n = 5); and surveillance of chronic disease (n = 5). In 37 patients (36%), the endoscopic findings affected the operation performed. Sixty-nine patients (67%) were spared an endoscopic procedure at a second date, which would have required additional sedation or anesthesia. There were no complications related to endoscopy. CONCLUSION: Intraoperative endoscopy is a valuable tool that can be performed safely for multiple indications and is frequently of value in determining the operation to be performed. Surgical residents should be trained in the indications for endoscopic evaluation as well as the competent performance of such procedures.     

Giant pituitary tumors: a study based on surgical treatment of 118 cases

BACKGROUND: The aim of the study is to analyze the nature, extensions, and dural relationships of hormonally inactive giant pituitary tumors. The relevance of the anatomic relationships to surgery is analyzed. METHODS: There were 118 cases of hormonally inactive pituitary tumors analyzed with the maximum dimension of more than 4 cm. These cases were surgically treated in our neurosurgical department from 1995 to 2002. Depending on the anatomic extensions and the nature of their meningeal coverings, these tumors were divided into 4 grades. The grades reflected an increasing order of invasiveness of adjacent dural and arachnoidal compartments. The strategy and outcome of surgery and radiotherapy was analyzed for these 4 groups. Average duration of follow-up was 31 months. RESULTS: There were 54 giant pituitary tumors, which remained within the confines of sellar dura and under the diaphragma sellae and did not enter into the compartment of cavernous sinus (Grade I). Transgression of the medial wall and invasion into the compartment of the cavernous sinus (Grade II) was seen in 38 cases. Elevation of the dura of the superior wall of the cavernous sinus and extension of this elevation into various compartments of brain (Grade III) was observed in 24 cases. Supradiaphragmatic-subarachnoid extension (Grade IV) was seen in 2 patients. The majority of patients were treated by transsphenoidal route. CONCLUSIONS: Giant pituitary tumors usually have a meningeal cover and extend into well-defined anatomic pathways. Radical surgery by a transsphenoidal route is indicated and possible in Grade I-III pituitary tumors. Such a strategy offers a reasonable opportunity for recovery in vision and a satisfactory postoperative and long-term outcome. Biopsy of the tumor followed by radiotherapy could be suitable for Grade IV pituitary tumors.     

Experience on the use of extra slim gastrointestinal endoscopes in ileal conduit endoscopy

Using extra slim gastrointestinal endoscopes, we have examined ileal conduits in two patients. This endoscope has almost the same caliber as a flexible cystoscope and has multiple manipulation levers and channels as ordinal gastrointestinal endoscopes. It is often difficult to examine ileal conduits with flexible cystoscopes because ileal conduits lack continent mechanisms and cannot be dilated adequately with water irrigation. With air insufflations, extra slim gastrointestinal endoscopes could adequately distend ileal conduits, and with multiple levers, they provided much more freedom of manipulation than flexible cystoscopes. Visualization of ureterointestinal anastomosis sites and biopsy of tumors could be performed very easily. We strongly recommend the use of extra slim gastrointestinal endoscopes than flexible cystoscopes when retrograde examinations and procedures are necessary in patients with ileal conduits.     

A prospective surgical outcome study assessing the impact of parathyroidectomy on symptoms in patients with secondary and tertiary hyperparathyroidism

