Use of the prone oblique position in surgery for posterior fossa lesions

BACKGROUND

The lateral suboccipital approach has been conventionally performed with the lateral, park-bench, or sitting position and the midline suboccipital approach has been performed in the prone position. We attempt to show the advantages of the prone oblique position in the surgery for posterior fossa lesions.

METHODS

Twenty-two patients with posterior fossa lesions underwent surgery in the prone oblique position. The patients were fixed in the prone position while the operating table was rotated to raise the patient's shoulder. The surgeon sat beside the downward-shifted contralateral shoulder of the patient. With the lateral suboccipital approach, the neck of the patient was rotated to the side of the lesion. With the midline suboccipital approach, the neck was not rotated.

FINDINGS

With the lateral suboccipital approach, this position spread the transverse axis of the suboccipital triangle and eliminated the interference of the patient's shoulder, providing an operative field that is wider than the lateral position or park bench position in all cases. With the midline suboccipital approach, this position enabled the surgeon to operate on lesions located in the upper half of the posterior fossa, such as fourth ventricular lesions or infratentorial lesions, without the need for a looking up posture with overhanging of the operative microscope.

CONCLUSION

The prone oblique position offers the operator a panoramic view of the posterior fossa.

Prophylaxis to avert exacerbation/relapse of multiple sclerosis in affected patients undergoing surgery. Surgical observations and recommendations

To provide the neurological and neurosurgical communities with case evidence of postoperative multiple sclerosis (MS) relapse, literature review to support operative stress-induced relapse and recommendations for perioperative prophylaxis to prevent relapse in patients undergoing surgery. Two case studies are presented with recommendations based on an extensive review of the medical literature and personal experience to support perioperative prophylactic suggestions. Both patients fully recovered to preoperative functional status after treatment. We now routinely implement perioperative prophylaxis to MS patients undergoing surgery at our institution with no complications to date. Perioperative prophylaxis in patients with MS undergoing surgery can prevent relapse. It is of utmost importance that the surgical community realizes that prophylactic treatment is available and should be utilized during elective and emergent surgical situations.

Clinical review: Evidence-based perioperative medicine?

The present article outlines the basic principles of Evidence Based Medicine (EBM) and how they should guide clinical practice. The evidence supporting a selection of perioperative interventions is assessed against objective criteria. Many of the perioperative interventions that have been widely adopted into clinical practice are supported by very limited evidence. Conversely a high level of evidence supports other interventions that have not been so widely adopted. This may be due to concerns about limitations in the design and conduct of some of the clinical trials.

Discrepancies in current practice of pathological evaluation of sentinel lymph nodes in breast cancer. Results of a questionnaire based survey by the European Working Group for Breast Screening Pathology

AIMS

To evaluate aspects of the current practice of sentinel lymph node (SLN) pathology in breast cancer via a questionnaire based survey, to recognise major issues that the European guidelines for mammography screening should address in the next revision.

METHODS

A questionnaire was circulated by mail or electronically by the authors in their respective countries. Replies from pathology units dealing with SLN specimens were evaluated further.

RESULTS

Of the 382 respondents, 240 European pathology units were dealing with SLN specimens. Sixty per cent of these units carried out intraoperative assessment, most commonly consisting of frozen sections. Most units slice larger SLNs into pieces and only 12% assess these slices on a single haematoxylin and eosin (HE) stained slide. Seventy one per cent of the units routinely use immunohistochemistry in all cases negative by HE. The terms micrometastasis, submicrometastasis, and isolated tumour cells (ITCs) are used in 93%, 22%, and 71% of units, respectively, but have a rather heterogeneous interpretation. Molecular SLN staging was reported by only 10 units (4%). Most institutions have their own guidelines for SLN processing, but some countries also have well recognised national guidelines.

CONCLUSIONS

Pathological examination of SLNs throughout Europe varies considerably and is not standardised. The European guidelines should focus on standardising examination. They should recommend techniques that identify metastases > 2 mm as a minimum standard. Uniform reporting of additional findings may also be important, because micrometastases and ITCs may in the future be shown to have clinical relevance.

Pressurization of the Metastatic Femur During Prophylactic Intramedullary Nail Fixation

BACKGROUND

Venting during prophylactic nailing of metastatic femoral lesions may decrease intramedullary pressures and the risk of fat and tumor embolization. This study aimed to quantify maximum intramedullary pressure levels and durations, and to examine tumor displacement during prophylactic reamed intramedullary nailing of vented and nonvented metastatically involved femora.

METHODS

Proximal metastatic defects were simulated in six pairs of cadaveric femora and prophylactically treated using reamed intramedullary nailing with or without proximal and distal vents. Maximum pressures, durations of pressure exceeding embolic threshold levels (25 and 200 mm Hg), and tumor displacement were recorded.

