Sciatic and tibial neuropathies.

The sciatic nerve is the body's largest peripheral nerve. Along with their two terminal divisions (tibial and fibular), their anatomic location makes them particularly vulnerable to trauma and iatrogenic injuries. A thorough understanding of the functional anatomy is required to adequately localize lesions in this lengthy neural pathway. Proximal disorders of the nerve can be challenging to precisely localize among a range of possibilities including lumbosacral pathology, radiculopathy, or piriformis syndrome. A correct diagnosis is based upon a thorough history and physical examination, which will then appropriately direct adjunctive investigations such as imaging and electrodiagnostic testing. Disorders of the sciatic nerve and its terminal branches are disabling for patients, and expert assessment by rehabilitation professionals is important in limiting their impact. Applying techniques established in the upper extremity, surgical reconstruction of lower extremity nerve dysfunction is rapidly improving and evolving. These new techniques, such as nerve transfers, require electrodiagnostic assessment of both the injured nerve(s) as well as healthy, potential donor nerves as part of a complete neurophysiological examination.

Anterior Interosseus to Ulnar Motor Nerve Transfers: A Canadian Perspective.

BACKGROUND: The anterior interosseus nerve (AIN) to ulnar motor nerve transfer has been popularized as an adjunct to surgical decompression in patients with severe cubital tunnel syndrome (CuTS) and high ulnar nerve injuries. The factors influencing its implementation in Canada have yet to be described. METHODS: An electronic survey was distributed to all members of the Canadian Society of Plastic Surgery (CSPS) using REDCap software. The survey examined 4 themes: previous training/experience, practice volume of nerve pathologies, experience with nerve transfers, and approach to the treatment of CuTS and high ulnar nerve injuries. RESULTS: A total of 49 responses were collected (12% response rate). Of all, 62% of surgeons would use an AIN to ulnar motor supercharge end-to-side (SETS) transfer for a high ulnar nerve injury. For patients with CuTS and signs of intrinsic atrophy, 75% of surgeons would add an AIN-SETS transfer to a cubital tunnel decompression. Sixty-five percent would also release Guyon's canal, and the majority (56%) use a perineurial window for their end-to-side repair. Eighteen percent of surgeons did not believe the transfer would improve outcomes, 3% cited lack of training, and 3% would preferentially use tendon transfers. Surgeons with hand fellowship training and those less than 30 years in practice were more likely to use nerve transfers in the treatment of CuTS (P < .05). CONCLUSIONS: Most CSPS members would use an AIN-SETS transfer in the treatment of both a high ulnar nerve injury and severe CuTS with intrinsic atrophy.

Rehabilitation Following Nerve Transfer Surgery.

Nerve transfer surgery is an important new addition to the treatment paradigm following nerve trauma. The following rehabilitation plan has been developed over the past 15 years, in an interdisciplinary, tertiary peripheral nerve program at the "Roth|McFarlane Hand and Upper Limb Centre." This center evaluates more than 400 patients with complex nerve injuries annually and has been routinely using nerve transfers since 2005. The described rehabilitation program includes input from patients, therapists, physiatrists, and surgeons and has evolved based on experience and updated science. The plan is comprised of phases which are practical, reproducible and will serve as a framework to allow other peripheral nerve programs to adapt and improve the "Roth|McFarlane Hand and Upper Limb Centre" paradigm to enhance patient outcomes.

Postoperative management and rehabilitation after the supercharged end-to-side anterior interosseous nerve to ulnar motor nerve transfer: A report of 3 cases.

