The innervated anterolateral thigh flap: anatomical study and clinical implications

During the past 20 years, the neural anatomy of many flaps has been investigated, although no extensive studies have been reported yet on the anterolateral thigh flap. The goal of this study was to describe the sensory territories of the nerves supplying the anterolateral thigh flap with dissections on fresh cadavers and with local anesthetic injections in living subjects. The sensate anterolateral thigh flap is typically described as innervated by the lateral cutaneous femoral nerve. Two other well-known nerves, the superior perforator nerve and the median perforator nerve, which enter the flap at its medial border, might have a role in anterolateral thigh flap innervation. Twenty-nine anterolateral thigh flaps were elevated in 15 cadavers, and the lateral cutaneous femoral nerve, the superior perforator nerve, and median perforator nerve were dissected. In the injection study, the lateral cutaneous femoral nerve, superior perforator nerve, and median perforator nerve in 16 thighs of eight subjects were sequentially blocked. The resulting sensory deficit from each injection was mapped on the skin and superimposed on the marked anterolateral thigh flap territory. The study shows that the sensate anterolateral thigh flap is basically innervated by all three nerves. The lateral cutaneous femoral nerve was present in 29 of 29 thighs, whereas the superior perforator nerve was present in 25 of 29 and the median perforator nerve in 24 of 29 thighs. Furthermore, in the proximal half of the flap, the lateral cutaneous femoral nerve lies deep, whereas the superior perforator nerve and median perforator nerve lie more superficially. Whereas the lateral cutaneous femoral nerve innervates the entire flap, the superior perforator nerve innervates 25 percent of the flap and the median perforator nerve innervates 60 percent of the flap. Clinically, a small anterolateral thigh flap (7 x 5 cm) can be raised sparing the lateral cutaneous femoral nerve and using only the selective areas innervated by the superior perforator and median perforator nerves. Alternatively, a large anterolateral thigh flap can be raised with this multiple innervation. This can be helpful if one wants to harvest the flap under local anesthesia. Sensate bilobed flaps can be harvested when dual innervated flaps are required.     

Two new cutaneous free flaps: the medial and lateral thigh flaps

Two new cutaneous free-flap donor areas are described on the medial and lateral sides of the thigh. The medial thigh flap is supplied by an unnamed artery from the superficial femoral artery and is drained by the accompanying venae comitantes. Its nerve supply is from the medial femoral cutaneous nerve. The lateral thigh flap has its vascular pedicle from the third perforating artery of the profunda femoral artery and its accompanying vein. The lateral femoral cutaneous nerve provides sensation over the area. These flaps provide a large surface area of both skin and subcutaneous tissue without the usual bulk of subcutaneous fat and muscle. Their desirable features include long vascular pedicles with large vessel diameters and potential of being neurovascular flaps with specific sensory nerve supply and predictable anatomy. The principal disadvantage is that the donor site may leave a slight contour defect with primary closure or require grafting when a large flap is taken. We predict that these flaps will become important donor sites for reconstructive problems requiring resurfacing of cutaneous defects in various anatomic areas.     

“Sensory Switching” in Elbow Reconstruction

In the treatment of the soft tissue defect of the elbow, flap reconstruction is necessitated in many cases because of thinness of soft tissue at this region. In addition, reacquirement of tactile sensation is desirable because of the anatomical and specific functions of the elbow. Of three cases treated for elbow defects, one was reconstructed with a pedicled island forearm flap containing the lateral cutaneous nerve of the forearm, another was reconstructed with a venoneuro-accompanying artery fasciocutaneous flap (VNAF flap) containing the basilic vein, and the third with the VNAF flap containing the cephalic vein. The three cases demonstrated a sudden change of sensory territory 4 to 6 months after surgery, which was confirmed by touching the reconstructed region with patients'' eye-closed: from its original territory to the elbow in a “switching”-like action. Here we describe and discuss the concept of “sensory switching.”     