RESULTS

Maximum pressures and durations of pressure exceeding embolic thresholds decreased more than 50% with venting (p < 0.05). Distal pressures surpassed the 25-mm Hg threshold even with venting. Post-test sectioning showed increased tumor disbursement in vented specimens.

CONCLUSIONS

Venting reduces pressurization during prophylactic reamed intramedullary nailing of femoral metastases, but may increase the spread of tumor to extraskeletal tissue if vented tissue is not contained.

Achieving vascular access success in the quality outcomes era

BACKGROUND

In 1997 the National Kidney Foundation put forth guidelines for hemoaccess through its Dialysis Outcomes Quality Initiative (DOQI). Some centers have been able to meet these standards; most have not.

METHODS

A retrospective review was made of our database of more than 3,500 hemoaccess procedures from 1986 to 2003.

RESULTS

Our approach, increased use of transposed fistulas and preoperative duplex mapping, has led to a fistula incidence (84%) and prevalence (54%) exceeding DOQI criteria. Meeting the DOQI guideline for thrombectomy rate (0.5 per year) is mostly achieved by increased use of fistulas. Additionally, access monitoring, as well as intraoperative angiography, angioplasty, stenting, and surgical revision, can aid in decreasing the frequency of occlusions (0.45 per year). This operative approach has led to a 98% success rate for surgical thrombectomy, exceeding the DOQI guideline of 85%. Earlier referrals from nephrologists have lowered the catheter use prevalence to 9%.

CONCLUSIONS

An aggressive approach to placing fistulas, maintaining the access, and receiving prompt referrals can lead to success in meeting DOQI criteria.

Regional audit: perioperative management of MRSA orthopaedic patients in the Oxford region

AIM

Methicillin resistant staphylococcus aureus (MRSA) colonisation or infection is of particular importance in patients undergoing operations involving implantable materials, such as in orthopaedic surgery. An audit of the perioperative management of orthopaedic patients in the Oxford region was carried out to assess the level of clinician awareness and the uniformity of current guidelines between hospitals.

METHODS

A postal questionnaire was designed for asking information on various aspects of perioperative management of MRSA patients and was sent to each hospital.

RESULTS

Responses were obtained from nine of 10 hospitals in the region. The average response rate for each hospital was 75%, and the overall individual response rate was 67.5% (27/40). Seventy-eight per cent of respondents knew that there was a pre-admission screening policy. Fifteen per cent were unaware of any MRSA policy. Forty-four per cent indicated that teicoplanin was used for prophylaxis in implant surgery whilst 44% used vancomycin. Eighteen per cent believed that cefuroxime was used for prophylaxis. Forty-eight per cent of hospitals had an MRSA-free zone for orthopaedic patients.

CONCLUSION

This study indicates a lack of uniformity in the perioperative management of MRSA-positive patients in the region and a lack of awareness of both MRSA guidelines and their implementation. Uniformity of MRSA guidelines is necessary to allow better clinician awareness and compliance, especially in surgical trainees who are travelling between different training hospitals in the region. Implementation of such a policy with re-audit of subsequent awareness and compliance is proposed.

Prospective Evaluation of Intraoperative Cochlear Implant Radiographs

OBJECTIVE

To investigate the clinical utility of intraoperative plain radiographs in cochlear implant surgery.

STUDY DESIGN

Prospective.

SETTING

Tertiary referral center.

PATIENTS

Eighty consecutive adult and pediatric cochlear implant operations at a facility capable of intraoperative radiographs were evaluated over 12 months.

INTERVENTIONS

Intraoperative plain radiographs to assess implant location and surgeon questionnaire.

MAIN OUTCOME MEASURES

Plain radiographic image interpretation and surgeon questionnaire.

RESULTS

In one revision surgery, the intraoperative plain radiograph was useful for confirming the cochleostomy site. In the remaining 79 operations, no changes in the electrode arrays were made on the basis of the information provided by intra-operative plain radiographs.

CONCLUSIONS

In this cohort, intraoperative plain radiographs were not useful for uncomplicated implant operations; however, they may be useful for complicated operations. These results may have implications for surgical cost and patient radiation exposure.

The use of frozen section and immunohistochemistry for sentinel lymph node biopsy in breast cancer

Intraoperative pathologic evaluation of the sentinel lymph node (SLN) may guide immediate (synchronous) completion axillary lymph node dissection (ALND) for up to two-thirds of patients with nodal disease for breast cancer. The false-negative rates average one-third of cases, and one must be aware of false-positive results as this would result in unnecessary and morbid completion ALND. Currently, the use of immunohistochemistry (IHC) is controversial. There is no question that cytokeratin staining improves the sensitivity; however, there is no evidence that any of these "positive" cells are clinically significant and warrant therapy. Prospective randomized trials will be necessary to confirm or debunk the hypothesis that "sub-micrometastatic" disease has clinical significance.