INTRODUCTION: Compressive ulnar neuropathy at the elbow is the second most common compressive neuropathy. Nerve transfers are used for severe ulnar neuropathies as a means of facilitating recovery. Hand therapy and rehabilitation after nerve transfers have not been extensively explored. PURPOSE OF THE STUDY: The aim of this repeated case study was to describe the responses, functional outcome, and neuromuscular health of three participants after the supercharged end-to-side (SETS) anterior interosseous nerve (AIN) to ulnar motor nerve transfer do describe the hand therapy and recovery of 3 cases reflecting different recovery potential mediators, trajectories, and outcomes. STUDY DESIGN: Repeated case study. METHODS: Three participants of similar age (76-80 years) that had severe ulnar neuropathy who underwent surgical treatment including a SETS AIN to ulnar motor nerve surgery were purposively selected from an ongoing clinical trial, based on their response to the surgical and the rehabilitation intervention (large, moderate, and small improvements). Clinical evaluations included measuring range of motion, strength testing, and clinical tests (ie, Egawa's sign) and, subjective assessment of rehabilitation adherence., Quick Disability of Arm, Shoulder and Hand and decomposition-based quantitative electromyography were performed at >23 months to evaluate patients. RESULTS: All the three participants completed the surgical and hand therapy interventions, demonstrating a variable course of recovery and functional outcomes. The Quick Disability of Arm, Shoulder and Hand scores (>23 months) for participants A, B, and C were 68, 30, and 18, respectively. The person with the least improvement had idiopathic Parkinson's disease, dyslipidemia, history of depression, and gout. Comparison across cases suggested that the comorbidities, longer time from neuropathy to the surgical intervention, and psychosocial barriers to exercise and rehabilitation adherence influenced the recovery process. The participants with the best outcomes demonstrated improvements in his lower motor neurons or motor unit counts (109 and 18 motor units in the abductor digiti minimi (ADM) and first dorsal interosseous, respectively) and motor unit stability (39.5% and 37.6% near-fiber jiggle in the ADM and first dorsal interosseous, respectively). The participant with moderate response to the interventions had a motor unit count of 93 for the ADM muscle. We were unable to determine motor unit counts and measurements from the participant with the poorest outcomes due to his physical limitations. CONCLUSIONS: SETS AIN to ulnar motor nerve followed by multimodal hand therapy provides measurable improvements in neurophysiology and function, although engagement in hand therapy and outcomes appear to be mediated by comorbid physical and psychosocial health.

Reverse End-to-Side Anterior Interosseous Nerve-to-Ulnar Motor Transfer for Severe Ulnar Neuropathy.

BACKGROUND: Reverse end-to-side anterior interosseous nerve transfer has been reported to enhance treatment of severe, proximal ulnar neuropathy. The authors report on patients with severe neuropathy treated with ulnar nerve transposition and distal reverse end-to-side anterior interosseous nerve transfer. METHODS: Thirty patients with severe ulnar neuropathy at the elbow were reviewed. Clinical parameters included preoperative and postoperative Medical Research Council muscle strength, clawing, and degree of wasting. Electrodiagnostic data included compound motor action potential and sensory nerve action potential amplitudes. Summary statistics were used for demographic and clinical data. The t test and Wilcoxon signed rank test were used where appropriate. RESULTS: Average follow-up was 18.6 months. Preoperatively, 20 patients had Medical Research Council less than or equal to grade 1 in hand intrinsics, small finger sensory nerve action potentials were absent in all patients except for three, and average compound motor action potentials were severely reduced (absent in nearly 40 percent) confirming severity. All groups had a statistically significant increase in strength. More than three-quarters of patients noted partial or complete resolution of clawing and intrinsic muscle wasting. Seventy-three percent of patients regained Medical Research Council greater than or equal to grade 3 and 47 percent achieved Medical Research Council greater than or equal to grade 4. Mean time to observation of nascent units was 8.5 months, and 77 percent of patients demonstrated an augmentation of motor unit numbers with forearm pronation on needle electromyography CONCLUSION:: Proximal subcutaneous ulnar nerve transposition when combined with reverse end-to-side anterior interosseous nerve-to-ulnar nerve transfer demonstrates significant clinical and electrodiagnostic improvement of intrinsic muscle function. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Treatment of Cervical Spondylotic Amyotrophy With Nerve Transfers.

Cervical spondylotic amyotrophy is characterized by severe, proximal upper extremity weakness including an inability to abduct the shoulder and flex the elbow. Treatment using both medical and surgical decompression approaches has produced variable results. This paper reports the use of nerve transfers (spinal accessory to suprascapular, flexor carpi ulnaris fascicle of ulnar to biceps motor branch, radial nerve branch to triceps to axillary) to restore shoulder and elbow function in a case of unilateral cervical spondylotic amyotrophy involving C5 and C6 myotomes. Evidence of regeneration was observed on electromyography as well as clinically at 5 months postoperatively. At 3 years after surgery, recovery of elbow flexion and shoulder abduction was Medical Research Council grade 4/5 with improved external rotation and considerably improved patient-rated Disabilities of the Arm, Shoulder and Hand scores. We propose that nerve transfers be considered along with other reconstruction modalities in the treatment of cervical spondylotic amyotrophy.

Nerve transfers and neurotization in peripheral nerve injury, from surgery to rehabilitation.