Applied anatomy of the anterolateral femoral flap

A study of the source of the blood supply to the anterolateral femoral flap was carried out on 42 lower limbs of adult cadavers (among them 35 cadavers with injection of red latex and 1 with india ink into the arteries and 6 vascular cast specimens), and the surface locations of the vascular pedicle were detected on 50 healthy adults. It was found that the descending branch of the lateral circumflex femoral vessel was an ideal axial vessel. There are constant perforating branches of the myocutaneous artery or cutaneous branches from the intermuscular space to the anterolateral femoral skin. The area extends about 12 x 30 cm. Within the flap, the anterior branch of the anterolateral cutaneous nerve of the high is located. This flap has been widely used for free transplantation in China since 1983 with satisfactory results.     

The anterior tibial artery flap: anatomic study and clinical application

Satisfactory replacement of skin defects over the lower leg remains a difficult problem. Various forms of coverage, including, local rotation flaps, muscle flaps, and fascial and free flaps, have their specific indications and inherent disadvantages. In this work, a new axial skin flap based on perforating vessels in the territory of the anterior tibial artery is described. A series of 50 lower leg dissections was carried out in 25 fresh cadavers after latex injection into the femoral artery. Detailed studies of the cutaneous distribution of the anterior tibial artery showed that three main arteries perfuse the anterior lateral portion of the lower leg. The superior lateral peroneal artery and the inferior lateral peroneal artery interseptal cutaneous perforators arise at an average of 25.6 and 17.2 cm from the lateral malleolus, respectively. The superior lateral peroneal artery was present in 100 percent of the specimens, whereas the inferior lateral peroneal artery was present in 70 percent of the specimens. In their course, they give several muscular branches to the peroneus longus and brevis prior to perforating the fascia and arborizing in the subcutaneous tissues of the anterolateral portion of the leg. The average external diameter was 1.6 cm for the superior and 1.4 cm for the inferior lateral peroneal artery. The superficial peroneal nerve accessory artery is the third artery which contributes to the skin of the lower leg. It arises from the superior lateral peroneal artery in 30 percent of cases, from the inferior lateral peroneal artery in 40 percent, and from both in 30 percent. The artery runs along with the superficial peroneal nerve and gives several cutaneous perforators along its descending course. Several cutaneous axial flaps can be fashioned around this anatomy. The operative technique along with demonstrative clinical cases is presented followed by pertinent discussion.     

Evaluation of the Diagnostic Accuracy of Prototype Rapid Tests for Human African Trypanosomiasis

BackgroundDiagnosis of human African trypanosomiasis (HAT) remains a challenge both for active screening, which is critical in control of the disease, and in the point-of-care scenario where early and accurate diagnosis is essential. Recently, the first field deployment of a lateral flow rapid diagnostic test (RDT) for HAT, “SD BIOLINE HAT” has taken place. In this study, we evaluated the performance of “SD BIOLINE HAT” and two new prototype RDTs.Conclusions/SignificanceBoth “SD BIOLINE HAT” and the prototype devices performed comparably well to one another and also to the published performance range of the card agglutination test for trypanosomiasis in sensitivity and specificity. The performance of individual antigens enabled us to predict that an all-recombinant antigen RDT can be developed with an accuracy equivalent to “ SD BIOLINE HAT.” Such an RDT would have advantages in simplified manufacture, lower unit cost and assured reproducibility.     

Femoral Hernia in the Female

A study of 384 consecutive femoral herniorrhaphies performed upon female patients admitted to Shouldice Hospital, Toronto, during a 19-year period was carried out. Its main purpose was to describe the techniques used and to evaluate the results obtained. A careful 10-year follow-up plan for all cases existed.Two hundred and ninety-three operations were performed for the repair of simple femoral hernia; 91 were performed for the repair of femoral hernia which had developed following an initial ipsilateral inguinal or femoral repair performed previously, either in this hospital or elsewhere.The basic repair was subinguinal. Four modifications are described, one entirely subinguinal and three combined with exploration of the inguinal canal.The recurrence rate for simple femoral hernia in the female was 1.3% and for “recurrent” femoral hernia in the female, 5.5%.     