Relationship Between Processes of Care and Coronary Bypass Operative Mortality and Morbidity

BACKGROUND

Information is limited regarding the effects of processes of care on cardiac surgical outcomes. Correspondingly, many recommended cardiac surgical processes of care are derived from animal experiments or clinical judgment. This report from the VA Cooperative Study in Health Services, "Processes, Structures, and Outcomes of Cardiac Surgery," focuses on the relationships between 3 process groups (preoperative evaluation, intraoperative care, and supervision by senior physicians) and a composite outcome, perioperative mortality and morbidity.

METHODS

Data on 734 risk, process, and structure variables were collected prospectively on 3,988 patients who underwent coronary artery bypass grafting at 14 VA medical centers between 1992 and 1996. Data reduction was accomplished by examining data completeness and variation across sites and surgeon, using previously published data and clinical judgment. We then applied multivariable logistic regression to the 39 remaining processes of care to determine which were related to the composite outcome after adjusting for 17 patient-related risk factors and controlling for intraoperative complications.

RESULTS

Our first analysis showed several measures of operative duration, the use of inotropic agents, transesophageal echo, lowest systemic temperature, and hemoconcentration/ultrafiltration, to be powerful predictors of the composite outcome. Because the use of inotropic agents and operative duration may be related to an intermediate outcome (eg, intraoperative complications), we performed a second analysis omitting these processes. The use of intraoperative transesophageal echo and hemoconcentration/ultrafiltration remained significantly associated with an increased risk of an event (odds ratios 1.60 and 1.36, respectively).

CONCLUSIONS

Our results viewed in the context of past studies suggest the possibility that inotropic use, TEE, and hemoconcentration/ultrafiltration may have adverse effects on operative outcome. Further evaluation of these processes of care using observational data, as well as randomized trials when feasible, would be of interest.

Prélèvements anatomopathologiques en cancérologie : règles de bonnes pratiques au bloc opératoire

Concerning good practice for the management of histological cancer specimen, the main recommendations concern: (1) the quality of transmission in information between professionals; (2) the necessity of fresh, unfractionated, oriented surgical samples; (3) the importance of an appropriate storage condition for samples collected for extemporaneous examination, freezing or cell culture; (4) the quality of the deep freezer at temperatures of -80 degrees C or liquid nitrogen for frozen samples storage; (5) the importance of fixing tissues shortly after sample collection in buffered Formal solution in order to prevent cell lysis.

Review of the energy check of an electron-only linear accelerator over a 6 year period: sensitivity of the technique to energy shift

The calibration and monthly QA of an electron-only linear accelerator dedicated to intra-operative radiation therapy has been reviewed. Since this machine is calibrated prior to every procedure, there was no necessity to adjust the output calibration at any time except, perhaps, when the magnetron is changed, provided the machine output is reasonably stable. This gives a unique opportunity to study the dose output of the machine per monitor unit, variation in the timer error, flatness and symmetry of the beam and the energy check as a function of time. The results show that, although the dose per monitor unit varied within +/- 2%, the timer error within +/- 0.005 MU and the asymmetry within 1-2%, none of these parameters showed any systematic change with time. On the other hand, the energy check showed a linear drift with time for 6, 9, and 12 MeV (2.1, 3.5, and 2.5%, respectively, over 5 years), while at 15 and 18 MeV, the energy check was relatively constant. It is further shown that based on annual calibrations and RPC TLD checks, the energy of each beam is constant and that therefore the energy check is an exquisitely sensitive one. The consistency of the independent checks is demonstrated.

Intraoperative evaluation of axillary sentinel lymph nodes using touch imprint cytology and immunohistochemistry: I. Protocol of rapid immunostaining of touch imprints

AIMS

Sentinel Node Biopsy (SNB) is considered an accurate method of detecting axillary lymph node status in patients with small breast cancer. Combined with an accurate and rapid histopathology tool, it could spare this group of patients unnecessary Axillary Node Clearance (ANC) with its associated hazards. Intraoperative examination of SNB for cancer cells has been investigated using both Frozen Sections (FS) and Imprint Cytology (IC) stained with different stains. This study is devoted to establish a reliable and rapid protocol for immunostaining of touch imprints from SNB.

METHODS

We investigated two different EPOS (Enhanced Polymer One-Step staining--DAKO) anticytokeratin antibodies, five different tissue fixatives and different incubation periods and temperatures with both positive and negative controls.

RESULTS

We have developed a protocol, which produced good and consistent immunostaining of touch imprints. The initial results using this protocol are concordant with those of permanent Haematoxylin and Eosin (H&E) sections.