BACKGROUND: To assess the impact of surgery on preoperative symptoms in secondary (2 degrees ) and tertiary (3 degrees ) hyperparathyroidism (HPT) compared with primary (1 degrees ) HPT. METHODS: Twenty-two patients with 2 degrees HPT and 10 with 3 degrees HPT were enrolled. Age-matched patients, 32 with 1 degrees HPT and 32 with thyroid disease were enrolled for comparison. An outcome questionnaire documented symptoms expressed as the median symptom index score (MSIS) preoperatively and at days 7 and 3 and 12 months postoperatively. RESULTS: Preoperatively, the MSIS for the groups with 3 degrees, 2 degrees, and 1 degrees HPT and thyroid disease was 225, 572, 372, and 146, indicating that patients with HPT were more symptomatic than those in the thyroid group (P<.05). Patients with 1 degrees HPT had a decrease in their MSIS at day 7 (195, P<.05) and at 3 and 12 months (159 and 156). Patients with 3 degrees HPT also had a decrease in their MSIS over time. Patients with 2 degrees HPT had a decrease in their MSIS at day 7 (469, P<.05); however, they remained more symptomatic at 3 and 12 months (410 and 355). CONCLUSIONS: Parathyroidectomy reduces many of the preoperative symptoms in HPT. Patients with 1 degrees and 3 degrees HPT have a similar resolution of their symptoms. Patients with 2 degrees HPT have an improvement in many of their symptoms, although they remain more symptomatic at 1 year.     

Peritoneoscopic versus surgical placement of peritoneal dialysis catheters: a prospective randomized study on outcome

The most commonly used technique for insertion of peritoneal dialysis (PD) catheters is open surgical approach by minilaparotomy. Percutaneous implantation via the peritoneoscopic technique is expanding. Studies have suggested that PD catheters placed peritoneoscopically have longer survival rate than surgically placed ones. However, these studies were not randomized, where the surgical group had more patients who were obese or had prior abdominal surgery, and therefore, the selection of patients may have biased the results. We conducted a prospective randomized study in which patients underwent PD catheter placement by either the surgical or the peritoneoscopic technique. In the period from October 1992 through October 1995, 148 double-cuff, curled-end, swan-neck PD catheters were placed in 148 patients. The outcome of the 76 patients in whom the PD catheters were placed peritoneoscopically was compared with that of the 72 patients in whom the catheters were placed surgically. Early peritonitis episodes (within 2 weeks of catheter placement) occurred in 9 of 72 patients (12.5%) in the surgical group, versus 2 of 76 patients (2.6%) in the peritoneoscopy group (P = 0.02). This higher rate of infection was most likely related to a higher exit site leak in the surgical group (11.1%) as compared with the peritoneoscopy group (1.3%). Moreover, peritoneoscopically placed catheters were found to have better survival (77.5% at 12 months, 63% at 24 months, and 51.3% at 36 months) than those placed surgically (62.5% at 12 months, 41.5% at 24 months, and 36% at 36 months) with P = 0.02, 0.01, and 0.04, respectively. We conclude that peritoneoscopically placed PD catheters have a longer survival rate than surgically placed ones. Furthermore, the rate of exit site leak and early infection is lower in the peritoneoscopic method.     

Development of a histological pseudocapsule and its use as a surgical capsule in the excision of pituitary tumors

OBJECT: The presence of a histological pseudocapsule around pituitary tumors was noted in the early 1900s. Since that time there has been no emphasis on the sequence of the stages of its development or on the relationship between these stages and the capacity to identify very small pituitary tumors at surgery in patients in whom preoperative imaging has been nondiagnostic. In addition, limited emphasis has been given to the pseudocapsule's use for selective and complete resection of pituitary adenomas. METHODS: The development of the pseudocapsule was examined by performing histological analysis of portions of pituitary glands removed during 805 operations for Cushing disease. Twenty-five adenomas, each measuring between 0.25 and 4 mm in maximum diameter, were detected in the excised specimens; 17 were adenocorticotropic hormone-positive adenomas and eight were incidental tumors (four prolactin-secreting and four nonsecreting lesions). In 16 tumors the size of the adenoma could be established. The distribution of tumor size in relation to the presence of a histological pseudocapsule indicates a transition from the absence of a reticulin capsule (tumor diameter < or =1 mm) through the initial compression of surrounding tissue (tumor diameter 1-2 mm) to the presence of a multilayered reticulin capsule observed when adenomas become larger (tumor diameter 2-3 mm). CONCLUSIONS: The absence of a reticulin capsule in cases of very small tumors may contribute to limited localization of these lesions during surgical exploration of the pituitary gland. In this article the authors describe surgical techniques in which the histological pseudocapsule is used as a surgical capsule during pituitary surgery. In their experience, recognition of this surgical capsule and its use at surgery has contributed to the identification of microadenomas buried in the pituitary gland, aided the recognition of subtle invasion of the pituitary capsule and contiguous dura mater, and enhanced the consistency of complete tumor excision with small and large tumors.     