A new flap design: neural-island flap

This report introduces the "neural-island flap" concept, which represents a consistent and reliable skin flap design supplied only by the intrinsic vasculature of a cutaneous nerve. In this study, the lateral femoral cutaneous nerve was selected as the pedicle of the neural-island flap, and a standard skin flap, which is the territory of the accompanying vessels (i.e., iliac branches of the iliolumbar artery and vein), was elevated on the lower dorsal region of the rats. In a total of 92 Wistar rats, three experiments were performed. In part I (n = 24), the vascular anatomy of the lateral femoral cutaneous nerve was established by the methods of dissection, microangiography, nerve mapping, perfusion with colored latex and India ink, and histologic analysis. In part II (n = 46), the role of the cutaneous nerve in supporting an acutely elevated skin flap was explored by creating five flap groups as follows: group 1, conventional flap (artery, vein, and nerve intact); group 2, neural island flap (only the nerve intact); group 3, neurocutaneous flap (vein and nerve intact); group 4, denervated flap (artery and vein intact); and group 5, skin graft. In part III (n = 22), the role of a preliminary surgical delay procedure to augment the survival of the neural island flap was investigated. Results of the anatomic studies indicated a consistent perineural vasculature by the accompanying iliolumbar artery. Skin flaps survived totally in groups where the artery and vein were intact, whereas mean survival rates for the neural island flap and the neurocutaneous flap were 38.2 +/- 3.1 percent and 44.5 +/- 3.8 percent, respectively (p > 0.05). Results of part III of the experiment demonstrated a significantly higher survival for the delayed neural island flap (94.5 +/- 5.5 percent) compared with the acutely elevated neural island flap (p < 0.05). The perineural and intraneural vessels were found to be greatly dilated after a delay procedure, demonstrated by direct observation, microangiography, histologic analysis, dye injection study, and scanning electron microscopy. On the basis of this promising series of experiments, a clinical technique was developed using the sural neural-island flap. The flap was used to reconstruct lower extremity defects in four cases. A delay procedure was accomplished in the first stage by elevating a fasciocutaneous flap from the midcalf region based on a posterior skin bridge and the sural nerve. After a 2-week delay period, a sural neural-island flap was created based on the nerve and transposed to the defect. Flap survival was complete in all cases, with a satisfactory result. The authors conclude that this report proves for the first time that a robust and reliable skin flap can be created pedicled only by the intrinsic vasculature of a cutaneous nerve, after a proper surgical delay. The so-created neural-island flap design offers two novel advantages: (1) a very narrow pedicle and (2) a pedicle without any restriction to a specific pivot point, in addition to the previously described unique advantages of preservation of a major artery and avoidance of microvascular anastomoses.     

Leprosy in a prison population: A new active search strategy and a prospective clinical analysis

BackgroundThis study evaluates an active search strategy for leprosy diagnosis based on responses to a Leprosy Suspicion Questionnaire (LSQ), and analyzing the clinical, immunoepidemiological and follow-up aspects for individuals living in a prison population.MethodsA cross-sectional study based on a questionnaire posing 14 questions about leprosy symptoms and signs that was distributed to 1,400 prisoners. This was followed by dermatoneurological examination, anti-PGL-I serology and RLEP-PCR. Those without leprosy were placed in the Non-leprosy Group (NLG, n = 1,216) and those diagnosed with clinical symptoms of leprosy were placed in the Leprosy Group (LG, n = 34).FindingsIn total, 896 LSQ were returned (64%), and 187 (20.9%) of the responses were deemed as positive for signs/symptoms, answering 2.7 questions on average. Clinically, 1,250 (89.3%) of the prisoners were evaluated resulting in the diagnosis of 34 new cases (LG), based on well-accepted clinical signs and symptoms, a new case detection rate of 2.7% within this population, while the NLG were comprised of 1,216 individuals. The confinement time medians were 39 months in the LG while it was 36 months in the NLG (p>0.05). The 31 leprosy cases who responded to the questionnaire (LSQ+) had an average of 1.5 responses. The symptoms “anesthetized skin area” and “pain in nerves” were most commonly mentioned in the LG while “tingling, numbness in the hands/feet”, “sensation of pricks and needles”, “pain in nerves” and “spots on the skin” responses were found in more than 30% of questionnaires in the NLG. Clinically, 88.2% had dysesthetic macular skin lesions and 97.1% presented some peripheral nerve impairment, 71.9% with some degree of disability. All cases were multibacillary, confirming a late diagnosis. Anti-PGL-I results in the LG were higher than in the NLG (p<0.0001), while the RLEP-PCR was positive in 11.8% of the patients.InterpretationOur findings within the penitentiary demonstrated a hidden prevalence of leprosy, although the individuals diagnosed were likely infected while living in their former communities and not as a result of exposure in the prison. The LSQ proved to be an important screening tool to help identify leprosy cases in prisons.     

