Versatility of the Pedicled ALT Flap in Defect Reconstruction : Experience of a Unit in Rural Sub-Saharan African

The ANNALS of AFRICAN SURGERY, January 2018 Volume 15 Issue 1 34 Abstract Background: The free anterolateral thigh flap with its large caliber vessels, a reliable skin territory and minimal donor site morbidity is the reconstructive surgeons’ workhorse. The pedicled flap though not as popular, has been used extensively for the reconstruction of defects from the mid-leg to the epigastrium. The favorable profile of the anterolateral thigh flap, with minimal variability of its vascular anatomy and donor site complications is well described in most races; literature of its use in sub-Saharan Africa is scanty. Methods: The author describes the use of the anterolateral thigh flap in a series of 17 patients in a rural African hospital, illustrating its versatility as well as the complications associated with its use in this patient population. Results: Seventeen patients with


Introduction
The free anterolateral thigh (ALT) flap with its large caliber vessels, reliable skin territory and minimal donor site morbidity is the reconstructive surgeons' workhorse.Flap components can be customized depending on the needs of the defect to include any or all of the following: skin paddle(s), fascia, and vastus lateralis muscle.The pedicled ALT flap though not as popular, has been used for the reconstruction of defects from mid-leg to the epigastrium (1)(2)(3)(4)(5).There is limited literature on the use of the ALT flap in black Africans (1)(2)(3).Its vascular anatomy, intra-individual, intra-and inter -racial variability in Caucasians and Asians have been widely reported (5).In black Africans on the other hand, the ALT flap vascular anatomy is largely presumed to be similar to that described in other races as reported anatomical and clinical studies are twenty antero-lateral thigh flaps were followed for an average of 24 months.Conclusions: The pedicled antero-lateral thigh flap is an excellent reconstructive tool with very good results in the black African population.This versatile flap has low donor site morbidity.The risk of developing hypertrophic scars and keloids remains a real concern in Black patients and longer term follow-up and a larger number of patients are needed to establish this potential complication.scanty (7).While skin flap perforators classically originate from the descending branch of the lateral circumflex femoral artery, a wide variability including complete absence has been described (8).To avoid intra-operative complications therefore, some authors advocate for pre-operative vascular studies (6)(7)(8).However, considering the favorable profile of the ALT flap, the cost implications of vascular studies and other difficulties related to our clinical and social environment, we do not require vascular studies for our patient population.An internet search using the Google® search engine and PubMed for 'anterolateral thigh flap Africa, African, Kenya' and Bioline International and African Journals Online sites for 'anterolateral thigh flap' returned two papers (1,2).PubMed had one additional paper (9).The limited literature on the use of the ALT flap in black Africans

Methods
Charts of all patients who had a pedicled ALT flap in our institution between 2009 and 2016 were reviewed.

Case Presentations
A total of 17 patients were managed with a pedicled ALT flap over this period (Table 1).There were 15 males and two females, aged 9 to 50, (average 32 years).Eight patients (47%) were treated for post-traumatic defects (Figure 1).The patients were followed up for between 6 and 48 months.Four illustrative cases are described.The ANNALS of AFRICAN SURGERY, January 2018 Volume 15 Issue 1 36 Case 1 A 35 year-old young man who had sustained a gunshot wound injury to his abdomen and pelvis six weeks prior to referral to the authors' institution presented with injuries of the urinary bladder and bowel.Following his initial surgery, he had undergone multiple attempts to close the anterior abdominal wall because of repeated abdominal wound dehiscence.A final attempt at abdominal wound closure using an abdominal wall component separation failed (Figure 1).A 35 year-old male sustained a gunshot wound injury to his pelvis 10 years prior to his presenting to our hospital.He had sustained injuries to his rectum and urethra; a sigmoid colostomy and suprapubic cystostomy had been used to divert stool and urine, respectively.On examination, he had a 'watering can perineum' (10).In 2009, the perineal fistuli were excised, and the urethra reconstructed with a 'Singapore flap' (11).Post-operatively he had a good voiding stream for about a year, after which he started straining.Subsequently, he noted urine leaking from his anus.An attempted urethroscopy failed as the urethra could not be visualized beyond the site of the previous anastomosis.The urethra was also lined with a lot of hair.When contrast was instilled into the bladder, it leaked into the rectum, though a prostato-rectal fistula.
A urethral exploration was performed: intra-operatively, the urethra was found to have been completely obstructed by a urethral beard and three stones (Figure 3).Immediately proximal to this obstruction was the prostato-rectal fistula.An ALT flap with no skin was elevated, and a full thickness groin skin graft used to line the urethra, to replace the segment reconstructed using the Singapore flap, as the thigh skin was also hairy.Skin lining on the inside was avoided because of the risk of developing a urethral beard.At 3 weeks follow-up, the urethral catheter was pulled out (Figure 4).He has a good voiding stream, with no rectal leak.A 30 year-old male was transferred to our institution after initial care at another facility for injuries to all four limbs following a motor vehicle accident.All the wounds were heavily infected.The left leg required a below-knee amputation.The right knee was infected with exposed necrotic bone (Figure 5).In order to preserve this extremity, a reverse ALT flap with vastus lateralis muscle was used to cover the knee joint and proximal exposed tibia.Flap tip necrosis resulted from the infection; this was debrided, and the defect covered with a split-thickness skin graft (Figure 6).Pus drainage ceased three weeks post-operatively.This knee infection led to a spontaneous knee joint arthrodesis.At one year, he underwent knee arthrolysis and interposition arthroplasty after which he was able to walk with the aid of crutches and a prosthesis on the other leg.This was a 45 year-old diabetic male with scrotal Fournier's gangrene.The entire scrotum was debrided, and the testes buried in the medial thighs (Figure 7).He was referred to the Plastic surgery unit for scrotal reconstruction.After re-creation of the defect (Figure 8) an ALT flap was used to reconstruct a neo-scrotum (Figure 9).