内镜联合腹腔镜切除胃肠道间质瘤可行性研究

目的研究内镜联合腹腔镜对胃肠道间质瘤进行切除的可行性及其临床疗效。方法选择2008年4月至2012年4月间诊治的102例胃肠道间质瘤患者,其中男性60例,女性42例;年龄在20~79岁,平均为（57．8±6．7）岁。62例为胃间质瘤,行腹腔镜联合胃镜治疗;40例为肠道间质瘤,运用腹腔镜联合肠镜进行治疗。所有患者围手术期均行胃肠减压、补充液体、营养支持以及预防性应用抗生素。待肠道功能恢复后,拔除胃管。短期内进行流质饮食,逐步过渡到正常饮食。对所有患者进行半年以上的随访观察。结果所有患者均成功实施手术,病变部位定位准确,手术过程所需时间为40-80min,术中出血量在5-30ml,无中转开腹手术的患者;术后无吻合口出血及吻合口漏等并发症。所有患者随访半年,均无肿瘤复发。结论两镜联合治疗胃肠道间质瘤,疗效明确,手术的安全性高,同时降低了开腹手术给患者带来的痛苦和损伤,是目前治疗胃肠道间质瘤的较为理想的一种方法。     

The influence of surgical experience on the rate of intraoperative aneurysm rupture and its impact on aneurysm treatment outcome

BACKGROUND: The influence of surgical experience on the result of aneurysm surgery remains unclear. To determine the impact of surgical experience we considered the occurrence of intraoperative aneurysm rupture (IAR) during microneurosurgery for intracranial aneurysms as an objective factor that could be evaluated. METHODS: A retrospective study was performed on 379 consecutive patients with 490 cerebral aneurysms operated upon from 1989 to 1995. RESULTS: IAR occurred in 6.7% of aneurysms and 8.7% of patients. There was a direct inverse relationship between the annual caseload of the surgeon and the risk of IAR. New neurological deficits (NND) occurred in 21% of patients with IAR, which accounts for 1.8% of NND in all patients with aneurysms. CONCLUSION: Although there seems to be a direct relationship between surgical experience and the risk of IAR, the impact on the overall treatment outcome of cerebral aneurysms is rather limited.     

The impact of Clostridium difficile on a surgical service: a prospective study of 374 patients.

OBJECTIVE: To evaluate the epidemiology of Clostridium difficile colitis (CDC) in a subset of patients admitted specifically to a surgical service. SUMMARY BACKGROUND DATA: CDC is an increasingly prevalent nosocomial infection that can prolong hospitalization and adversely affect patient outcome. Although this disease has been investigated extensively in patients admitted to medical services, the incidence and risk factors for the development of this disease in patients admitted to a surgical service have not been studied. METHODS: Over a 5-month period, 374 patients admitted to the general, vascular, thoracic, and urologic surgery services were monitored for the development of symptomatic CDC (defined as >3 bowel movements per 24 hours and a positive cytotoxin assay or culture). RESULTS: Twenty-one patients developed CDC (incidence, 5.6%). Factors that independently predisposed to infection included admission from a skilled care facility, use of the antibiotic cefoxitin, and an operative procedure for bowel obstruction. Other factors associated with CDC included colectomy, treatment with any antibiotic, nasogastric tube suction, advanced age, and prior antibiotic treatment. Abdominal pain and fever were also more common in patients with CDC. Morbidity included prolonged hospitalization in all patients and urgent colectomy in one. CONCLUSIONS: CDC frequently affects surgical patients, producing morbidity ranging from mild diarrhea to life-threatening illness. A variety of factors, many of which are associated with intestinal stasis, predispose to the development of CDC.     