Providing useful and protective sensibility to the sitting area in patients with meningomyelocele

About 62 percent of the patients with meningomyeloceles will have essentially normal sensation in the area supplied by the lateral femoral cutaneous nerve (which is also the territory of the extended tensor fasciae latae flap), despite the fact that they may have complete anesthesia in their sitting area. In these, pressure sores can be healed and future ones prevented by transposing a sensation-bearing tensor fasciae latae flap to provide virtually normal sensibility in the sitting area.     

PAROTID TUMOR OPERATIONS—The Case Against Enucleation

So-called mixed “encapsulated” parotid tumors are best managed by surgical procedures which avoid contact with the “capsule.” Enucleation is often a hazardous and incomplete procedure. Subtotal or total parotidectomy with exposure of the facial nerve to avert accidental damage to it is the treatment of choice.Microscopic study of the periphery of such tumors reveals that the “capsule” does not fully encapsulate; hence, enucleation and lesser procedures may leave neoplastic tissue behind.Surgical procedures to achieve complete excision without endangering the facial nerve were carried out in 123 cases. There was local recurrence in one case.     

Reversed forearm island flap supplied by the septocutaneous perforator of the radial artery: anatomical basis and clinical applications

The cutaneous perforators of the radial artery adjacent to the superficial branch of the radial nerve and the lateral antebrachial cutaneous nerve were investigated, and the vascular anatomical features of the reversed forearm island flap supplied by those accompanying perforators were documented. Ten fresh cadavers were systemically injected with lead oxide, gelatin, and water. Twenty forearms were then dissected, and an overall map of the cutaneous vasculature and source vessels was constructed. The accompanying arteries were observed to lie along the lateral antebrachial cutaneous nerve and the superficial branch of the radial nerve and to nourish the skin through cutaneous branches. Vascular communication among these cutaneous vessels was evaluated, to determine the cutaneous vascular territory of the radial forearm flap. This anatomical information facilitates flap design in the forearm region. Clinical experience regarding the usefulness of the reversed forearm island flap for hand reconstruction for a series of five patients is presented.     

STRETCHING OF THE SCIATIC NERVE—A Means of Relieving Postoperative Pain Following Removal of Ruptured Lumbar Intervertebral Discs

Stretching the sciatic nerve for the relief of “sciatica” was frequently employed before 1900 and was subsequently abandoned, probably because it was done without sufficient scrutiny of the indications. The procedure has recently been employed in cases in which “sciatica” remains following the operative removal of ruptured intervertebral discs, and it has been instrumental in relieving postoperative “sciatica” when the cause was the formation of adhesions about the lumbar nerve roots. If the nerve root is compressed by recurrent disc protrusion or by adjacent bone, the manipulation usually increases the pain, a phenomenon that has been helpful from a diagnostic standpoint.     

Longitudinal Treatment Outcomes of Microsurgical Treatment of Neurosensory Deficit after Lower Third Molar Surgery: A Prospective Case Series

Objective

To prospectively evaluate the longitudinal subjective and objective outcomes of the microsurgical treatment of lingual nerve (LN) and inferior alveolar nerve (IAN) injury after third molar surgery.