Peripheral nerve injury (PNI) and recent advances in nerve reconstruction (such as neurotization with nerve transfers) have improved outcomes for patients suffering peripheral nerve trauma. The purpose of this paper is to bridge the gap between the electromyographer/clinical neurophysiologist and the peripheral nerve surgeon. Whereas the preceding literature focuses on either the basic science behind nerve injury and reconstruction, or the surgical options and algorithms, this paper demonstrates how electromyography is not just a 'decision tool' when deciding whether to operate but is also essential to all phases of PNI management including surgery and rehabilitation. The recent advances in the reconstruction and rehabilitation of PNI is demonstrated using case examples to assist the electromyographer to understand modern surgical techniques and the unique demands they ask from electrodiagnostic testing.

Acquisition of evidence-based surgery skills in plastic surgery residency training.

INTRODUCTION: The teaching and learning of critical appraisal skills and evidence-based practices by surgical residents has been identified as an unmet need in many surgical training programs. METHODS: Monthly journal clubs over a calendar year were the setting for a critical appraisal curriculum. Preassigned homework assignments and carefully selected articles with specific methodologies were posted electronically and formed the course material. Pretests and posttests on medical statistics and methodology were administered. Presurveys and postsurveys on attitudes toward evidence-based surgery (EBS) were administered. RESULTS: Precourse surveys revealed a lack of confidence in residents' knowledge of epidemiology and biostatistics, with an increase in confidence postcourse (2.6 vs 2.9; p = 0.4). Precourse and postcourse, there was strong support for more critical appraisal training in residency (5.1 vs. 4.8; p = 0.1) and an agreement that understanding evidence-based practices is important for the clinical practice (4.6 vs. 4.6; p = 0.4) as well as the research endeavors of a plastic surgeon (5.4 vs. 5.5; p = 0.8). Pretest scores, when compared with PGY level, showed an increase in knowledge with increasing PGY level (p = 0.6). Average pretest scores were 6.5 of a total of 15 points, or 43%. Posttest scores were improved, at 7.8 of 15, or 52% (p = 0.6). Sixty-four percent of learners felt that journal club was a good venue for teaching critical appraisal skills precurriculum. Fifty percent of learners were still of that impression at course completion (p = 0.3). The modest improvement in test scores indicates an impact on critical appraisal skills, but reliance on journal clubs to teach these skills is insufficient. CONCLUSIONS: Through monthly journal clubs and self-directed assignments, critical appraisal skills were improved across PGY levels in an academic surgical training program; however, other settings and methods of teaching are required to augment a curriculum in evidence-based surgery.

A new, validated instrument to evaluate competency in microsurgery: the University of Western Ontario Microsurgical Skills Acquisition/Assessment instrument [outcomes article].

BACKGROUND: The authors present a model for microsurgery learning as well as a validated instrument to evaluate microsurgical competency. METHODS: Novice microsurgeons participated in three 3-hour sessions wherein they completed a number of increasingly complex, standardized microsurgical tasks. Performance was recorded and graded using a newly developed University of Western Ontario Microsurgery Skills Acquisition/Assessment (UWOMSA) instrument. The knot-tying and anastomosis modules contained three categories with five-point Likert scales. Each learner's performance was assessed by two blinded surgeons. Reznick's validated global rating scale for operative performance was utilized to establish criterion validity. Within-scale scores were compared via intraclass correlation and between-scale scores with Pearson correlation coefficient. Linear regression was used to evaluate the effect of various predictors on UWOMSA scores. RESULTS: Thirty-seven videos (9.6 hours) were reviewed, including 20 knot-tying sessions and 17 anastomoses. Interrater reliability of UWOMSA was high, with an intraclass correlation coefficient of 0.75 (0.57, 0.87). The intraclass correlation of the global rating scale was 0.79 (0.62, 0.89). Intrarater reliability of the UWOMSA was also high, with an intraclass correlation of 0.69 (0.48, 0.83). The intraclass correlation of the global rating scale was 0.69 (0.47, 0.84). Measures of criterion validity demonstrated strong agreement between UWOMSA and the global rating scale (Pearson correlation coefficient, 0.96; p < 0.001). Measures of construct validity demonstrated that higher scores on the UWOMSA were associated with faster knot tying (p < 0.0001) and higher postgraduate year level (p = 0.05). CONCLUSIONS: The UWOMSA instrument performed well in terms of reliability and validity. Further study is planned to assess the instrument's ability to predict microsurgical skills translation to the clinical setting.