Remifentanil for intraoperative analgesia during the endoscopic surgical treatment of pituitary lesions

AIM: The authors have evaluated remifentanil for intraoperative analgesia in endonasal endoscopic surgery for pituitary lesions. METHODS: Experimental design: a perspective, randomized and comparative study between remifentanil and fentanyl for intraoperative analgesia was performed in an operating room of the neurosurgical department at University. Sixty patients of both sexes were studied and randomly divided into 2 groups. Patients were premedicated with fentanyl 0.15 microg.kg(-1) and atropine 0.01 microg.kg(-1) (group F) or with atro-pine and remifentanil 0.25 microg.kg(-1) min-1 (group R); induction was with propofol 2.0 microg.kg(-1) and maintenance with titrated infusion of propofol and for intraoperative analgesia, fentanyl as bolus injection of 1.0-1.5 microg.kg(-1) (group F) or a titrated infusion of remifentanil (group R). The following parameters were studied: MAP, HR, bleeding, awakening times, adverse effects and VAS. RESULTS: Much more stable hemodynamic parameters during surgery in patients treated with remifentanil; labetalol was administered in 10% of patients in group F; no significant differences as regards the adverse effects and VAS. Faster awakening time was obtained in the remifentanil group as compared with the fentanyl group. CONCLUSIONS: Remifentanil analgesia (mean dose of 0.37 microg.kg(-1).min-1) in patients undergoing endonasal endoscopic surgery of the sellar region provides a more efficacious cardiocirculatory control with reduced bleeding and faster psychosensorial recovery.     

Ruptured abdominal aortic aneurysm: Influence of intraoperative management on surgical outcome

Purpose: This study was designed to determine the influence of changes in intraoperative management on the outcome of ruptured abdominal aortic aneurysm (RAAA).Methods: Retrospective review of our surgical experience of RAAA identified 61 patients and was separated into two periods: 1986 to 1988 (group 1 [n = 21 patients]) and 1989 to 1994 (group 2 [n = 40 patients]). Since 1989 operations have been conducted by two vascular surgeons without systemic administration of heparin and with control of suprarenal aorta if extensive hematoma is present, use of collagen-impregnated grafts, preferential repair with aortoaortic grafting, and routine use of intraoperative autotransfusion.Results: Factors differing between the groups were use of intraoperative autotransfusion (4.76% in group 1 vs 80% in group 2, p < 0.00001), repair with tube grafting (42.8% in group 1 vs 80% in group 2, p = 0.003), number of packed homologous red blood cells (7.5 ± 5.2 units in group 1 vs 3.1 ± 3.6 units in group 2, p = 0.008), postoperative blood loss (365 ± 705 ml in group 1 vs 133 ± 351 ml in group 2, p = 0.01). The intraoperative mortality rate was significantly lower in group 2 (5% vs 28.6%, p = 0.016). The only predictive factor was the use of intraoperative autotransfusion with a lower mortality rate in patients undergoing autotransfusion (p = 0.029). The postoperative mortality rate was significantly lower in group 2 (20% vs 52.4%, p = 0.009). Predictive factors were use of intraoperative autotransfusion (p = 0.0009), age of the patients (p = 0.0039), and repair with tube graft (p = 0.039). The odds ratio of postoperative death was 25 times higher without intraoperative autotransfusion and seven times lower when a tube graft was used.Conclusion: Continuing efforts to achieve improvement in surgical technique and use of intraoperative autotransfusion were important determinants in lowering the postoperative mortality rate of RAAA to 20%. (J VASC SURG 1995;22:780-6.)     