Materials and Methods

A 1-year longitudinal observational study was conducted on patients who received LN or IAN repair after third molar surgery-induced nerve injury. Subjective assessments (“numbness”, “hyperaesthesia”, “pain”, “taste disturbance”, “speech” and “social life impact”) and objective assessments (light touch threshold, two-point discrimination, pain threshold, and taste discrimination) were recorded.

Results

12 patients (10 females) with 10 LN and 2 IAN repairs were recruited. The subjective outcomes at post-operative 12 months for LN and IAN repair were improved. “Pain” and “hyperaesthesia” were most drastically improved. Light touch threshold improved from 44.7g to 1.2g for LN repair and 2g to 0.5g for IAN repair.

Conclusion

Microsurgical treatment of moderate to severe LN injury after lower third molar surgery offered significant subjective and objective sensory improvements. 100% FSR was achieved at post-operative 6 months.     

Conditional Probability Analyses of the Spike Activity of Single Neurons

With the objective of separating stimulus-related effects from refractory effects in neuronal spike data, various conditional probability analyses have been developed. These analyses are introduced and illustrated with examples based on electrophysiological data from auditory nerve fibers. The conditional probability analyses considered here involve the estimation of the conditional probability of a firing in a specified time interval (defined relative to the time of the stimulus presentation), given that the last firing occurred during an earlier specified time interval. This calculation enables study of the stimulus-related effects in the spike data with the time-since-the-last-firing as a controlled variable. These calculations indicate that auditory nerve fibers “recover” from the refractory effects that follow a firing in the following sense: after a “recovery time” of approximately 20 msec, the firing probabilities no longer depend on the time-since-the-last-firing. Probabilities conditional on this minimum time since the last firing are called “recovered probabilities.” The recovered probabilities presented in this paper are contrasted with the corresponding poststimulus time histograms, and the differences are related to the refractory properties of the nerve fibers.     

Production of Artificial “Case Histories” by using a Small Computer

This paper describes a method of producing artificial “case histories” by using probability theory and clinical data from a series of 600 patients with acute abdominal pain. A series of 12 such cases were distributed to clinicians, medical students, medical secretaries and technicians, and members of the general public. For each “case” most clinicians concurred with the intended diagnosis. So did the medical secretaries and technicians; indeed this group were more confident of their chosen diagnoses than were the clinicians.It is suggested that clinicians are concerned to a large extent with the consequences of a diagnosis as well as its accuracy, and are motivated to some degree by a fear of the consequences of failure. They may be justified in adopting this policy, for when “errors” in diagnosis are harshly penalized the clinicians were infinitely more effective than any of the other groups.     

Caesarean Section: Could Different Transverse Abdominal Incision Techniques Influence Postpartum Pain and Subsequent Quality of Life? A Systematic Review

The choice of the type of abdominal incision performed in caesarean delivery is made chiefly on the basis of the individual surgeon’s experience and preference. A general consensus on the most appropriate surgical technique has not yet been reached. The aim of this systematic review of the literature is to compare the two most commonly used transverse abdominal incisions for caesarean delivery, the Pfannenstiel incision and the modified Joel-Cohen incision, in terms of acute and chronic post-surgical pain and their subsequent influence in terms of quality of life. Electronic database searches formed the basis of the literature search and the following databases were searched in the time frame between January 1997 and December 2013: MEDLINE, EMBASE Sciencedirect and the Cochrane Library. Key search terms included: “acute pain”, “chronic pain”, “Pfannenstiel incision”, “Misgav-Ladach”, “Joel Cohen incision”, in combination with “Caesarean Section”, “abdominal incision”, “numbness”, “neuropathic pain” and “nerve entrapment”. Data on 4771 patients who underwent caesarean section (CS) was collected with regards to the relation between surgical techniques and postoperative outcomes defined as acute or chronic pain and future pregnancy desire. The Misgav-Ladach incision was associated with a significant advantage in terms of reduction of post-surgical acute and chronic pain. It was indicated as the optimal technique in view of its characteristic of reducing lower pelvic discomfort and pain, thus improving quality of life and future fertility desire. Further studies which are not subject to important bias like pre-existing chronic pain, non-standardized analgesia administration, variable length of skin incision and previous abdominal surgery are required.     