Refining perforator selection for DIEP breast reconstruction using transit time flow volume measurements.

Transit time flow volume has been used in cardiac surgery to assess small vessel flow characteristics. This study examines the usefulness of transit time flow volume (TTFV) in assessing perforator vessels in deep inferior epigastric artery perforator (DIEP) flap harvesting. The purpose of this study was to evaluate the correlation among computed tomographic angiography (CTA), intraoperative TTFV measurements, and hand-held Doppler signals in identifying perforators. Ten consecutive free DIEP breast reconstructions were prospectively evaluated using CTA to identify abdominal wall perforators. Intraoperatively, perforating vessels >1 mm in diameter were evaluated with a conventional hand-held 8-MHz Doppler and a TTFV measurement device. Vessel location was correlated with preoperative CTA . Waveform patterns and TTFV measurements were recorded for each vessel and correlated with both CTA and hand-held Doppler signals. Of the 54 perforators identified, TTFV showed arterial flow waveforms in 15 of 16 perforators identified by CTA and in 2 of the remaining 38 vessels. The sensitivity and specificity of TTFV in identifying arterial perforators were 94 and 95%, respectively. In contradistinction, hand-held Doppler was misleading in 70% of vessels. TTFV distinguishes arterial from venous waveforms in vessels that appear arterial by hand-held Doppler signals. CTA and TTFV are highly correlated, and the use of TTFV may prevent poor perfusion seen in some DIEP flaps.

Development of a breast reconstruction satisfaction questionnaire (BRECON): dimensionality and clinical importance of breast symptoms, donor site issues, patient expectations, and relationships.

OBJECTIVES: To develop a valid, reliable and responsive, self-administered questionnaire to assess women's satisfaction with breast reconstruction. METHODS: Item generation: Three sources for item inventory were utilized: focus groups, expert panel, and literature review.Item reduction: Item impact scores were derived from patients and experts each ranking the importance and frequency of each item. Correlation between patient and expert scores was calculated. The highest impact questions were maintained. RESULTS: Four focus groups comprising 20 women generated 515 items, 10 experts developed 171 items, and literature review produced 227 items. These 913 potential items were reduced to 183 by combining redundancy. The 183 items underwent formal reduction by assessing importance and frequency of each item. Thirty-two of 40 reconstructed women and 19 of 19 experts responded to the mail-out. Seventy-seven items of the women's top 100 also made the experts' top 100 list. Intraclass correlation between patients and experts was 0.71 [0.62 0.77], indicating "good" but not "excellent" agreement, reinforcing the importance of patient involvement in questionnaire development. Women rated abdominal donor site issues higher than experts, and experts rated breast softness and symmetry higher than women. CONCLUSIONS: A 100-item pilot questionnaire for breast reconstruction satisfaction was developed for psychometric testing.

Factors affecting surgical wait times for breast reconstruction.

OBJECTIVE: To examine factors that affect wait times for women seeking breast reconstruction at a Canadian academic centre. METHODS: A retrospective audit of 57 women seeking breast reconstruction over a three-year period was completed. Comparisons of wait times were made considering the surgical pathology, timing of reconstruction (immediate versus delayed), urgency of pathology, method of reconstruction (implant versus autologous) and the number of surgeons involved. Specifically, the wait times from referral to specialist consultation, consultation to surgery, and referral to surgery were examined. RESULTS: WOMEN WITH ACTIVE CANCER (DUCTAL CARCINOMA IN SITU: 43 days, invasive cancer: 40 days) had shorter wait times compared with those who had no active cancer (benign/high risk: 242 days, previously treated cancer: 343 days) (P<0.05). Women seeking delayed reconstruction had longer wait times (359 days) from referral to surgery than women seeking immediate reconstruction (98 days) (P<0.0001). Women seeking reconstruction at the time of mastectomy, with benign/high-risk disease, waited longer (242 days) than those with ductal carcinoma in situ (43 days) or invasive cancer (40 days) (P<0.001). Wait times for autologous free tissue transfer (213 days) were not significantly longer compared with implant reconstruction (116 days) (P=0.27). Women with acute cancer experienced similar wait times for implant reconstruction (44 days) as for a free tissue transfer (56 days) (P=0.46). Women with no acute cancer had similar wait times for implant (239 days) as free tissue transfer (369 days) (P=0.25). Patients requiring only plastic surgeons involved in the reconstructive effort waited longer (one surgeon: 299 days, two surgeons: 550 days) than patients requiring either two plastic surgeons and one general surgeon (130 days) or one plastic surgeon and one general surgeon (82 days) (P<0.05). Although more coordination is required with three surgeons, this is frequently associated with a diagnosis of acute cancer and, therefore, wait times are shorter.