Holographic reconstruction technology used for intraoperative real-time navigation in robot-assisted partial nephrectomy in patients with renal tumors: a single center study

BackgroundTo explore the efficacy and advantages of real-time navigation using holographic reconstruction (HR) technology combined with da VinciTM robotic system for partial nephrectomy (PN) in patients with renal tumor.MethodsThe clinical data of 41 patients with totally intrarenal tumors receiving robot-assisted partial nephrectomy (RAPN) from April 2018 to October 2020 in our department were collected and retrospectively analyzed. All operations were performed by the same surgeon. HR technology and three-dimensional (3D) reconstruction techniques were applied for real-time navigation to resect tumors using the da VinciTM robotic system. The relevant clinical parameters and surgical outcomes of the patients were recorded and analyzed.ResultsHR technology allowed accurate evaluation of tumors, renal hilus vessels, and surrounding organs during the operation. With real-time navigation HR, all cases were performed by RAPN. The mean operative time was 115.3±20.3 (range, 70–153) minutes, and the warm ischemia time (WIT) was 18.7±3.9 (range, 13–28) minutes. The estimated blood loss (EBL) was 98.8±18.7 (range, 60–141) mL. Negative surgical margins were reported in all cases. Patients with absence of grade ≤1 Clavien-Dindo complications. Compared with the clinical outcomes of standard RAPN, as reported in the literature, HR-assisted technology reduced the mean operative time, the WIT, and the EBL in patients undergoing RAPN. Therefore, combining HR with robotic abdominal surgery can enhance the efficiency of locating blood vessels and allow for more accurate resection of tumors.ConclusionsAs a novel and promising computer digital technology, HR can significantly improve the success of RAPN operations. This retrospective study demonstrated that HR-assisted operations resulted in shorter operation times and less perioperative complications and were thus safer and more effective in patients with renal tumors compared with RAPN not used HR.     

The use of high-resolution intraoperative ultrasound to localize gastrinomas: An initial report of a prospective study

We evaluated the use of high-resolution, real-time, B-mode, intraoperative ultrasound (IOUS) compared to simple manual palpation to localize gastrinomas during laparotomies in 10 consecutive patients with Zollinger-Ellison syndrome (ZES). All patients had clear biochemical evidence of ZES, and patients with metastatic gastrinoma identified preoperatively were excluded. Preoperative localization studies including ultrasound, computed tomography, and selective arteriography localized gastrinoma in 3 patients. Transhepatic portal venous sampling (PVS) for gastrin localized gastrin gradients to the pancreatic head region in 8 patients, and found no significant gastrin gradient in 2 patients. Gastrinomas were found at laparotomy and proven pathologically in 6 patients. Four patients had gastrinomas in the pancreatic head area as predicted by PVS; however, one patient had a tumor in the pancreatic tail and another in the jejunal wall. Palpation was the most sensitive intraoperative method to localize a gastrinoma (100% sensitivity). IOUS correctly imaged 3 gastrinomas (50% sensitivity). Palpation had 1 false-positive finding (80% specificity) and IOUS had 2 false-positive findings (60% specificity). All palpable masses that were also sonolucent on IOUS proved to be gastrinomas (3 patients). Thus, a combined positive finding raised the specificity and positive predictive value to 100%. We conclude that IOUS has utility in explorations for gastrinomas. Although not as sensitive or specific as palpation, IOUS can confirm, noninvasively, a suspicious palpable nodule. If IOUS fails to image a palpable nodule, our results suggest that the surgeon should still attempt to resect the nodule.