Proposed Classification of Auriculotemporal Nerve,Based on the Root System

The topography of the auriculotemporal nerve (ATN) root system is the main criterion of this nerve classification. Previous publications indicate that ATN may have between one and five roots. Most common is a one- or two-root variant of the nerve structure. The problem of many publications is the inconsistency of nomenclature which concerns the terms “roots”, “connecting branches”, or “branches” that are used to identify the same structures. This study was performed on 80 specimens (40 adults and 40 fetuses) to propose a classification based on: (i) the number of roots, (ii) way of root division, and (iii) configuration of interradicular fibers that form the ATN trunk. This new classification is a remedy for inconsistency of nomenclature of ATN in the infratemporal fossa. This classification system has proven beneficial when organizing all ATN variants described in previous studies and could become a helpful tool for surgeons and dentists. Examination of ATN from the infratemporal fossa of fetuses (the youngest was at 18 weeks gestational age) showed that, at that stage, the nerve is fully developed.     

Tuberculosis: A Challenge to the General Practitioner

Of 157 patients dying of tuberculosis in Ontario (1960) 132 (87.4%) suffered from the pulmonary form of the disease (incidence 2.6 per 100,000). In the same year, 1632 of 1847, or 88.3%, active new cases reported had the pulmonary type and 183 additional cases were reported without details as to type of disease. Thus, in 1960, a total of 2030 new cases of tuberculosis were reported in Ontario.Of 1367 patients with pulmonary tuberculosis (reinfection type), 357 (26.1%) had “far advanced” disease and 613 (44.8%) had “moderately advanced” disease.This high percentage of patients with “moderately advanced” to “far advanced” disease at the time of diagnosis constitutes the real challenge to physicians in private practice, who made the diagnosis in 45% of cases.Emergence of resistant strains of bacteria increases the urgency of prompt diagnosis and treatment. The most vulnerable population segment is the 15-30 year age-group, many of whom are negative intracutaneous reactors. A high index of suspicion is necessary, particularly in certain segments of the population with a high incidence of infection, combined with a careful history, meticulous physical examination, intracutaneous tests, chest and other radiographs, and appropriate bacteriological studies.     

Human Quadrupeds,Primate Quadrupedalism,and Uner Tan Syndrome

Since 2005, an extensive literature documents individuals from several families afflicted with “Uner Tan Syndrome (UTS),” a condition that in its most extreme form is characterized by cerebellar hypoplasia, loss of balance and coordination, impaired cognitive abilities, and habitual quadrupedal gait on hands and feet. Some researchers have interpreted habitual use of quadrupedalism by these individuals from an evolutionary perspective, suggesting that it represents an atavistic expression of our quadrupedal primate ancestry or “devolution.” In support of this idea, individuals with “UTS” are said to use diagonal sequence quadrupedalism, a type of quadrupedal gait that distinguishes primates from most other mammals. Although the use of primate-like quadrupedal gait in humans would not be sufficient to support the conclusion of evolutionary “reversal,” no quantitative gait analyses were presented to support this claim. Using standard gait analysis of 518 quadrupedal strides from video sequences of individuals with “UTS”, we found that these humans almost exclusively used lateral sequence–not diagonal sequence–quadrupedal gaits. The quadrupedal gait of these individuals has therefore been erroneously described as primate-like, further weakening the “devolution” hypothesis. In fact, the quadrupedalism exhibited by individuals with UTS resembles that of healthy adult humans asked to walk quadrupedally in an experimental setting. We conclude that quadrupedalism in healthy adults or those with a physical disability can be explained using biomechanical principles rather than evolutionary assumptions.