CONCLUSIONS

We propose this protocol for rapid immunostaining of touch imprints of SNB.

Thromboembolism Following Total Hip Replacement

Total hip replacement is an operation that is prone to thromboembolic complications, with potentially life-threatening consequences. However, the risk has declined substantially in the past three decades, reflecting advances in the understanding of the pathophysiology of thromboembolism and perioperative prophylaxis. The old concept of deciding thromboembolic prophylaxis after the completion of surgery is obsolete. In this review, we will concentrate on the main preventive measures that the medical and surgical team should implement prior to, during, and immediately after surgery.

Surgical gloves. How do you change yours?

Surgical gloves are frequently changed intraoperatively, and different techniques exist. We surveyed surgeons and scrub staff in our hospital and prospectively compared contamination between two glove changing techniques. We questioned 25 surgeons and 25 scrub staff regarding their intra-operative glove changing technique. Twenty scrub staff performed a standard 'surgical scrub', following which aliquots of fluorescent powder were applied symmetrically to each forearm prior to donning gown and gloves. Subjects were randomised to group 1-open technique (OT) followed by closed technique (CT), or group 2-CT followed by OT. Following unassisted glove change, glove and hand contamination was assessed.

Multiplane transesophageal echocardiography performed according to the guidelines of the American Society of Echocardiography in patients with mitral valve prolapse, flail, and endocarditis: diagnostic accuracy in the identification of mitral regurgitant defects by correlation with surgical findings

Multiplane transesophageal echocardiography is a useful tool to study mitral regurgitation. We evaluated the diagnostic accuracy of multiplane transesophageal echocardiography performed according to the guidelines of the American Society of Echocardiography. We used 4 midesophageal and 2 transgastric views in 313 patients with degenerative lesions, endocarditic lesions, or both to identify regurgitant defects, comparing transesophageal echocardiography results with surgical findings. The overall diagnostic accuracy using individual scallops was 97.2% (P <.00001) with a sensitivity of 96.6% and a specificity of 97.6%. Considering the single sections of the mitral valve, an accuracy of 98%, 97.1%, and 98%, was found, respectively, for the lateral, middle, and medial third of the anterior leaflet. For the posterior leaflet, the accuracy was 98% for the lateral scallop, 98.4% for the middle, and 96.1% for the medial. This strategy provides good accuracy in diagnosing both simple and challenging mitral-valve lesions and its widespread use should be recommended.

Evaluating intraoperative therapeutic and diagnostic interventions

A cost-conscious health care system requires detailed measures of its activities, including measurements of care provided to perioperative patients. Because there are no scoring systems that quantify the extent of intraoperative care interventions, we developed an intraoperative therapeutic intensity score (I-TIS). Physiological/biochemical monitoring and therapeutic interventions were assigned one to four points on the basis of the resource utilization and/or intensity of care they each reflect. Scoring was performed on actual patients, and the results were compared with ASA classification and surgical complexity. A 78-item scoring system was developed and assessed by using two patient groups. Group 1 (n = 307) entered the postanesthesia care unit (PACU) for short postoperative stays and had an I-TIS of 7.3 +/- 5.0; Group 2 patients (n = 443) were either admitted to the surgical, cardiothoracic, or neurosurgical intensive care units or had extended PACU stays, and they had an I-TIS of 25.2 +/- 12.4 (P < 0.001 versus Group 1). The correlation of I-TIS with the surgical complexity classification was r = 0.77, with ASA base relative value units was r(s) = 0.75, and with the ASA physical status classification was r(s) = 0.49. The score correlated well with surgical complexity and was able to differentiate between the intensity of care during various surgical procedures.

IMPLICATIONS

A scoring system to quantify the extent of nonsurgical intraoperative care was developed. The scoring system was validated and correlated well with surgical complexity; it was able to differentiate between the intensity of care provided during various surgical procedures.

Unexpected cardiac arrest among children during surgery, a North American registry to elucidate the incidence and causes of anesthesia related cardiac arrest

Relatively rare adverse events, such as unexpected cardiac arrest, are difficult to study in the clinical setting. These events are often unpredictable in their occurrence (prompting interest in their investigation) and do not occur with sufficient frequency in any single institution to provide an adequate sample for analysis. A disease-specific registry is an epidemiological technique that can be used to collect data on a set of relatively rare unpredictable events. This approach was adopted for investigation of cardiac arrest in children when it became apparent from analysis of malpractice claims that a significant clinical problem existed. This report provides a brief historical account of the development of the Pediatric Peri-Operative Cardiac Arrest (POCA) Registry and elaborates on the methodology including strengths, weaknesses, and practical implementation issues.