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Resumen Hemos hecho la valoración del uso de ultrasonografía intraoperatoria (USIO) de alta resolution, de tiempo real modo B, en comparacion con la simple palpation manual para localizar gastrinomas en el curso de la laparotomía en 10 pacientes consecutivos con el síndrome de Zollinger-Ellison (SZE). Todos los pacientes tenían clara evidencia bioquimica de SZE; los pacientes con gastrinoma metastásico identificados preoperatoriamente fueron excluidos. Los estudios preoperatorios, incluyendo ultrasonido, tomografía computadorizada, y arteriografía selectiva, localizaron el gastrinoma en 3 pacientes. El muestreo venoso portai transhepático para gastrina localizó gradientes de concentration de gastrina en la región de la cabeza del páncreas en 8 pacientes y no exhibieron gradientes significativos en 2 pacientes. Se encontraron gastrinomas en la operación, con comprobación patológica, en 6 pacientes. Cuatro pacientes presentaron gastrinomas en la cabeza del páncreas, tal como lo predijo el muestreo venoso portal transhepático; sin embargo, un paciente tenía un tumor en la cola del páncreas y otro en la pared yeyunal. La palpación fue el método intraoperatorio más sensible de localización del gastrinoma (sensibilidad 100%). La USIO delineó correctamente 3 gastrinomas (sensibilidad 50%). La palpación mostró 1 hallazgo falso positivo (especificidad 80%) y la USIO mostró 2 hallazgos falsos positivos (especificidad 60%). Todas las masas palpables que también aparecieron sonolucentes en la USIO probaron ser gastrinomas (3 pacientes). Por consiguiente, un hallazgo positivo combinado éleva la especificidad y el valor positivo de predicción a 100%. Nuestra conclusion es que la USIO es de utilidad en las exploraciones quirúrgicas por gastrinomas. Aunque no tan sensitiva o específica como la palpación, la USIO puede lograr la confirmación no invasiva de un nódulo palpable sospechoso. Pero aun si la USIO falla en la delineation de un nódulo palpable, nuestros resultados sugieren que el cirujano debe intentar la resección del nódulo.

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Résumé Les auteurs ont étudié l'emploi de l'échographie per-opératoire dans le dépistage des gastrinomes et l'ont comparé aux données de la simple palpation chirurgicale au cours de l'intervention. Chez 10 malades présentant un syndrome de Zollinger-Ellison tous les patients accusaient des signes biologiques patents du syndrome et les sujets porteurs d'un gastrinome avec métastase diagnostiqué avant l'intervention ont été exclus de l'étude. L'échographie, la tomodensitométrie, l'artériographie sélective permirent de localiser le gastrinome chez 3 malades. Le dosage étagé de la gastrine au niveau d'échantillons de sang portai fut positif chez 8 sujets porteurs d'un gastrinome siégeant au niveau de la tête du pancréas. Chez 6 malades, la tumeur fut découverte et sa nature fut prouvée histologiquement au cours de la laparotomie. Quatre gastrinomes siégeaient au niveau de la tête comme l'avait prédit l'échantillonnage sanguin, un était situé au niveau de la queue et un autre au niveau de la paroi jéjunale. La palpation chirurgicale fut la méthode de localisation la plus sensible (sensibilité de 100%). L'échographie mit en évidence 3 gastrinomes (sensibilité de 50%). La palpation se solda par un faux positif (spécificité de 80%) et l'échographie par 2 faux positifs (spécificité de 60%). Toutes les lésions palpables qui furent décelables à l'échographie répondirent à un gastrinome (3 cas). Ces faits démontrent que la combinaison des méthodes permet d'atteindre une spécificité et une valeur de prédiction de 100%. Les auteurs concluent que l'échographie per-opératoire n'est pas aussi sensible et spécifique que la palpation mais elle permet de confirmer sans aucun facteur d'aggravation, l'existence d'un nodule perçu par le palper. Si cette exploration est négative le chirurgien doit se fier à la palpation et réséquer la tumeur.

     

Risk-benefit analysis of navigation techniques for vertebral transpedicular instrumentation: a prospective study

Background Context

Pedicle screws in spinal surgery have allowed greater biomechanical stability and higher fusion rates. However, malposition is very common and may cause neurologic, vascular, and visceral injuries and compromise mechanical stability.