Overview
Definition:
Splenic flexure mobilization is a surgical maneuver performed during colectomy procedures involving the splenic flexure of the colon, which is the sharp bend between the transverse and descending colon
It involves dissecting the colon from its peritoneal attachments to achieve adequate length for a tension-free anastomosis, particularly in left colectomies, sigmoid colectomies, and anterior resections.
Epidemiology:
The necessity for splenic flexure mobilization arises in approximately 15-25% of left-sided colonic resections, depending on tumor location, patient anatomy, and the specific surgical approach
It is crucial for achieving oncological clearance and ensuring a safe anastomosis in pathologies such as diverticulitis, colorectal cancer, and inflammatory bowel disease affecting this region.
Clinical Significance:
Adequate mobilization is critical to avoid tension on the anastomosis, thereby reducing the risk of anastomotic leak, a major cause of morbidity and mortality in colorectal surgery
It allows for complete resection of diseased segments and facilitates proper alignment of the bowel ends for reconstruction
Inadequate mobilization can lead to compromised blood supply to the distal bowel, increasing the risk of ischemia and dehiscence.
Indications
Oncological Indications:
Resection of tumors located at or near the splenic flexure requiring adequate margins
En-bloc resection of involved lymph nodes and mesentery
Achieving sufficient distal margin for oncologic safety.
Benign Indications:
Management of complicated diverticulitis involving the splenic flexure
Resection of segments affected by inflammatory bowel disease (e.g., Crohn's disease, ulcerative colitis) with strictures or fistulae
Treatment of colonic volvulus or intussusception at this level.
Situational Indications:
When the proximal extent of the colon requires significant manipulation for tension-free anastomosis
In cases of redundant sigmoid colon or unfavorable anatomy that restricts bowel length
Essential for anterior resection with a low anastomosis.
Surgical Approaches
Traditional Open Approach:
Involves manual dissection with instruments
The surgeon identifies the white line of Toldt and follows it cephalad and laterally to free the splenic flexure
Care is taken to stay within the avascular plane to minimize bleeding and protect adjacent structures.
Laparoscopic Approach:
Utilizes laparoscopic instruments and visualization
The dissection is performed using energy devices (e.g., hook diathermy, ultrasonic dissectors) and graspers
The principles of dissection remain similar, focusing on the avascular plane, but requires meticulous technique and three-dimensional spatial awareness.
Robotic Assisted Approach:
Offers enhanced dexterity, visualization (3D high-definition), and precise instrument control
Facilitates intricate dissection in confined spaces
The surgeon controls robotic arms from a console, mimicking open surgical movements with greater precision.
Mobilization Techniques
Lateral To Medial Dissection:
Starting from the lateral peritoneal reflection of the descending colon, the surgeon incises the white line of Toldt and bluntly or sharply dissects medially towards the splenic flexure
This approach helps to preserve the vascular supply to the mobilized segment.
Medial To Lateral Dissection:
Less commonly, dissection may start from the medial aspect of the transverse colon and proceed laterally
This might be preferred in certain situations but carries a higher risk of injury to the middle colic artery or its branches.
Preservation Of Vascular Supply:
Key to successful mobilization is identifying and preserving the marginal artery of Drummond and the left colic artery
Dissection should remain in the correct plane, usually anterior to the retroperitoneal tissues, to avoid compromising blood flow to the mobilized bowel segment.
Complications
Bleeding:
Injury to the middle colic artery, left colic artery, or their branches
Peritoneal vessels
Management involves careful identification and ligation or coagulation.
Bowel Injury:
Perforation of the transverse colon, descending colon, or small bowel loops
Can occur due to excessive force or inadequate visualization
Requires immediate repair.
Nerve Injury:
Damage to sympathetic or parasympathetic nerves supplying the bowel, potentially leading to prolonged ileus or altered bowel function
Requires meticulous dissection.
Anastomotic Complications:
Tension on the anastomosis due to insufficient mobilization leading to ischemia, leak, or dehiscence
Careful assessment of bowel viability and tension is crucial before anastomosis.
Key Points
Exam Focus:
Understanding the anatomical boundaries of the splenic flexure
Recognizing the importance of the white line of Toldt
Awareness of the vascular supply (marginal artery of Drummond, left colic artery)
Key complications include bleeding and anastomotic leak.
Clinical Pearls:
Always ensure adequate mobilization for a tension-free anastomosis
Maintain orientation in the correct avascular plane
Assess bowel viability meticulously before proceeding with anastomosis
Intraoperative imaging or pressure measurements can guide adequacy of mobilization.
Common Mistakes:
Dissecting too far medially, risking injury to pancreatic tail or spleen
Inadequate mobilization, leading to tension on the anastomosis
Failing to identify and ligate significant vessels
Sacrificing essential vascular supply to the distal bowel segment.