Sensibility following innervated free TRAM flap for breast reconstruction: Part II. Innervation improves patient-rated quality of life.

BACKGROUND: Restoring sensory innervation may be a useful adjunct in free flap head and neck reconstruction but, as yet, has not been shown to improve outcomes of breast reconstruction. The authors' previous study demonstrated objectively improved sensation in a group of innervated transverse rectus abdominis musculocutaneous (TRAM) flap breast reconstruction patients relative to noninnervated flaps. This study compared patient-rated outcomes of free TRAM breast reconstruction in innervated versus noninnervated flaps. METHODS: Twenty-seven women were randomized prospectively to undergo either innervated or noninnervated free TRAM flap breast reconstruction. For innervated flaps, the T10 intercostal nerve was harvested with the TRAM flap and neurotized to the T4 sensory nerve at the recipient site. Three validated outcome tools were administered after surgery: the Medical Outcomes Study 36-Item Short Form Health Survey, the Body Image after Breast Cancer Questionnaire, and the Functional Assessment of Cancer Therapy-Breast. Results were correlated with previously reported objective sensibility outcomes. RESULTS: Eighteen of 27 women returned their questionnaires a mean 48 months after free TRAM flap reconstruction. Demographic analysis revealed no significant differences in patient age, height, smoking, radiation therapy, and nipple-areola complex reconstruction between randomized patient groups. There was a statistically significant improvement in all three measures in patients who were randomized to receive innervated free TRAM flaps compared with those receiving noninnervated flaps. CONCLUSION: This study demonstrates that innervation of free TRAM flaps used for breast reconstruction not only improves sensibility but also has a positive effect on patient-rated quality of life.

Sensibility following innervated free TRAM flap for breast reconstruction.

BACKGROUND: The free transverse rectus abdominis musculocutaneous (TRAM) flap has proven to be a reliable means of recreating the aesthetic breast form after mastectomy. The purpose of this study was to determine whether neurotization of the free TRAM flap improved sensation of the reconstructed breast. METHODS: Twenty-seven patients undergoing 37 free TRAM flap reconstructions were randomized to receive either an innervated (12 patients, 18 breasts) or a noninnervated flap (15 patients, 19 breasts). A nerve repair between the T10 intercostal of the TRAM flap and the anterior sensory branch of the fourth intercostal nerve was performed for innervation. Sensory testing (Semmes-Weinstein monofilaments, hot-cold discrimination, two-point discrimination) was performed by one blinded examiner in a standardized pattern. RESULTS: Mean follow-up was 16 months. Demographic analysis revealed no significant differences in patient age, height, smoking, radiation therapy, and nipple-areola reconstruction between patient groups (p > 0.3). Patients in the noninnervated group, however, were heavier (p = 0.03). Preoperative sensation was not significantly different in the noninnervated and innervated groups. Postoperative pressure threshold and temperature discrimination were significantly improved in the innervated flaps (p < 0.05). Noninnervated flaps displayed a pattern of increasing sensibility from the center toward the periphery while innervated flaps regained sensation throughout. CONCLUSIONS: Innervation of the free TRAM flap provides improved sensation to the reconstructed breast and is a simple adjunct to breast reconstruction.

Outcomes in carpal tunnel syndrome: symptom severity, conservative management and progression to surgery.

PURPOSE: This study investigated the relationship between severity of symptoms and success of nonoperative and operative treatment in patients with carpal tunnel syndrome (CTS). METHODS: An observational cohort study regarding the management of CTS was conducted. Thirty patients referred to a tertiary hand centre with a diagnosis of CTS were prospectively followed. Twenty-five of the patients (47 affected hands) were available for long-term follow up to determine management outcomes. Self-report symptoms and physical impairments were assessed and documented at baseline, 6 weeks, and 12 weeks using the CTS Severity Score (SSS), the Disability-Shoulder, Arm and Hand Score (DASH), and the Levine Functional Score. Longer-term follow-up was conducted to identify status on outcome measures and whether patients proceeded to surgery. RESULTS: Those who proceeded to surgery (n = 27/47 hands) had higher initial CTS SSS and DASH scores and also maintained higher scores compared to those who improved with conservative management (p < 0.05). Improvements occurred in the SSS (P < 0.0001), Functional Score (P < 0.001), and DASH score (P < 0.05) following surgery in the patients resistant to conservative management. Recovery of grip and dexterity was less satisfactory. DISCUSSION: This study suggests that the SSS is useful in the triage of patients on surgical wait-lists as patients with high initial scores or failure to change in short-term follow-up are likely to proceed to surgical release. Despite prolonged symptoms and previous treatment, patients with lower SSS scores had moderate success with a second trial of conservative management.