Discussion
The ALT flap is perhaps the most versatile flap currently in use in reconstructive surgery; literature is replete with its use for different defects (4,5).It may be used for small defects as reported in case 2, but may also be used for extensive defects, as in case 1.While its foremost use is as a free flap, its use as a pedicled flap may also be unrivalled; the possibilities presented by pedicle size and length, the size of the flap that can be harvested, and the different components that can be included, as well as the fact that a reverse flap can be raised, make it a favourite reconstructive choice for defects within its area of reach (12,14).Gravvanis et al reported excellent blood flow in reverse ALT flaps they used for the coverage of knee and proximal leg defects (13).The reverse ALT proved useful in preserving the second lower extremity in Case 3.
The pedicled ALT flap is very attractive to the reconstructive surgeon in sub-Saharan Africa as it avails a versatile, dependable flap without the need for microsurgical anastomosis.Post-traumatic and postoncologic defects offer the most challenging reconstructive needs because of their complexity (1-3).
As evidenced by the four cases presented above, reconstruction options are as numerous as the defects requiring reconstruction.The fascial component of this flap has proven indispensable in the reconstruction of fascial defects of the anterior abdominal wall, especially in patients in whom the use of mesh is either contraindicated or unavailable.Five of the patients in the current series required abdominal fascia reconstruction -for these, mesh repair was not an option; four had ongoing abdominal or wound sepsis with exposed bowel, while the fifth, an adult with untreated ectopia vesicae, required a more complex reconstruction than mesh would have offered.Further, six of the patients reported in the current series were not expected to return for follow-up as they would have no means to do so.These patients were discharged home after their wounds were healed, and encouraged to stay within easy reach of the hospital prior to going back home.One patient was thought to have penoscrotal condylomata acuminatum preoperatively, but histology was reported as lymphedema.Clinically significant variations in the vascular anatomy of the ALT are well reported (6-8).In the current series, three patients (20% of 20 the ALT flaps raised) did not have identifiable ALT perforators in one limb.In all three patients, a Doppler signal suggestive of a perforator of the descending branch of the lateral circumflex femoral artery turned to be a perforator through the rectus femoris muscle, and an attempt to convert it so that we could use the ascending branch of the lateral circumflex femoral artery system was unsuccessful, and the flap harvesting was aborted in all cases.ALT flaps were successfully raised from the contralateral sides in two patients; these two flaps, and all the other flaps in the series conformed to the classic vascular anatomy.A third flap had abnormal veins, and although the flap appeared vascularized immediately after inset, we had to repeatedly manipulate the position of the multiple veins draining the main pedicle vein.Experience from this small series suggests that as found in studies in other races, the majority of black African patients have an ALT vascular anatomy consistent with that described in literature.There were two complete flap failures; one flap and (the flap tip necrosis in a reverse ALT) were associated with multi-drug resistant infections, while the second complete loss was the result of venous congestion.There were no other flaprelated complications, even though seven flaps had been used to reconstruct infected recipient sites.The average follow-up in this series is 24 months; there has been only one hypertrophic scar in a child (Table 1).

Conclusion
The pedicled ALT flap is an excellent reconstructive tool with very good results in the black African population.This versatile flap has low donor site

Figure 1 :
Figure 1: Necrotic rectus fascia and granulation tissue on bowel after a failed component separation

Figure 2 :
Figure 2: Three months after ALT reconstruction

Figure 3 :37Figure 4 :
Figure 3: Urethra obstructed by a urethral beard and stones.Note dark skin lining the urethra from a 'Singapore' flap

Figure 5 :
Figure 5: Infected, exposed knee joint and proximal leg

Figure 6 :
Figure 6: Defect reconstructed with a reverse ALT flap.