Comparison of sagittal computed tomography and plain film radiography in a scaphoid fracture model.

PURPOSE: To compare computed tomography (CT) in the sagittal plane and plain film radiography in the diagnosis of scaphoid fracture and displacement. METHODS: Three groups of scaphoids (no fracture, undisplaced fractures, fractures with displacement > 1 mm) from 11 cadaver wrists were prepared. Each wrist then was imaged by using sagittal plane CT scans in the long axis of the scaphoid and plain film imaging using 6 standard scaphoid views. Eight readers from 3 specialties read each group of images. The sensitivity and specificity for the presence of fracture and fracture displacement were calculated in addition to interobserver and intraobserver reliabilities for each. RESULTS: Both x-ray and CT scans showed a high sensitivity and specificity in detecting the presence of a fracture with no interspecialty differences. The sensitivity for displacement greater than 1 mm was lower for both modalities with no inter-specialty differences. The specificities for x-ray and CT for detecting displacement greater than 1 mm were 84% and 89%, respectively. The poor sensitivity for detecting displacement was explained by the low sensitivity of CT in the diagnosis of radial/ulnar displacement compared with x-ray and the low sensitivity of x-ray in the diagnosis of volar/dorsal displacement compared with CT scans. When fellowship-trained hand surgeons reviewed CT scans and plain films together the sensitivity and specificity for fracture displacement increased significantly. Intraobserver and interobserver reliability for both x-ray and CT scans was excellent except for the reading of CT scans among emergency physicians and for the reading of plain x-rays among senior house staff, representing moderate agreement. CONCLUSIONS: Based on these results both CT scans in the sagittal plane and plain films accurately detect fractures with a high degree of interobserver and intraobserver reliability, but they fall short in detecting displacement greater than 1 mm.

Scalp and forehead reconstruction.

The reconstruction of defects that involve the scalp and forehead presents unique aesthetic and functional challenges. This article reviews the surgical anatomy of these regions and presents an algorithm for decision making in reconstructive surgery. Nonmicrosurgical techniques are briefly reviewed. The microsurgical reconstruction of scalp and forehead defects differs from the more common oropharyngeal reconstructions in several ways, including flap choices, choices for recipient vessels, and the opportunity to use conventional and microsurgical techniques simultaneously to improve outcomes. Each of these considerations is reviewed and the authors' preferred techniques presented.

A triple-blinded randomized trial comparing the hemostatic effects of large-dose 10% hydroxyethyl starch 264/0.45 versus 5% albumin during major reconstructive surgery.

In Canada, hydroxyethyl starch 264/0.45 (HES 264/0.45; molar weight 264 kDa, molar substitution 0.45) has largely replaced albumin as the colloidal fluid of choice for perioperative intravascular volume expansion. The maximum recommended dose of HES 264/0.45 is 28 mL/kg; however, there are no clinical data supporting this limit. In this study we compared the hemostatic effects of HES 264/0.45 versus 5% albumin in doses up to 45 mL/kg over 24 h during major reconstructive head and neck surgery. Fifty patients were randomized to receive HES 264/0.45 or 5% human albumin from the induction of anesthesia until 24 h thereafter. Both albumin and HES 264/0.45 effectively maintained physiologic variables in the perioperative and postoperative periods. The partial thromboplastin time and international normalized ratio were significantly increased in the HES 264/0.45 group compared with the albumin group after infusion of 30 mL/kg and 45 mL/kg (P < 0.05). Factor VIII activity and von Willebrand factor level were significantly reduced in the HES 264/0.45 group compared with the albumin group after infusion of 15 mL/kg, 30 mL/kg, and 45 mL/kg (P < 0.05). Significantly more subjects in the HES 264/0.45 group received allogeneic red blood cell transfusions (P < 0.02). We conclude that HES 264/0.45 infusions >30 mL/kg over 24 h impair coagulation to a greater extent than albumin, possibly leading to more allogeneic transfusions.